_ 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::hash::{Hash, Hasher};
  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::{DecodeError, MAX_VALUE_MSAT};
  94 use crate::offers::merkle::{TaggedHash, TlvStream};
  95 use crate::offers::parse::{Bech32Encode, Bolt12ParseError, Bolt12SemanticError, ParsedMessage};
  96 use crate::offers::signer::{Metadata, MetadataMaterial, self};
  97 use crate::util::ser::{HighZeroBytesDroppedBigSize, Readable, WithoutLength, Writeable, Writer};
  98 use crate::util::string::PrintableString;
  99
 100 #[cfg(not(c_bindings))]
 101 use {
 102         crate::offers::invoice_request::{DerivedPayerId, ExplicitPayerId, InvoiceRequestBuilder},
 103 };
 104 #[cfg(c_bindings)]
 105 use {
 106         crate::offers::invoice_request::{InvoiceRequestWithDerivedPayerIdBuilder, InvoiceRequestWithExplicitPayerIdBuilder},
 107 };
 108
 109 #[allow(unused_imports)]
 110 use crate::prelude::*;
 111
 112 #[cfg(feature = "std")]
 113 use std::time::SystemTime;
 114
 115 pub(super) const IV_BYTES: &[u8; IV_LEN] = b"LDK Offer ~~~~~~";
 116
 117 /// An identifier for an [`Offer`] built using [`DerivedMetadata`].
 118 #[derive(Clone, Copy, Debug, PartialEq)]
 119 pub struct OfferId(pub [u8; 32]);
 120
 121 impl OfferId {
 122         const ID_TAG: &'static str = "LDK Offer ID";
 123
 124         fn from_valid_offer_tlv_stream(bytes: &[u8]) -> Self {
 125                 let tagged_hash = TaggedHash::new(Self::ID_TAG, &bytes);
 126                 Self(tagged_hash.to_bytes())
 127         }
 128 }
 129
 130 impl Writeable for OfferId {
 131         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 132                 self.0.write(w)
 133         }
 134 }
 135
 136 impl Readable for OfferId {
 137         fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
 138                 Ok(OfferId(Readable::read(r)?))
 139         }
 140 }
 141
 142 /// Builds an [`Offer`] for the "offer to be paid" flow.
 143 ///
 144 /// See [module-level documentation] for usage.
 145 ///
 146 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 147 ///
 148 /// [module-level documentation]: self
 149 pub struct OfferBuilder<'a, M: MetadataStrategy, T: secp256k1::Signing> {
 150         offer: OfferContents,
 151         metadata_strategy: core::marker::PhantomData<M>,
 152         secp_ctx: Option<&'a Secp256k1<T>>,
 153 }
 154
 155 /// Builds an [`Offer`] for the "offer to be paid" flow.
 156 ///
 157 /// See [module-level documentation] for usage.
 158 ///
 159 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 160 ///
 161 /// [module-level documentation]: self
 162 #[cfg(c_bindings)]
 163 pub struct OfferWithExplicitMetadataBuilder<'a> {
 164         offer: OfferContents,
 165         metadata_strategy: core::marker::PhantomData<ExplicitMetadata>,
 166         secp_ctx: Option<&'a Secp256k1<secp256k1::All>>,
 167 }
 168
 169 /// Builds an [`Offer`] for the "offer to be paid" flow.
 170 ///
 171 /// See [module-level documentation] for usage.
 172 ///
 173 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 174 ///
 175 /// [module-level documentation]: self
 176 #[cfg(c_bindings)]
 177 pub struct OfferWithDerivedMetadataBuilder<'a> {
 178         offer: OfferContents,
 179         metadata_strategy: core::marker::PhantomData<DerivedMetadata>,
 180         secp_ctx: Option<&'a Secp256k1<secp256k1::All>>,
 181 }
 182
 183 /// Indicates how [`Offer::metadata`] may be set.
 184 ///
 185 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 186 pub trait MetadataStrategy {}
 187
 188 /// [`Offer::metadata`] may be explicitly set or left empty.
 189 ///
 190 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 191 pub struct ExplicitMetadata {}
 192
 193 /// [`Offer::metadata`] will be derived.
 194 ///
 195 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 196 pub struct DerivedMetadata {}
 197
 198 impl MetadataStrategy for ExplicitMetadata {}
 199
 200 impl MetadataStrategy for DerivedMetadata {}
 201
 202 macro_rules! offer_explicit_metadata_builder_methods { (
 203         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr
 204 ) => {
 205         /// Creates a new builder for an offer setting the [`Offer::description`] and using the
 206         /// [`Offer::signing_pubkey`] for signing invoices. The associated secret key must be remembered
 207         /// while the offer is valid.
 208         ///
 209         /// Use a different pubkey per offer to avoid correlating offers.
 210         ///
 211         /// # Note
 212         ///
 213         /// If constructing an [`Offer`] for use with a [`ChannelManager`], use
 214         /// [`ChannelManager::create_offer_builder`] instead of [`OfferBuilder::new`].
 215         ///
 216         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 217         /// [`ChannelManager::create_offer_builder`]: crate::ln::channelmanager::ChannelManager::create_offer_builder
 218         pub fn new(description: String, signing_pubkey: PublicKey) -> Self {
 219                 Self {
 220                         offer: OfferContents {
 221                                 chains: None, metadata: None, amount: None, description,
 222                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 223                                 supported_quantity: Quantity::One, signing_pubkey,
 224                         },
 225                         metadata_strategy: core::marker::PhantomData,
 226                         secp_ctx: None,
 227                 }
 228         }
 229
 230         /// Sets the [`Offer::metadata`] to the given bytes.
 231         ///
 232         /// Successive calls to this method will override the previous setting.
 233         pub fn metadata(mut $self: $self_type, metadata: Vec<u8>) -> Result<$return_type, Bolt12SemanticError> {
 234                 $self.offer.metadata = Some(Metadata::Bytes(metadata));
 235                 Ok($return_value)
 236         }
 237 } }
 238
 239 macro_rules! offer_derived_metadata_builder_methods { ($secp_context: ty) => {
 240         /// Similar to [`OfferBuilder::new`] except, if [`OfferBuilder::path`] is called, the signing
 241         /// pubkey is derived from the given [`ExpandedKey`] and [`EntropySource`]. This provides
 242         /// recipient privacy by using a different signing pubkey for each offer. Otherwise, the
 243         /// provided `node_id` is used for the signing pubkey.
 244         ///
 245         /// Also, sets the metadata when [`OfferBuilder::build`] is called such that it can be used by
 246         /// [`InvoiceRequest::verify`] to determine if the request was produced for the offer given an
 247         /// [`ExpandedKey`].
 248         ///
 249         /// [`InvoiceRequest::verify`]: crate::offers::invoice_request::InvoiceRequest::verify
 250         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 251         pub fn deriving_signing_pubkey<ES: Deref>(
 252                 description: String, node_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 253                 secp_ctx: &'a Secp256k1<$secp_context>
 254         ) -> Self where ES::Target: EntropySource {
 255                 let nonce = Nonce::from_entropy_source(entropy_source);
 256                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, None);
 257                 let metadata = Metadata::DerivedSigningPubkey(derivation_material);
 258                 Self {
 259                         offer: OfferContents {
 260                                 chains: None, metadata: Some(metadata), amount: None, description,
 261                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 262                                 supported_quantity: Quantity::One, signing_pubkey: node_id,
 263                         },
 264                         metadata_strategy: core::marker::PhantomData,
 265                         secp_ctx: Some(secp_ctx),
 266                 }
 267         }
 268 } }
 269
 270 macro_rules! offer_builder_methods { (
 271         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
 272 ) => {
 273         /// Adds the chain hash of the given [`Network`] to [`Offer::chains`]. If not called,
 274         /// the chain hash of [`Network::Bitcoin`] is assumed to be the only one supported.
 275         ///
 276         /// See [`Offer::chains`] on how this relates to the payment currency.
 277         ///
 278         /// Successive calls to this method will add another chain hash.
 279         pub fn chain($self: $self_type, network: Network) -> $return_type {
 280                 $self.chain_hash(ChainHash::using_genesis_block(network))
 281         }
 282
 283         /// Adds the [`ChainHash`] to [`Offer::chains`]. If not called, the chain hash of
 284         /// [`Network::Bitcoin`] is assumed to be the only one supported.
 285         ///
 286         /// See [`Offer::chains`] on how this relates to the payment currency.
 287         ///
 288         /// Successive calls to this method will add another chain hash.
 289         pub(crate) fn chain_hash($($self_mut)* $self: $self_type, chain: ChainHash) -> $return_type {
 290                 let chains = $self.offer.chains.get_or_insert_with(Vec::new);
 291                 if !chains.contains(&chain) {
 292                         chains.push(chain);
 293                 }
 294
 295                 $return_value
 296         }
 297
 298         /// Sets the [`Offer::amount`] as an [`Amount::Bitcoin`].
 299         ///
 300         /// Successive calls to this method will override the previous setting.
 301         pub fn amount_msats($self: $self_type, amount_msats: u64) -> $return_type {
 302                 $self.amount(Amount::Bitcoin { amount_msats })
 303         }
 304
 305         /// Sets the [`Offer::amount`].
 306         ///
 307         /// Successive calls to this method will override the previous setting.
 308         pub(super) fn amount($($self_mut)* $self: $self_type, amount: Amount) -> $return_type {
 309                 $self.offer.amount = Some(amount);
 310                 $return_value
 311         }
 312
 313         /// Sets the [`Offer::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
 314         /// already passed is valid and can be checked for using [`Offer::is_expired`].
 315         ///
 316         /// Successive calls to this method will override the previous setting.
 317         pub fn absolute_expiry($($self_mut)* $self: $self_type, absolute_expiry: Duration) -> $return_type {
 318                 $self.offer.absolute_expiry = Some(absolute_expiry);
 319                 $return_value
 320         }
 321
 322         /// Sets the [`Offer::issuer`].
 323         ///
 324         /// Successive calls to this method will override the previous setting.
 325         pub fn issuer($($self_mut)* $self: $self_type, issuer: String) -> $return_type {
 326                 $self.offer.issuer = Some(issuer);
 327                 $return_value
 328         }
 329
 330         /// Adds a blinded path to [`Offer::paths`]. Must include at least one path if only connected by
 331         /// private channels or if [`Offer::signing_pubkey`] is not a public node id.
 332         ///
 333         /// Successive calls to this method will add another blinded path. Caller is responsible for not
 334         /// adding duplicate paths.
 335         pub fn path($($self_mut)* $self: $self_type, path: BlindedPath) -> $return_type {
 336                 $self.offer.paths.get_or_insert_with(Vec::new).push(path);
 337                 $return_value
 338         }
 339
 340         /// Sets the quantity of items for [`Offer::supported_quantity`]. If not called, defaults to
 341         /// [`Quantity::One`].
 342         ///
 343         /// Successive calls to this method will override the previous setting.
 344         pub fn supported_quantity($($self_mut)* $self: $self_type, quantity: Quantity) -> $return_type {
 345                 $self.offer.supported_quantity = quantity;
 346                 $return_value
 347         }
 348
 349         /// Builds an [`Offer`] from the builder's settings.
 350         pub fn build($($self_mut)* $self: $self_type) -> Result<Offer, Bolt12SemanticError> {
 351                 match $self.offer.amount {
 352                         Some(Amount::Bitcoin { amount_msats }) => {
 353                                 if amount_msats > MAX_VALUE_MSAT {
 354                                         return Err(Bolt12SemanticError::InvalidAmount);
 355                                 }
 356                         },
 357                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 358                         None => {},
 359                 }
 360
 361                 if let Some(chains) = &$self.offer.chains {
 362                         if chains.len() == 1 && chains[0] == $self.offer.implied_chain() {
 363                                 $self.offer.chains = None;
 364                         }
 365                 }
 366
 367                 Ok($self.build_without_checks())
 368         }
 369
 370         fn build_without_checks($($self_mut)* $self: $self_type) -> Offer {
 371                 // Create the metadata for stateless verification of an InvoiceRequest.
 372                 if let Some(mut metadata) = $self.offer.metadata.take() {
 373                         if metadata.has_derivation_material() {
 374                                 if $self.offer.paths.is_none() {
 375                                         metadata = metadata.without_keys();
 376                                 }
 377
 378                                 let mut tlv_stream = $self.offer.as_tlv_stream();
 379                                 debug_assert_eq!(tlv_stream.metadata, None);
 380                                 tlv_stream.metadata = None;
 381                                 if metadata.derives_recipient_keys() {
 382                                         tlv_stream.node_id = None;
 383                                 }
 384
 385                                 let (derived_metadata, keys) = metadata.derive_from(tlv_stream, $self.secp_ctx);
 386                                 metadata = derived_metadata;
 387                                 if let Some(keys) = keys {
 388                                         $self.offer.signing_pubkey = keys.public_key();
 389                                 }
 390                         }
 391
 392                         $self.offer.metadata = Some(metadata);
 393                 }
 394
 395                 let mut bytes = Vec::new();
 396                 $self.offer.write(&mut bytes).unwrap();
 397
 398                 let id = OfferId::from_valid_offer_tlv_stream(&bytes);
 399
 400                 Offer {
 401                         bytes,
 402                         #[cfg(not(c_bindings))]
 403                         contents: $self.offer,
 404                         #[cfg(c_bindings)]
 405                         contents: $self.offer.clone(),
 406                         id,
 407                 }
 408         }
 409 } }
 410
 411 #[cfg(test)]
 412 macro_rules! offer_builder_test_methods { (
 413         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
 414 ) => {
 415         #[cfg_attr(c_bindings, allow(dead_code))]
 416         fn features_unchecked($($self_mut)* $self: $self_type, features: OfferFeatures) -> $return_type {
 417                 $self.offer.features = features;
 418                 $return_value
 419         }
 420
 421         #[cfg_attr(c_bindings, allow(dead_code))]
 422         pub(crate) fn clear_chains($($self_mut)* $self: $self_type) -> $return_type {
 423                 $self.offer.chains = None;
 424                 $return_value
 425         }
 426
 427         #[cfg_attr(c_bindings, allow(dead_code))]
 428         pub(crate) fn clear_paths($($self_mut)* $self: $self_type) -> $return_type {
 429                 $self.offer.paths = None;
 430                 $return_value
 431         }
 432
 433         #[cfg_attr(c_bindings, allow(dead_code))]
 434         pub(super) fn build_unchecked($self: $self_type) -> Offer {
 435                 $self.build_without_checks()
 436         }
 437 } }
 438
 439 impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
 440         offer_builder_methods!(self, Self, Self, self, mut);
 441
 442         #[cfg(test)]
 443         offer_builder_test_methods!(self, Self, Self, self, mut);
 444 }
 445
 446 impl<'a> OfferBuilder<'a, ExplicitMetadata, secp256k1::SignOnly> {
 447         offer_explicit_metadata_builder_methods!(self, Self, Self, self);
 448 }
 449
 450 impl<'a, T: secp256k1::Signing> OfferBuilder<'a, DerivedMetadata, T> {
 451         offer_derived_metadata_builder_methods!(T);
 452 }
 453
 454 #[cfg(all(c_bindings, not(test)))]
 455 impl<'a> OfferWithExplicitMetadataBuilder<'a> {
 456         offer_explicit_metadata_builder_methods!(self, &mut Self, (), ());
 457         offer_builder_methods!(self, &mut Self, (), ());
 458 }
 459
 460 #[cfg(all(c_bindings, test))]
 461 impl<'a> OfferWithExplicitMetadataBuilder<'a> {
 462         offer_explicit_metadata_builder_methods!(self, &mut Self, &mut Self, self);
 463         offer_builder_methods!(self, &mut Self, &mut Self, self);
 464         offer_builder_test_methods!(self, &mut Self, &mut Self, self);
 465 }
 466
 467 #[cfg(all(c_bindings, not(test)))]
 468 impl<'a> OfferWithDerivedMetadataBuilder<'a> {
 469         offer_derived_metadata_builder_methods!(secp256k1::All);
 470         offer_builder_methods!(self, &mut Self, (), ());
 471 }
 472
 473 #[cfg(all(c_bindings, test))]
 474 impl<'a> OfferWithDerivedMetadataBuilder<'a> {
 475         offer_derived_metadata_builder_methods!(secp256k1::All);
 476         offer_builder_methods!(self, &mut Self, &mut Self, self);
 477         offer_builder_test_methods!(self, &mut Self, &mut Self, self);
 478 }
 479
 480 #[cfg(c_bindings)]
 481 impl<'a> From<OfferBuilder<'a, DerivedMetadata, secp256k1::All>>
 482 for OfferWithDerivedMetadataBuilder<'a> {
 483         fn from(builder: OfferBuilder<'a, DerivedMetadata, secp256k1::All>) -> Self {
 484                 let OfferBuilder { offer, metadata_strategy, secp_ctx } = builder;
 485
 486                 Self { offer, metadata_strategy, secp_ctx }
 487         }
 488 }
 489
 490 #[cfg(c_bindings)]
 491 impl<'a> From<OfferWithDerivedMetadataBuilder<'a>>
 492 for OfferBuilder<'a, DerivedMetadata, secp256k1::All> {
 493         fn from(builder: OfferWithDerivedMetadataBuilder<'a>) -> Self {
 494                 let OfferWithDerivedMetadataBuilder { offer, metadata_strategy, secp_ctx } = builder;
 495
 496                 Self { offer, metadata_strategy, secp_ctx }
 497         }
 498 }
 499
 500 /// An `Offer` is a potentially long-lived proposal for payment of a good or service.
 501 ///
 502 /// An offer is a precursor to an [`InvoiceRequest`]. A merchant publishes an offer from which a
 503 /// customer may request an [`Bolt12Invoice`] for a specific quantity and using an amount sufficient
 504 /// to cover that quantity (i.e., at least `quantity * amount`). See [`Offer::amount`].
 505 ///
 506 /// Offers may be denominated in currency other than bitcoin but are ultimately paid using the
 507 /// latter.
 508 ///
 509 /// Through the use of [`BlindedPath`]s, offers provide recipient privacy.
 510 ///
 511 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 512 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 513 #[derive(Clone, Debug)]
 514 pub struct Offer {
 515         // The serialized offer. Needed when creating an `InvoiceRequest` if the offer contains unknown
 516         // fields.
 517         pub(super) bytes: Vec<u8>,
 518         pub(super) contents: OfferContents,
 519         id: OfferId,
 520 }
 521
 522 /// The contents of an [`Offer`], which may be shared with an [`InvoiceRequest`] or a
 523 /// [`Bolt12Invoice`].
 524 ///
 525 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 526 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 527 #[derive(Clone, Debug)]
 528 #[cfg_attr(test, derive(PartialEq))]
 529 pub(super) struct OfferContents {
 530         chains: Option<Vec<ChainHash>>,
 531         metadata: Option<Metadata>,
 532         amount: Option<Amount>,
 533         description: String,
 534         features: OfferFeatures,
 535         absolute_expiry: Option<Duration>,
 536         issuer: Option<String>,
 537         paths: Option<Vec<BlindedPath>>,
 538         supported_quantity: Quantity,
 539         signing_pubkey: PublicKey,
 540 }
 541
 542 macro_rules! offer_accessors { ($self: ident, $contents: expr) => {
 543         // TODO: Return a slice once ChainHash has constants.
 544         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1283
 545         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1286
 546         /// The chains that may be used when paying a requested invoice (e.g., bitcoin mainnet).
 547         /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats)
 548         /// for the selected chain.
 549         pub fn chains(&$self) -> Vec<bitcoin::blockdata::constants::ChainHash> {
 550                 $contents.chains()
 551         }
 552
 553         // TODO: Link to corresponding method in `InvoiceRequest`.
 554         /// Opaque bytes set by the originator. Useful for authentication and validating fields since it
 555         /// is reflected in `invoice_request` messages along with all the other fields from the `offer`.
 556         pub fn metadata(&$self) -> Option<&Vec<u8>> {
 557                 $contents.metadata()
 558         }
 559
 560         /// The minimum amount required for a successful payment of a single item.
 561         pub fn amount(&$self) -> Option<&$crate::offers::offer::Amount> {
 562                 $contents.amount()
 563         }
 564
 565         /// A complete description of the purpose of the payment. Intended to be displayed to the user
 566         /// but with the caveat that it has not been verified in any way.
 567         pub fn description(&$self) -> $crate::util::string::PrintableString {
 568                 $contents.description()
 569         }
 570
 571         /// Features pertaining to the offer.
 572         pub fn offer_features(&$self) -> &$crate::ln::features::OfferFeatures {
 573                 &$contents.features()
 574         }
 575
 576         /// Duration since the Unix epoch when an invoice should no longer be requested.
 577         ///
 578         /// If `None`, the offer does not expire.
 579         pub fn absolute_expiry(&$self) -> Option<core::time::Duration> {
 580                 $contents.absolute_expiry()
 581         }
 582
 583         /// The issuer of the offer, possibly beginning with `user@domain` or `domain`. Intended to be
 584         /// displayed to the user but with the caveat that it has not been verified in any way.
 585         pub fn issuer(&$self) -> Option<$crate::util::string::PrintableString> {
 586                 $contents.issuer()
 587         }
 588
 589         /// Paths to the recipient originating from publicly reachable nodes. Blinded paths provide
 590         /// recipient privacy by obfuscating its node id.
 591         pub fn paths(&$self) -> &[$crate::blinded_path::BlindedPath] {
 592                 $contents.paths()
 593         }
 594
 595         /// The quantity of items supported.
 596         pub fn supported_quantity(&$self) -> $crate::offers::offer::Quantity {
 597                 $contents.supported_quantity()
 598         }
 599
 600         /// The public key used by the recipient to sign invoices.
 601         pub fn signing_pubkey(&$self) -> bitcoin::secp256k1::PublicKey {
 602                 $contents.signing_pubkey()
 603         }
 604 } }
 605
 606 impl Offer {
 607         offer_accessors!(self, self.contents);
 608
 609         /// Returns the id of the offer.
 610         pub fn id(&self) -> OfferId {
 611                 self.id
 612         }
 613
 614         pub(super) fn implied_chain(&self) -> ChainHash {
 615                 self.contents.implied_chain()
 616         }
 617
 618         /// Returns whether the given chain is supported by the offer.
 619         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 620                 self.contents.supports_chain(chain)
 621         }
 622
 623         /// Whether the offer has expired.
 624         #[cfg(feature = "std")]
 625         pub fn is_expired(&self) -> bool {
 626                 self.contents.is_expired()
 627         }
 628
 629         /// Whether the offer has expired given the duration since the Unix epoch.
 630         pub fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 631                 self.contents.is_expired_no_std(duration_since_epoch)
 632         }
 633
 634         /// Returns whether the given quantity is valid for the offer.
 635         pub fn is_valid_quantity(&self, quantity: u64) -> bool {
 636                 self.contents.is_valid_quantity(quantity)
 637         }
 638
 639         /// Returns whether a quantity is expected in an [`InvoiceRequest`] for the offer.
 640         ///
 641         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 642         pub fn expects_quantity(&self) -> bool {
 643                 self.contents.expects_quantity()
 644         }
 645 }
 646
 647 macro_rules! request_invoice_derived_payer_id { ($self: ident, $builder: ty) => {
 648         /// Similar to [`Offer::request_invoice`] except it:
 649         /// - derives the [`InvoiceRequest::payer_id`] such that a different key can be used for each
 650         ///   request,
 651         /// - sets [`InvoiceRequest::payer_metadata`] when [`InvoiceRequestBuilder::build`] is called
 652         ///   such that it can be used by [`Bolt12Invoice::verify`] to determine if the invoice was
 653         ///   requested using a base [`ExpandedKey`] from which the payer id was derived, and
 654         /// - includes the [`PaymentId`] encrypted in [`InvoiceRequest::payer_metadata`] so that it can
 655         ///   be used when sending the payment for the requested invoice.
 656         ///
 657         /// Useful to protect the sender's privacy.
 658         ///
 659         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 660         /// [`InvoiceRequest::payer_metadata`]: crate::offers::invoice_request::InvoiceRequest::payer_metadata
 661         /// [`Bolt12Invoice::verify`]: crate::offers::invoice::Bolt12Invoice::verify
 662         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 663         pub fn request_invoice_deriving_payer_id<
 664                 'a, 'b, ES: Deref,
 665                 #[cfg(not(c_bindings))]
 666                 T: secp256k1::Signing
 667         >(
 668                 &'a $self, expanded_key: &ExpandedKey, entropy_source: ES,
 669                 #[cfg(not(c_bindings))]
 670                 secp_ctx: &'b Secp256k1<T>,
 671                 #[cfg(c_bindings)]
 672                 secp_ctx: &'b Secp256k1<secp256k1::All>,
 673                 payment_id: PaymentId
 674         ) -> Result<$builder, Bolt12SemanticError>
 675         where
 676                 ES::Target: EntropySource,
 677         {
 678                 if $self.offer_features().requires_unknown_bits() {
 679                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 680                 }
 681
 682                 Ok(<$builder>::deriving_payer_id($self, expanded_key, entropy_source, secp_ctx, payment_id))
 683         }
 684 } }
 685
 686 macro_rules! request_invoice_explicit_payer_id { ($self: ident, $builder: ty) => {
 687         /// Similar to [`Offer::request_invoice_deriving_payer_id`] except uses `payer_id` for the
 688         /// [`InvoiceRequest::payer_id`] instead of deriving a different key for each request.
 689         ///
 690         /// Useful for recurring payments using the same `payer_id` with different invoices.
 691         ///
 692         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 693         pub fn request_invoice_deriving_metadata<ES: Deref>(
 694                 &$self, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 695                 payment_id: PaymentId
 696         ) -> Result<$builder, Bolt12SemanticError>
 697         where
 698                 ES::Target: EntropySource,
 699         {
 700                 if $self.offer_features().requires_unknown_bits() {
 701                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 702                 }
 703
 704                 Ok(<$builder>::deriving_metadata($self, payer_id, expanded_key, entropy_source, payment_id))
 705         }
 706
 707         /// Creates an [`InvoiceRequestBuilder`] for the offer with the given `metadata` and `payer_id`,
 708         /// which will be reflected in the `Bolt12Invoice` response.
 709         ///
 710         /// The `metadata` is useful for including information about the derivation of `payer_id` such
 711         /// that invoice response handling can be stateless. Also serves as payer-provided entropy while
 712         /// hashing in the signature calculation.
 713         ///
 714         /// This should not leak any information such as by using a simple BIP-32 derivation path.
 715         /// Otherwise, payments may be correlated.
 716         ///
 717         /// Errors if the offer contains unknown required features.
 718         ///
 719         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 720         pub fn request_invoice(
 721                 &$self, metadata: Vec<u8>, payer_id: PublicKey
 722         ) -> Result<$builder, Bolt12SemanticError> {
 723                 if $self.offer_features().requires_unknown_bits() {
 724                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 725                 }
 726
 727                 Ok(<$builder>::new($self, metadata, payer_id))
 728         }
 729 } }
 730
 731 #[cfg(not(c_bindings))]
 732 impl Offer {
 733         request_invoice_derived_payer_id!(self, InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T>);
 734         request_invoice_explicit_payer_id!(self, InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>);
 735 }
 736
 737 #[cfg(c_bindings)]
 738 impl Offer {
 739         request_invoice_derived_payer_id!(self, InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b>);
 740         request_invoice_explicit_payer_id!(self, InvoiceRequestWithExplicitPayerIdBuilder);
 741 }
 742
 743 #[cfg(test)]
 744 impl Offer {
 745         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 746                 self.contents.as_tlv_stream()
 747         }
 748 }
 749
 750 impl AsRef<[u8]> for Offer {
 751         fn as_ref(&self) -> &[u8] {
 752                 &self.bytes
 753         }
 754 }
 755
 756 impl PartialEq for Offer {
 757         fn eq(&self, other: &Self) -> bool {
 758                 self.bytes.eq(&other.bytes)
 759         }
 760 }
 761
 762 impl Eq for Offer {}
 763
 764 impl Hash for Offer {
 765         fn hash<H: Hasher>(&self, state: &mut H) {
 766                 self.bytes.hash(state);
 767         }
 768 }
 769
 770 impl OfferContents {
 771         pub fn chains(&self) -> Vec<ChainHash> {
 772                 self.chains.as_ref().cloned().unwrap_or_else(|| vec![self.implied_chain()])
 773         }
 774
 775         pub fn implied_chain(&self) -> ChainHash {
 776                 ChainHash::using_genesis_block(Network::Bitcoin)
 777         }
 778
 779         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 780                 self.chains().contains(&chain)
 781         }
 782
 783         pub fn metadata(&self) -> Option<&Vec<u8>> {
 784                 self.metadata.as_ref().and_then(|metadata| metadata.as_bytes())
 785         }
 786
 787         pub fn amount(&self) -> Option<&Amount> {
 788                 self.amount.as_ref()
 789         }
 790
 791         pub fn description(&self) -> PrintableString {
 792                 PrintableString(&self.description)
 793         }
 794
 795         pub fn features(&self) -> &OfferFeatures {
 796                 &self.features
 797         }
 798
 799         pub fn absolute_expiry(&self) -> Option<Duration> {
 800                 self.absolute_expiry
 801         }
 802
 803         #[cfg(feature = "std")]
 804         pub(super) fn is_expired(&self) -> bool {
 805                 SystemTime::UNIX_EPOCH
 806                         .elapsed()
 807                         .map(|duration_since_epoch| self.is_expired_no_std(duration_since_epoch))
 808                         .unwrap_or(false)
 809         }
 810
 811         pub(super) fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 812                 self.absolute_expiry
 813                         .map(|absolute_expiry| duration_since_epoch > absolute_expiry)
 814                         .unwrap_or(false)
 815         }
 816
 817         pub fn issuer(&self) -> Option<PrintableString> {
 818                 self.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 819         }
 820
 821         pub fn paths(&self) -> &[BlindedPath] {
 822                 self.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 823         }
 824
 825         pub(super) fn check_amount_msats_for_quantity(
 826                 &self, amount_msats: Option<u64>, quantity: Option<u64>
 827         ) -> Result<(), Bolt12SemanticError> {
 828                 let offer_amount_msats = match self.amount {
 829                         None => 0,
 830                         Some(Amount::Bitcoin { amount_msats }) => amount_msats,
 831                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 832                 };
 833
 834                 if !self.expects_quantity() || quantity.is_some() {
 835                         let expected_amount_msats = offer_amount_msats.checked_mul(quantity.unwrap_or(1))
 836                                 .ok_or(Bolt12SemanticError::InvalidAmount)?;
 837                         let amount_msats = amount_msats.unwrap_or(expected_amount_msats);
 838
 839                         if amount_msats < expected_amount_msats {
 840                                 return Err(Bolt12SemanticError::InsufficientAmount);
 841                         }
 842
 843                         if amount_msats > MAX_VALUE_MSAT {
 844                                 return Err(Bolt12SemanticError::InvalidAmount);
 845                         }
 846                 }
 847
 848                 Ok(())
 849         }
 850
 851         pub fn supported_quantity(&self) -> Quantity {
 852                 self.supported_quantity
 853         }
 854
 855         pub(super) fn check_quantity(&self, quantity: Option<u64>) -> Result<(), Bolt12SemanticError> {
 856                 let expects_quantity = self.expects_quantity();
 857                 match quantity {
 858                         None if expects_quantity => Err(Bolt12SemanticError::MissingQuantity),
 859                         Some(_) if !expects_quantity => Err(Bolt12SemanticError::UnexpectedQuantity),
 860                         Some(quantity) if !self.is_valid_quantity(quantity) => {
 861                                 Err(Bolt12SemanticError::InvalidQuantity)
 862                         },
 863                         _ => Ok(()),
 864                 }
 865         }
 866
 867         fn is_valid_quantity(&self, quantity: u64) -> bool {
 868                 match self.supported_quantity {
 869                         Quantity::Bounded(n) => quantity <= n.get(),
 870                         Quantity::Unbounded => quantity > 0,
 871                         Quantity::One => quantity == 1,
 872                 }
 873         }
 874
 875         fn expects_quantity(&self) -> bool {
 876                 match self.supported_quantity {
 877                         Quantity::Bounded(_) => true,
 878                         Quantity::Unbounded => true,
 879                         Quantity::One => false,
 880                 }
 881         }
 882
 883         pub(super) fn signing_pubkey(&self) -> PublicKey {
 884                 self.signing_pubkey
 885         }
 886
 887         /// Verifies that the offer metadata was produced from the offer in the TLV stream.
 888         pub(super) fn verify<T: secp256k1::Signing>(
 889                 &self, bytes: &[u8], key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 890         ) -> Result<Option<KeyPair>, ()> {
 891                 match self.metadata() {
 892                         Some(metadata) => {
 893                                 let tlv_stream = TlvStream::new(bytes).range(OFFER_TYPES).filter(|record| {
 894                                         match record.r#type {
 895                                                 OFFER_METADATA_TYPE => false,
 896                                                 OFFER_NODE_ID_TYPE => {
 897                                                         !self.metadata.as_ref().unwrap().derives_recipient_keys()
 898                                                 },
 899                                                 _ => true,
 900                                         }
 901                                 });
 902                                 signer::verify_recipient_metadata(
 903                                         metadata, key, IV_BYTES, self.signing_pubkey(), tlv_stream, secp_ctx
 904                                 )
 905                         },
 906                         None => Err(()),
 907                 }
 908         }
 909
 910         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 911                 let (currency, amount) = match &self.amount {
 912                         None => (None, None),
 913                         Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)),
 914                         Some(Amount::Currency { iso4217_code, amount }) => (
 915                                 Some(iso4217_code), Some(*amount)
 916                         ),
 917                 };
 918
 919                 let features = {
 920                         if self.features == OfferFeatures::empty() { None } else { Some(&self.features) }
 921                 };
 922
 923                 OfferTlvStreamRef {
 924                         chains: self.chains.as_ref(),
 925                         metadata: self.metadata(),
 926                         currency,
 927                         amount,
 928                         description: Some(&self.description),
 929                         features,
 930                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 931                         paths: self.paths.as_ref(),
 932                         issuer: self.issuer.as_ref(),
 933                         quantity_max: self.supported_quantity.to_tlv_record(),
 934                         node_id: Some(&self.signing_pubkey),
 935                 }
 936         }
 937 }
 938
 939 impl Writeable for Offer {
 940         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 941                 WithoutLength(&self.bytes).write(writer)
 942         }
 943 }
 944
 945 impl Writeable for OfferContents {
 946         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 947                 self.as_tlv_stream().write(writer)
 948         }
 949 }
 950
 951 /// The minimum amount required for an item in an [`Offer`], denominated in either bitcoin or
 952 /// another currency.
 953 #[derive(Clone, Debug, PartialEq)]
 954 pub enum Amount {
 955         /// An amount of bitcoin.
 956         Bitcoin {
 957                 /// The amount in millisatoshi.
 958                 amount_msats: u64,
 959         },
 960         /// An amount of currency specified using ISO 4712.
 961         Currency {
 962                 /// The currency that the amount is denominated in.
 963                 iso4217_code: CurrencyCode,
 964                 /// The amount in the currency unit adjusted by the ISO 4712 exponent (e.g., USD cents).
 965                 amount: u64,
 966         },
 967 }
 968
 969 /// An ISO 4712 three-letter currency code (e.g., USD).
 970 pub type CurrencyCode = [u8; 3];
 971
 972 /// Quantity of items supported by an [`Offer`].
 973 #[derive(Clone, Copy, Debug, PartialEq)]
 974 pub enum Quantity {
 975         /// Up to a specific number of items (inclusive). Use when more than one item can be requested
 976         /// but is limited (e.g., because of per customer or inventory limits).
 977         ///
 978         /// May be used with `NonZeroU64::new(1)` but prefer to use [`Quantity::One`] if only one item
 979         /// is supported.
 980         Bounded(NonZeroU64),
 981         /// One or more items. Use when more than one item can be requested without any limit.
 982         Unbounded,
 983         /// Only one item. Use when only a single item can be requested.
 984         One,
 985 }
 986
 987 impl Quantity {
 988         fn to_tlv_record(&self) -> Option<u64> {
 989                 match self {
 990                         Quantity::Bounded(n) => Some(n.get()),
 991                         Quantity::Unbounded => Some(0),
 992                         Quantity::One => None,
 993                 }
 994         }
 995 }
 996
 997 /// Valid type range for offer TLV records.
 998 pub(super) const OFFER_TYPES: core::ops::Range<u64> = 1..80;
 999
1000 /// TLV record type for [`Offer::metadata`].
1001 const OFFER_METADATA_TYPE: u64 = 4;
1002
1003 /// TLV record type for [`Offer::signing_pubkey`].
1004 const OFFER_NODE_ID_TYPE: u64 = 22;
1005
1006 tlv_stream!(OfferTlvStream, OfferTlvStreamRef, OFFER_TYPES, {
1007         (2, chains: (Vec<ChainHash>, WithoutLength)),
1008         (OFFER_METADATA_TYPE, metadata: (Vec<u8>, WithoutLength)),
1009         (6, currency: CurrencyCode),
1010         (8, amount: (u64, HighZeroBytesDroppedBigSize)),
1011         (10, description: (String, WithoutLength)),
1012         (12, features: (OfferFeatures, WithoutLength)),
1013         (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)),
1014         (16, paths: (Vec<BlindedPath>, WithoutLength)),
1015         (18, issuer: (String, WithoutLength)),
1016         (20, quantity_max: (u64, HighZeroBytesDroppedBigSize)),
1017         (OFFER_NODE_ID_TYPE, node_id: PublicKey),
1018 });
1019
1020 impl Bech32Encode for Offer {
1021         const BECH32_HRP: &'static str = "lno";
1022 }
1023
1024 impl FromStr for Offer {
1025         type Err = Bolt12ParseError;
1026
1027         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
1028                 Self::from_bech32_str(s)
1029         }
1030 }
1031
1032 impl TryFrom<Vec<u8>> for Offer {
1033         type Error = Bolt12ParseError;
1034
1035         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
1036                 let offer = ParsedMessage::<OfferTlvStream>::try_from(bytes)?;
1037                 let ParsedMessage { bytes, tlv_stream } = offer;
1038                 let contents = OfferContents::try_from(tlv_stream)?;
1039                 let id = OfferId::from_valid_offer_tlv_stream(&bytes);
1040
1041                 Ok(Offer { bytes, contents, id })
1042         }
1043 }
1044
1045 impl TryFrom<OfferTlvStream> for OfferContents {
1046         type Error = Bolt12SemanticError;
1047
1048         fn try_from(tlv_stream: OfferTlvStream) -> Result<Self, Self::Error> {
1049                 let OfferTlvStream {
1050                         chains, metadata, currency, amount, description, features, absolute_expiry, paths,
1051                         issuer, quantity_max, node_id,
1052                 } = tlv_stream;
1053
1054                 let metadata = metadata.map(|metadata| Metadata::Bytes(metadata));
1055
1056                 let amount = match (currency, amount) {
1057                         (None, None) => None,
1058                         (None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
1059                                 return Err(Bolt12SemanticError::InvalidAmount);
1060                         },
1061                         (None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
1062                         (Some(_), None) => return Err(Bolt12SemanticError::MissingAmount),
1063                         (Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),
1064                 };
1065
1066                 let description = match description {
1067                         None => return Err(Bolt12SemanticError::MissingDescription),
1068                         Some(description) => description,
1069                 };
1070
1071                 let features = features.unwrap_or_else(OfferFeatures::empty);
1072
1073                 let absolute_expiry = absolute_expiry
1074                         .map(|seconds_from_epoch| Duration::from_secs(seconds_from_epoch));
1075
1076                 let supported_quantity = match quantity_max {
1077                         None => Quantity::One,
1078                         Some(0) => Quantity::Unbounded,
1079                         Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
1080                 };
1081
1082                 let signing_pubkey = match node_id {
1083                         None => return Err(Bolt12SemanticError::MissingSigningPubkey),
1084                         Some(node_id) => node_id,
1085                 };
1086
1087                 Ok(OfferContents {
1088                         chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
1089                         supported_quantity, signing_pubkey,
1090                 })
1091         }
1092 }
1093
1094 impl core::fmt::Display for Offer {
1095         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
1096                 self.fmt_bech32_str(f)
1097         }
1098 }
1099
1100 #[cfg(test)]
1101 mod tests {
1102         use super::{Amount, Offer, OfferTlvStreamRef, Quantity};
1103         #[cfg(not(c_bindings))]
1104         use {
1105                 super::OfferBuilder,
1106         };
1107         #[cfg(c_bindings)]
1108         use {
1109                 super::OfferWithExplicitMetadataBuilder as OfferBuilder,
1110         };
1111
1112         use bitcoin::blockdata::constants::ChainHash;
1113         use bitcoin::network::constants::Network;
1114         use bitcoin::secp256k1::Secp256k1;
1115         use core::num::NonZeroU64;
1116         use core::time::Duration;
1117         use crate::blinded_path::{BlindedHop, BlindedPath, IntroductionNode};
1118         use crate::sign::KeyMaterial;
1119         use crate::ln::features::OfferFeatures;
1120         use crate::ln::inbound_payment::ExpandedKey;
1121         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
1122         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
1123         use crate::offers::test_utils::*;
1124         use crate::util::ser::{BigSize, Writeable};
1125         use crate::util::string::PrintableString;
1126
1127         #[test]
1128         fn builds_offer_with_defaults() {
1129                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1130
1131                 let mut buffer = Vec::new();
1132                 offer.write(&mut buffer).unwrap();
1133
1134                 assert_eq!(offer.bytes, buffer.as_slice());
1135                 assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
1136                 assert!(offer.supports_chain(ChainHash::using_genesis_block(Network::Bitcoin)));
1137                 assert_eq!(offer.metadata(), None);
1138                 assert_eq!(offer.amount(), None);
1139                 assert_eq!(offer.description(), PrintableString("foo"));
1140                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1141                 assert_eq!(offer.absolute_expiry(), None);
1142                 #[cfg(feature = "std")]
1143                 assert!(!offer.is_expired());
1144                 assert_eq!(offer.paths(), &[]);
1145                 assert_eq!(offer.issuer(), None);
1146                 assert_eq!(offer.supported_quantity(), Quantity::One);
1147                 assert_eq!(offer.signing_pubkey(), pubkey(42));
1148
1149                 assert_eq!(
1150                         offer.as_tlv_stream(),
1151                         OfferTlvStreamRef {
1152                                 chains: None,
1153                                 metadata: None,
1154                                 currency: None,
1155                                 amount: None,
1156                                 description: Some(&String::from("foo")),
1157                                 features: None,
1158                                 absolute_expiry: None,
1159                                 paths: None,
1160                                 issuer: None,
1161                                 quantity_max: None,
1162                                 node_id: Some(&pubkey(42)),
1163                         },
1164                 );
1165
1166                 if let Err(e) = Offer::try_from(buffer) {
1167                         panic!("error parsing offer: {:?}", e);
1168                 }
1169         }
1170
1171         #[test]
1172         fn builds_offer_with_chains() {
1173                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
1174                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
1175
1176                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1177                         .chain(Network::Bitcoin)
1178                         .build()
1179                         .unwrap();
1180                 assert!(offer.supports_chain(mainnet));
1181                 assert_eq!(offer.chains(), vec![mainnet]);
1182                 assert_eq!(offer.as_tlv_stream().chains, None);
1183
1184                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1185                         .chain(Network::Testnet)
1186                         .build()
1187                         .unwrap();
1188                 assert!(offer.supports_chain(testnet));
1189                 assert_eq!(offer.chains(), vec![testnet]);
1190                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1191
1192                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1193                         .chain(Network::Testnet)
1194                         .chain(Network::Testnet)
1195                         .build()
1196                         .unwrap();
1197                 assert!(offer.supports_chain(testnet));
1198                 assert_eq!(offer.chains(), vec![testnet]);
1199                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1200
1201                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1202                         .chain(Network::Bitcoin)
1203                         .chain(Network::Testnet)
1204                         .build()
1205                         .unwrap();
1206                 assert!(offer.supports_chain(mainnet));
1207                 assert!(offer.supports_chain(testnet));
1208                 assert_eq!(offer.chains(), vec![mainnet, testnet]);
1209                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet]));
1210         }
1211
1212         #[test]
1213         fn builds_offer_with_metadata() {
1214                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1215                         .metadata(vec![42; 32]).unwrap()
1216                         .build()
1217                         .unwrap();
1218                 assert_eq!(offer.metadata(), Some(&vec![42; 32]));
1219                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![42; 32]));
1220
1221                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1222                         .metadata(vec![42; 32]).unwrap()
1223                         .metadata(vec![43; 32]).unwrap()
1224                         .build()
1225                         .unwrap();
1226                 assert_eq!(offer.metadata(), Some(&vec![43; 32]));
1227                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![43; 32]));
1228         }
1229
1230         #[test]
1231         fn builds_offer_with_metadata_derived() {
1232                 let desc = "foo".to_string();
1233                 let node_id = recipient_pubkey();
1234                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1235                 let entropy = FixedEntropy {};
1236                 let secp_ctx = Secp256k1::new();
1237
1238                 #[cfg(c_bindings)]
1239                 use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
1240                 let offer = OfferBuilder
1241                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1242                         .amount_msats(1000)
1243                         .build().unwrap();
1244                 assert_eq!(offer.signing_pubkey(), node_id);
1245
1246                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1247                         .build().unwrap()
1248                         .sign(payer_sign).unwrap();
1249                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1250
1251                 // Fails verification with altered offer field
1252                 let mut tlv_stream = offer.as_tlv_stream();
1253                 tlv_stream.amount = Some(100);
1254
1255                 let mut encoded_offer = Vec::new();
1256                 tlv_stream.write(&mut encoded_offer).unwrap();
1257
1258                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1259                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1260                         .build().unwrap()
1261                         .sign(payer_sign).unwrap();
1262                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1263
1264                 // Fails verification with altered metadata
1265                 let mut tlv_stream = offer.as_tlv_stream();
1266                 let metadata = tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1267                 tlv_stream.metadata = Some(&metadata);
1268
1269                 let mut encoded_offer = Vec::new();
1270                 tlv_stream.write(&mut encoded_offer).unwrap();
1271
1272                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1273                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1274                         .build().unwrap()
1275                         .sign(payer_sign).unwrap();
1276                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1277         }
1278
1279         #[test]
1280         fn builds_offer_with_derived_signing_pubkey() {
1281                 let desc = "foo".to_string();
1282                 let node_id = recipient_pubkey();
1283                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1284                 let entropy = FixedEntropy {};
1285                 let secp_ctx = Secp256k1::new();
1286
1287                 let blinded_path = BlindedPath {
1288                         introduction_node: IntroductionNode::NodeId(pubkey(40)),
1289                         blinding_point: pubkey(41),
1290                         blinded_hops: vec![
1291                                 BlindedHop { blinded_node_id: pubkey(42), encrypted_payload: vec![0; 43] },
1292                                 BlindedHop { blinded_node_id: node_id, encrypted_payload: vec![0; 44] },
1293                         ],
1294                 };
1295
1296                 #[cfg(c_bindings)]
1297                 use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
1298                 let offer = OfferBuilder
1299                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1300                         .amount_msats(1000)
1301                         .path(blinded_path)
1302                         .build().unwrap();
1303                 assert_ne!(offer.signing_pubkey(), node_id);
1304
1305                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1306                         .build().unwrap()
1307                         .sign(payer_sign).unwrap();
1308                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1309
1310                 // Fails verification with altered offer field
1311                 let mut tlv_stream = offer.as_tlv_stream();
1312                 tlv_stream.amount = Some(100);
1313
1314                 let mut encoded_offer = Vec::new();
1315                 tlv_stream.write(&mut encoded_offer).unwrap();
1316
1317                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1318                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1319                         .build().unwrap()
1320                         .sign(payer_sign).unwrap();
1321                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1322
1323                 // Fails verification with altered signing pubkey
1324                 let mut tlv_stream = offer.as_tlv_stream();
1325                 let signing_pubkey = pubkey(1);
1326                 tlv_stream.node_id = Some(&signing_pubkey);
1327
1328                 let mut encoded_offer = Vec::new();
1329                 tlv_stream.write(&mut encoded_offer).unwrap();
1330
1331                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1332                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1333                         .build().unwrap()
1334                         .sign(payer_sign).unwrap();
1335                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1336         }
1337
1338         #[test]
1339         fn builds_offer_with_amount() {
1340                 let bitcoin_amount = Amount::Bitcoin { amount_msats: 1000 };
1341                 let currency_amount = Amount::Currency { iso4217_code: *b"USD", amount: 10 };
1342
1343                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1344                         .amount_msats(1000)
1345                         .build()
1346                         .unwrap();
1347                 let tlv_stream = offer.as_tlv_stream();
1348                 assert_eq!(offer.amount(), Some(&bitcoin_amount));
1349                 assert_eq!(tlv_stream.amount, Some(1000));
1350                 assert_eq!(tlv_stream.currency, None);
1351
1352                 #[cfg(not(c_bindings))]
1353                 let builder = OfferBuilder::new("foo".into(), pubkey(42))
1354                         .amount(currency_amount.clone());
1355                 #[cfg(c_bindings)]
1356                 let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
1357                 #[cfg(c_bindings)]
1358                 builder.amount(currency_amount.clone());
1359                 let tlv_stream = builder.offer.as_tlv_stream();
1360                 assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
1361                 assert_eq!(tlv_stream.amount, Some(10));
1362                 assert_eq!(tlv_stream.currency, Some(b"USD"));
1363                 match builder.build() {
1364                         Ok(_) => panic!("expected error"),
1365                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedCurrency),
1366                 }
1367
1368                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1369                         .amount(currency_amount.clone())
1370                         .amount(bitcoin_amount.clone())
1371                         .build()
1372                         .unwrap();
1373                 let tlv_stream = offer.as_tlv_stream();
1374                 assert_eq!(tlv_stream.amount, Some(1000));
1375                 assert_eq!(tlv_stream.currency, None);
1376
1377                 let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
1378                 match OfferBuilder::new("foo".into(), pubkey(42)).amount(invalid_amount).build() {
1379                         Ok(_) => panic!("expected error"),
1380                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1381                 }
1382         }
1383
1384         #[test]
1385         fn builds_offer_with_features() {
1386                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1387                         .features_unchecked(OfferFeatures::unknown())
1388                         .build()
1389                         .unwrap();
1390                 assert_eq!(offer.offer_features(), &OfferFeatures::unknown());
1391                 assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
1392
1393                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1394                         .features_unchecked(OfferFeatures::unknown())
1395                         .features_unchecked(OfferFeatures::empty())
1396                         .build()
1397                         .unwrap();
1398                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1399                 assert_eq!(offer.as_tlv_stream().features, None);
1400         }
1401
1402         #[test]
1403         fn builds_offer_with_absolute_expiry() {
1404                 let future_expiry = Duration::from_secs(u64::max_value());
1405                 let past_expiry = Duration::from_secs(0);
1406                 let now = future_expiry - Duration::from_secs(1_000);
1407
1408                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1409                         .absolute_expiry(future_expiry)
1410                         .build()
1411                         .unwrap();
1412                 #[cfg(feature = "std")]
1413                 assert!(!offer.is_expired());
1414                 assert!(!offer.is_expired_no_std(now));
1415                 assert_eq!(offer.absolute_expiry(), Some(future_expiry));
1416                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
1417
1418                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1419                         .absolute_expiry(future_expiry)
1420                         .absolute_expiry(past_expiry)
1421                         .build()
1422                         .unwrap();
1423                 #[cfg(feature = "std")]
1424                 assert!(offer.is_expired());
1425                 assert!(offer.is_expired_no_std(now));
1426                 assert_eq!(offer.absolute_expiry(), Some(past_expiry));
1427                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
1428         }
1429
1430         #[test]
1431         fn builds_offer_with_paths() {
1432                 let paths = vec![
1433                         BlindedPath {
1434                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1435                                 blinding_point: pubkey(41),
1436                                 blinded_hops: vec![
1437                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1438                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1439                                 ],
1440                         },
1441                         BlindedPath {
1442                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1443                                 blinding_point: pubkey(41),
1444                                 blinded_hops: vec![
1445                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1446                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1447                                 ],
1448                         },
1449                 ];
1450
1451                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1452                         .path(paths[0].clone())
1453                         .path(paths[1].clone())
1454                         .build()
1455                         .unwrap();
1456                 let tlv_stream = offer.as_tlv_stream();
1457                 assert_eq!(offer.paths(), paths.as_slice());
1458                 assert_eq!(offer.signing_pubkey(), pubkey(42));
1459                 assert_ne!(pubkey(42), pubkey(44));
1460                 assert_eq!(tlv_stream.paths, Some(&paths));
1461                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
1462         }
1463
1464         #[test]
1465         fn builds_offer_with_issuer() {
1466                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1467                         .issuer("bar".into())
1468                         .build()
1469                         .unwrap();
1470                 assert_eq!(offer.issuer(), Some(PrintableString("bar")));
1471                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("bar")));
1472
1473                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1474                         .issuer("bar".into())
1475                         .issuer("baz".into())
1476                         .build()
1477                         .unwrap();
1478                 assert_eq!(offer.issuer(), Some(PrintableString("baz")));
1479                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("baz")));
1480         }
1481
1482         #[test]
1483         fn builds_offer_with_supported_quantity() {
1484                 let one = NonZeroU64::new(1).unwrap();
1485                 let ten = NonZeroU64::new(10).unwrap();
1486
1487                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1488                         .supported_quantity(Quantity::One)
1489                         .build()
1490                         .unwrap();
1491                 let tlv_stream = offer.as_tlv_stream();
1492                 assert_eq!(offer.supported_quantity(), Quantity::One);
1493                 assert_eq!(tlv_stream.quantity_max, None);
1494
1495                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1496                         .supported_quantity(Quantity::Unbounded)
1497                         .build()
1498                         .unwrap();
1499                 let tlv_stream = offer.as_tlv_stream();
1500                 assert_eq!(offer.supported_quantity(), Quantity::Unbounded);
1501                 assert_eq!(tlv_stream.quantity_max, Some(0));
1502
1503                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1504                         .supported_quantity(Quantity::Bounded(ten))
1505                         .build()
1506                         .unwrap();
1507                 let tlv_stream = offer.as_tlv_stream();
1508                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(ten));
1509                 assert_eq!(tlv_stream.quantity_max, Some(10));
1510
1511                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1512                         .supported_quantity(Quantity::Bounded(one))
1513                         .build()
1514                         .unwrap();
1515                 let tlv_stream = offer.as_tlv_stream();
1516                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(one));
1517                 assert_eq!(tlv_stream.quantity_max, Some(1));
1518
1519                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1520                         .supported_quantity(Quantity::Bounded(ten))
1521                         .supported_quantity(Quantity::One)
1522                         .build()
1523                         .unwrap();
1524                 let tlv_stream = offer.as_tlv_stream();
1525                 assert_eq!(offer.supported_quantity(), Quantity::One);
1526                 assert_eq!(tlv_stream.quantity_max, None);
1527         }
1528
1529         #[test]
1530         fn fails_requesting_invoice_with_unknown_required_features() {
1531                 match OfferBuilder::new("foo".into(), pubkey(42))
1532                         .features_unchecked(OfferFeatures::unknown())
1533                         .build().unwrap()
1534                         .request_invoice(vec![1; 32], pubkey(43))
1535                 {
1536                         Ok(_) => panic!("expected error"),
1537                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1538                 }
1539         }
1540
1541         #[test]
1542         fn parses_offer_with_chains() {
1543                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1544                         .chain(Network::Bitcoin)
1545                         .chain(Network::Testnet)
1546                         .build()
1547                         .unwrap();
1548                 if let Err(e) = offer.to_string().parse::<Offer>() {
1549                         panic!("error parsing offer: {:?}", e);
1550                 }
1551         }
1552
1553         #[test]
1554         fn parses_offer_with_amount() {
1555                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1556                         .amount(Amount::Bitcoin { amount_msats: 1000 })
1557                         .build()
1558                         .unwrap();
1559                 if let Err(e) = offer.to_string().parse::<Offer>() {
1560                         panic!("error parsing offer: {:?}", e);
1561                 }
1562
1563                 let mut tlv_stream = offer.as_tlv_stream();
1564                 tlv_stream.amount = Some(1000);
1565                 tlv_stream.currency = Some(b"USD");
1566
1567                 let mut encoded_offer = Vec::new();
1568                 tlv_stream.write(&mut encoded_offer).unwrap();
1569
1570                 if let Err(e) = Offer::try_from(encoded_offer) {
1571                         panic!("error parsing offer: {:?}", e);
1572                 }
1573
1574                 let mut tlv_stream = offer.as_tlv_stream();
1575                 tlv_stream.amount = None;
1576                 tlv_stream.currency = Some(b"USD");
1577
1578                 let mut encoded_offer = Vec::new();
1579                 tlv_stream.write(&mut encoded_offer).unwrap();
1580
1581                 match Offer::try_from(encoded_offer) {
1582                         Ok(_) => panic!("expected error"),
1583                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1584                 }
1585
1586                 let mut tlv_stream = offer.as_tlv_stream();
1587                 tlv_stream.amount = Some(MAX_VALUE_MSAT + 1);
1588                 tlv_stream.currency = None;
1589
1590                 let mut encoded_offer = Vec::new();
1591                 tlv_stream.write(&mut encoded_offer).unwrap();
1592
1593                 match Offer::try_from(encoded_offer) {
1594                         Ok(_) => panic!("expected error"),
1595                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1596                 }
1597         }
1598
1599         #[test]
1600         fn parses_offer_with_description() {
1601                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1602                 if let Err(e) = offer.to_string().parse::<Offer>() {
1603                         panic!("error parsing offer: {:?}", e);
1604                 }
1605
1606                 let mut tlv_stream = offer.as_tlv_stream();
1607                 tlv_stream.description = None;
1608
1609                 let mut encoded_offer = Vec::new();
1610                 tlv_stream.write(&mut encoded_offer).unwrap();
1611
1612                 match Offer::try_from(encoded_offer) {
1613                         Ok(_) => panic!("expected error"),
1614                         Err(e) => {
1615                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription));
1616                         },
1617                 }
1618         }
1619
1620         #[test]
1621         fn parses_offer_with_paths() {
1622                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1623                         .path(BlindedPath {
1624                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1625                                 blinding_point: pubkey(41),
1626                                 blinded_hops: vec![
1627                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1628                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1629                                 ],
1630                         })
1631                         .path(BlindedPath {
1632                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1633                                 blinding_point: pubkey(41),
1634                                 blinded_hops: vec![
1635                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1636                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1637                                 ],
1638                         })
1639                         .build()
1640                         .unwrap();
1641                 if let Err(e) = offer.to_string().parse::<Offer>() {
1642                         panic!("error parsing offer: {:?}", e);
1643                 }
1644
1645                 let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
1646                 builder.offer.paths = Some(vec![]);
1647
1648                 let offer = builder.build().unwrap();
1649                 if let Err(e) = offer.to_string().parse::<Offer>() {
1650                         panic!("error parsing offer: {:?}", e);
1651                 }
1652         }
1653
1654         #[test]
1655         fn parses_offer_with_quantity() {
1656                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1657                         .supported_quantity(Quantity::One)
1658                         .build()
1659                         .unwrap();
1660                 if let Err(e) = offer.to_string().parse::<Offer>() {
1661                         panic!("error parsing offer: {:?}", e);
1662                 }
1663
1664                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1665                         .supported_quantity(Quantity::Unbounded)
1666                         .build()
1667                         .unwrap();
1668                 if let Err(e) = offer.to_string().parse::<Offer>() {
1669                         panic!("error parsing offer: {:?}", e);
1670                 }
1671
1672                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1673                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(10).unwrap()))
1674                         .build()
1675                         .unwrap();
1676                 if let Err(e) = offer.to_string().parse::<Offer>() {
1677                         panic!("error parsing offer: {:?}", e);
1678                 }
1679
1680                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1681                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(1).unwrap()))
1682                         .build()
1683                         .unwrap();
1684                 if let Err(e) = offer.to_string().parse::<Offer>() {
1685                         panic!("error parsing offer: {:?}", e);
1686                 }
1687         }
1688
1689         #[test]
1690         fn parses_offer_with_node_id() {
1691                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1692                 if let Err(e) = offer.to_string().parse::<Offer>() {
1693                         panic!("error parsing offer: {:?}", e);
1694                 }
1695
1696                 let mut tlv_stream = offer.as_tlv_stream();
1697                 tlv_stream.node_id = None;
1698
1699                 let mut encoded_offer = Vec::new();
1700                 tlv_stream.write(&mut encoded_offer).unwrap();
1701
1702                 match Offer::try_from(encoded_offer) {
1703                         Ok(_) => panic!("expected error"),
1704                         Err(e) => {
1705                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1706                         },
1707                 }
1708         }
1709
1710         #[test]
1711         fn fails_parsing_offer_with_extra_tlv_records() {
1712                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1713
1714                 let mut encoded_offer = Vec::new();
1715                 offer.write(&mut encoded_offer).unwrap();
1716                 BigSize(80).write(&mut encoded_offer).unwrap();
1717                 BigSize(32).write(&mut encoded_offer).unwrap();
1718                 [42u8; 32].write(&mut encoded_offer).unwrap();
1719
1720                 match Offer::try_from(encoded_offer) {
1721                         Ok(_) => panic!("expected error"),
1722                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1723                 }
1724         }
1725 }
1726
1727 #[cfg(test)]
1728 mod bolt12_tests {
1729         use super::{Bolt12ParseError, Bolt12SemanticError, Offer};
1730         use crate::ln::msgs::DecodeError;
1731
1732         #[test]
1733         fn parses_bech32_encoded_offers() {
1734                 let offers = [
1735                         // Minimal bolt12 offer
1736                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1737
1738                         // for testnet
1739                         "lno1qgsyxjtl6luzd9t3pr62xr7eemp6awnejusgf6gw45q75vcfqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1740
1741                         // for bitcoin (redundant)
1742                         "lno1qgsxlc5vp2m0rvmjcxn2y34wv0m5lyc7sdj7zksgn35dvxgqqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1743
1744                         // for bitcoin or liquidv1
1745                         "lno1qfqpge38tqmzyrdjj3x2qkdr5y80dlfw56ztq6yd9sme995g3gsxqqm0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq9qc4r9wd6zqan9vd6x7unnzcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1746
1747                         // with metadata
1748                         "lno1qsgqqqqqqqqqqqqqqqqqqqqqqqqqqzsv23jhxapqwejkxar0wfe3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1749
1750                         // with amount
1751                         "lno1pqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1752
1753                         // with currency
1754                         "lno1qcp4256ypqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1755
1756                         // with expiry
1757                         "lno1pgx9getnwss8vetrw3hhyucwq3ay997czcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1758
1759                         // with issuer
1760                         "lno1pgx9getnwss8vetrw3hhyucjy358garswvaz7tmzdak8gvfj9ehhyeeqgf85c4p3xgsxjmnyw4ehgunfv4e3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1761
1762                         // with quantity
1763                         "lno1pgx9getnwss8vetrw3hhyuc5qyz3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1764
1765                         // with unlimited (or unknown) quantity
1766                         "lno1pgx9getnwss8vetrw3hhyuc5qqtzzqhwcuj966ma9n9nqwqtl032xeyv6755yeflt235pmww58egx6rxry",
1767
1768                         // with single quantity (weird but valid)
1769                         "lno1pgx9getnwss8vetrw3hhyuc5qyq3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1770
1771                         // with feature
1772                         "lno1pgx9getnwss8vetrw3hhyucvp5yqqqqqqqqqqqqqqqqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1773
1774                         // with blinded path via Bob (0x424242...), blinding 020202...
1775                         "lno1pgx9getnwss8vetrw3hhyucs5ypjgef743p5fzqq9nqxh0ah7y87rzv3ud0eleps9kl2d5348hq2k8qzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgqpqqqqqqqqqqqqqqqqqqqqqqqqqqqzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqqzq3zyg3zyg3zyg3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1776
1777                         // ... and with second blinded path via Carol (0x434343...), blinding 020202...
1778                         "lno1pgx9getnwss8vetrw3hhyucsl5q5yqeyv5l2cs6y3qqzesrth7mlzrlp3xg7xhulusczm04x6g6nms9trspqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqqsqqqqqqqqqqqqqqqqqqqqqqqqqqpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsqpqg3zyg3zyg3zygz0uc7h32x9s0aecdhxlk075kn046aafpuuyw8f5j652t3vha2yqrsyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsqzqqqqqqqqqqqqqqqqqqqqqqqqqqqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqqyzyg3zyg3zyg3zzcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1779
1780                         // unknown odd field
1781                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxfppf5x2mrvdamk7unvvs",
1782                 ];
1783                 for encoded_offer in &offers {
1784                         if let Err(e) = encoded_offer.parse::<Offer>() {
1785                                 panic!("Invalid offer ({:?}): {}", e, encoded_offer);
1786                         }
1787                 }
1788         }
1789
1790         #[test]
1791         fn fails_parsing_bech32_encoded_offers() {
1792                 // Malformed: fields out of order
1793                 assert_eq!(
1794                         "lno1zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszpgz5znzfgdzs".parse::<Offer>(),
1795                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1796                 );
1797
1798                 // Malformed: unknown even TLV type 78
1799                 assert_eq!(
1800                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpysgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1801                         Err(Bolt12ParseError::Decode(DecodeError::UnknownRequiredFeature)),
1802                 );
1803
1804                 // Malformed: empty
1805                 assert_eq!(
1806                         "lno1".parse::<Offer>(),
1807                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
1808                 );
1809
1810                 // Malformed: truncated at type
1811                 assert_eq!(
1812                         "lno1pg".parse::<Offer>(),
1813                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1814                 );
1815
1816                 // Malformed: truncated in length
1817                 assert_eq!(
1818                         "lno1pt7s".parse::<Offer>(),
1819                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1820                 );
1821
1822                 // Malformed: truncated after length
1823                 assert_eq!(
1824                         "lno1pgpq".parse::<Offer>(),
1825                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1826                 );
1827
1828                 // Malformed: truncated in description
1829                 assert_eq!(
1830                         "lno1pgpyz".parse::<Offer>(),
1831                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1832                 );
1833
1834                 // Malformed: invalid offer_chains length
1835                 assert_eq!(
1836                         "lno1qgqszzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1837                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1838                 );
1839
1840                 // Malformed: truncated currency UTF-8
1841                 assert_eq!(
1842                         "lno1qcqcqzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1843                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1844                 );
1845
1846                 // Malformed: invalid currency UTF-8
1847                 assert_eq!(
1848                         "lno1qcpgqsg2q4q5cj2rg5tzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1849                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1850                 );
1851
1852                 // Malformed: truncated description UTF-8
1853                 assert_eq!(
1854                         "lno1pgqcq93pqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqy".parse::<Offer>(),
1855                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1856                 );
1857
1858                 // Malformed: invalid description UTF-8
1859                 assert_eq!(
1860                         "lno1pgpgqsgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1861                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1862                 );
1863
1864                 // Malformed: truncated offer_paths
1865                 assert_eq!(
1866                         "lno1pgz5znzfgdz3qqgpzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1867                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1868                 );
1869
1870                 // Malformed: zero num_hops in blinded_path
1871                 assert_eq!(
1872                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1873                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1874                 );
1875
1876                 // Malformed: truncated onionmsg_hop in blinded_path
1877                 assert_eq!(
1878                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1879                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1880                 );
1881
1882                 // Malformed: bad first_node_id in blinded_path
1883                 assert_eq!(
1884                         "lno1pgz5znzfgdz3qqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1885                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1886                 );
1887
1888                 // Malformed: bad blinding in blinded_path
1889                 assert_eq!(
1890                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcpqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1891                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1892                 );
1893
1894                 // Malformed: bad blinded_node_id in onionmsg_hop
1895                 assert_eq!(
1896                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1897                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1898                 );
1899
1900                 // Malformed: truncated issuer UTF-8
1901                 assert_eq!(
1902                         "lno1pgz5znzfgdz3yqvqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1903                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1904                 );
1905
1906                 // Malformed: invalid issuer UTF-8
1907                 assert_eq!(
1908                         "lno1pgz5znzfgdz3yq5qgytzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1909                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1910                 );
1911
1912                 // Malformed: invalid offer_node_id
1913                 assert_eq!(
1914                         "lno1pgz5znzfgdz3vggzqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvps".parse::<Offer>(),
1915                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1916                 );
1917
1918                 // Contains type >= 80
1919                 assert_eq!(
1920                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgp9qgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1921                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1922                 );
1923
1924                 // TODO: Resolved in spec https://github.com/lightning/bolts/pull/798/files#r1334851959
1925                 // Contains unknown feature 22
1926                 assert!(
1927                         "lno1pgx9getnwss8vetrw3hhyucvqdqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg".parse::<Offer>().is_ok()
1928                 );
1929
1930                 // Missing offer_description
1931                 assert_eq!(
1932                         "lno1zcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese".parse::<Offer>(),
1933                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
1934                 );
1935
1936                 // Missing offer_node_id"
1937                 assert_eq!(
1938                         "lno1pgx9getnwss8vetrw3hhyuc".parse::<Offer>(),
1939                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey)),
1940                 );
1941         }
1942 }