_ 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(pubkey)
  47 //!     .description("coffee, large".to_string())
  48 //!     .amount_msats(20_000)
  49 //!     .supported_quantity(Quantity::Unbounded)
  50 //!     .absolute_expiry(expiration.duration_since(SystemTime::UNIX_EPOCH).unwrap())
  51 //!     .issuer("Foo Bar".to_string())
  52 //!     .path(create_blinded_path())
  53 //!     .path(create_another_blinded_path())
  54 //!     .build()?;
  55 //!
  56 //! // Encode as a bech32 string for use in a QR code.
  57 //! let encoded_offer = offer.to_string();
  58 //!
  59 //! // Parse from a bech32 string after scanning from a QR code.
  60 //! let offer = encoded_offer.parse::<Offer>()?;
  61 //!
  62 //! // Encode offer as raw bytes.
  63 //! let mut bytes = Vec::new();
  64 //! offer.write(&mut bytes).unwrap();
  65 //!
  66 //! // Decode raw bytes into an offer.
  67 //! let offer = Offer::try_from(bytes)?;
  68 //! # Ok(())
  69 //! # }
  70 //! ```
  71 //!
  72 //! # Note
  73 //!
  74 //! If constructing an [`Offer`] for use with a [`ChannelManager`], use
  75 //! [`ChannelManager::create_offer_builder`] instead of [`OfferBuilder::new`].
  76 //!
  77 //! [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
  78 //! [`ChannelManager::create_offer_builder`]: crate::ln::channelmanager::ChannelManager::create_offer_builder
  79
  80 use bitcoin::blockdata::constants::ChainHash;
  81 use bitcoin::network::constants::Network;
  82 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, self};
  83 use core::hash::{Hash, Hasher};
  84 use core::num::NonZeroU64;
  85 use core::ops::Deref;
  86 use core::str::FromStr;
  87 use core::time::Duration;
  88 use crate::sign::EntropySource;
  89 use crate::io;
  90 use crate::blinded_path::BlindedPath;
  91 use crate::ln::channelmanager::PaymentId;
  92 use crate::ln::features::OfferFeatures;
  93 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
  94 use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
  95 use crate::offers::merkle::{TaggedHash, TlvStream};
  96 use crate::offers::parse::{Bech32Encode, Bolt12ParseError, Bolt12SemanticError, ParsedMessage};
  97 use crate::offers::signer::{Metadata, MetadataMaterial, self};
  98 use crate::util::ser::{HighZeroBytesDroppedBigSize, Readable, WithoutLength, Writeable, Writer};
  99 use crate::util::string::PrintableString;
 100
 101 #[cfg(not(c_bindings))]
 102 use {
 103         crate::offers::invoice_request::{DerivedPayerId, ExplicitPayerId, InvoiceRequestBuilder},
 104 };
 105 #[cfg(c_bindings)]
 106 use {
 107         crate::offers::invoice_request::{InvoiceRequestWithDerivedPayerIdBuilder, InvoiceRequestWithExplicitPayerIdBuilder},
 108 };
 109
 110 #[allow(unused_imports)]
 111 use crate::prelude::*;
 112
 113 #[cfg(feature = "std")]
 114 use std::time::SystemTime;
 115
 116 pub(super) const IV_BYTES: &[u8; IV_LEN] = b"LDK Offer ~~~~~~";
 117
 118 /// An identifier for an [`Offer`] built using [`DerivedMetadata`].
 119 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 120 pub struct OfferId(pub [u8; 32]);
 121
 122 impl OfferId {
 123         const ID_TAG: &'static str = "LDK Offer ID";
 124
 125         fn from_valid_offer_tlv_stream(bytes: &[u8]) -> Self {
 126                 let tagged_hash = TaggedHash::from_valid_tlv_stream_bytes(Self::ID_TAG, bytes);
 127                 Self(tagged_hash.to_bytes())
 128         }
 129
 130         fn from_valid_invreq_tlv_stream(bytes: &[u8]) -> Self {
 131                 let tlv_stream = TlvStream::new(bytes).range(OFFER_TYPES);
 132                 let tagged_hash = TaggedHash::from_tlv_stream(Self::ID_TAG, tlv_stream);
 133                 Self(tagged_hash.to_bytes())
 134         }
 135 }
 136
 137 impl Writeable for OfferId {
 138         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 139                 self.0.write(w)
 140         }
 141 }
 142
 143 impl Readable for OfferId {
 144         fn read<R: io::Read>(r: &mut R) -> Result<Self, DecodeError> {
 145                 Ok(OfferId(Readable::read(r)?))
 146         }
 147 }
 148
 149 /// Builds an [`Offer`] for the "offer to be paid" flow.
 150 ///
 151 /// See [module-level documentation] for usage.
 152 ///
 153 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 154 ///
 155 /// [module-level documentation]: self
 156 pub struct OfferBuilder<'a, M: MetadataStrategy, T: secp256k1::Signing> {
 157         offer: OfferContents,
 158         metadata_strategy: core::marker::PhantomData<M>,
 159         secp_ctx: Option<&'a Secp256k1<T>>,
 160 }
 161
 162 /// Builds an [`Offer`] for the "offer to be paid" flow.
 163 ///
 164 /// See [module-level documentation] for usage.
 165 ///
 166 /// [module-level documentation]: self
 167 #[cfg(c_bindings)]
 168 #[derive(Clone)]
 169 pub struct OfferWithExplicitMetadataBuilder<'a> {
 170         offer: OfferContents,
 171         metadata_strategy: core::marker::PhantomData<ExplicitMetadata>,
 172         secp_ctx: Option<&'a Secp256k1<secp256k1::All>>,
 173 }
 174
 175 /// Builds an [`Offer`] for the "offer to be paid" flow.
 176 ///
 177 /// See [module-level documentation] for usage.
 178 ///
 179 /// [module-level documentation]: self
 180 #[cfg(c_bindings)]
 181 #[derive(Clone)]
 182 pub struct OfferWithDerivedMetadataBuilder<'a> {
 183         offer: OfferContents,
 184         metadata_strategy: core::marker::PhantomData<DerivedMetadata>,
 185         secp_ctx: Option<&'a Secp256k1<secp256k1::All>>,
 186 }
 187
 188 /// Indicates how [`Offer::metadata`] may be set.
 189 ///
 190 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 191 pub trait MetadataStrategy {}
 192
 193 /// [`Offer::metadata`] may be explicitly set or left empty.
 194 ///
 195 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 196 pub struct ExplicitMetadata {}
 197
 198 /// [`Offer::metadata`] will be derived.
 199 ///
 200 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 201 pub struct DerivedMetadata {}
 202
 203 impl MetadataStrategy for ExplicitMetadata {}
 204
 205 impl MetadataStrategy for DerivedMetadata {}
 206
 207 macro_rules! offer_explicit_metadata_builder_methods { (
 208         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr
 209 ) => {
 210         /// Creates a new builder for an offer using the [`Offer::signing_pubkey`] for signing invoices.
 211         /// The associated secret key must be remembered while the offer is valid.
 212         ///
 213         /// Use a different pubkey per offer to avoid correlating offers.
 214         ///
 215         /// # Note
 216         ///
 217         /// If constructing an [`Offer`] for use with a [`ChannelManager`], use
 218         /// [`ChannelManager::create_offer_builder`] instead of [`OfferBuilder::new`].
 219         ///
 220         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 221         /// [`ChannelManager::create_offer_builder`]: crate::ln::channelmanager::ChannelManager::create_offer_builder
 222         pub fn new(signing_pubkey: PublicKey) -> Self {
 223                 Self {
 224                         offer: OfferContents {
 225                                 chains: None, metadata: None, amount: None, description: None,
 226                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 227                                 supported_quantity: Quantity::One, signing_pubkey: Some(signing_pubkey),
 228                         },
 229                         metadata_strategy: core::marker::PhantomData,
 230                         secp_ctx: None,
 231                 }
 232         }
 233
 234         /// Sets the [`Offer::metadata`] to the given bytes.
 235         ///
 236         /// Successive calls to this method will override the previous setting.
 237         pub fn metadata(mut $self: $self_type, metadata: Vec<u8>) -> Result<$return_type, Bolt12SemanticError> {
 238                 $self.offer.metadata = Some(Metadata::Bytes(metadata));
 239                 Ok($return_value)
 240         }
 241 } }
 242
 243 macro_rules! offer_derived_metadata_builder_methods { ($secp_context: ty) => {
 244         /// Similar to [`OfferBuilder::new`] except, if [`OfferBuilder::path`] is called, the signing
 245         /// pubkey is derived from the given [`ExpandedKey`] and [`EntropySource`]. This provides
 246         /// recipient privacy by using a different signing pubkey for each offer. Otherwise, the
 247         /// provided `node_id` is used for the signing pubkey.
 248         ///
 249         /// Also, sets the metadata when [`OfferBuilder::build`] is called such that it can be used by
 250         /// [`InvoiceRequest::verify`] to determine if the request was produced for the offer given an
 251         /// [`ExpandedKey`].
 252         ///
 253         /// [`InvoiceRequest::verify`]: crate::offers::invoice_request::InvoiceRequest::verify
 254         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 255         pub fn deriving_signing_pubkey<ES: Deref>(
 256                 node_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 257                 secp_ctx: &'a Secp256k1<$secp_context>
 258         ) -> Self where ES::Target: EntropySource {
 259                 let nonce = Nonce::from_entropy_source(entropy_source);
 260                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, None);
 261                 let metadata = Metadata::DerivedSigningPubkey(derivation_material);
 262                 Self {
 263                         offer: OfferContents {
 264                                 chains: None, metadata: Some(metadata), amount: None, description: None,
 265                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 266                                 supported_quantity: Quantity::One, signing_pubkey: Some(node_id),
 267                         },
 268                         metadata_strategy: core::marker::PhantomData,
 269                         secp_ctx: Some(secp_ctx),
 270                 }
 271         }
 272 } }
 273
 274 macro_rules! offer_builder_methods { (
 275         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
 276 ) => {
 277         /// Adds the chain hash of the given [`Network`] to [`Offer::chains`]. If not called,
 278         /// the chain hash of [`Network::Bitcoin`] is assumed to be the only one supported.
 279         ///
 280         /// See [`Offer::chains`] on how this relates to the payment currency.
 281         ///
 282         /// Successive calls to this method will add another chain hash.
 283         pub fn chain($self: $self_type, network: Network) -> $return_type {
 284                 $self.chain_hash(ChainHash::using_genesis_block(network))
 285         }
 286
 287         /// Adds the [`ChainHash`] to [`Offer::chains`]. If not called, the chain hash of
 288         /// [`Network::Bitcoin`] is assumed to be the only one supported.
 289         ///
 290         /// See [`Offer::chains`] on how this relates to the payment currency.
 291         ///
 292         /// Successive calls to this method will add another chain hash.
 293         pub(crate) fn chain_hash($($self_mut)* $self: $self_type, chain: ChainHash) -> $return_type {
 294                 let chains = $self.offer.chains.get_or_insert_with(Vec::new);
 295                 if !chains.contains(&chain) {
 296                         chains.push(chain);
 297                 }
 298
 299                 $return_value
 300         }
 301
 302         /// Sets the [`Offer::amount`] as an [`Amount::Bitcoin`].
 303         ///
 304         /// Successive calls to this method will override the previous setting.
 305         pub fn amount_msats($self: $self_type, amount_msats: u64) -> $return_type {
 306                 $self.amount(Amount::Bitcoin { amount_msats })
 307         }
 308
 309         /// Sets the [`Offer::amount`].
 310         ///
 311         /// Successive calls to this method will override the previous setting.
 312         pub(super) fn amount($($self_mut)* $self: $self_type, amount: Amount) -> $return_type {
 313                 $self.offer.amount = Some(amount);
 314                 $return_value
 315         }
 316
 317         /// Sets the [`Offer::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
 318         /// already passed is valid and can be checked for using [`Offer::is_expired`].
 319         ///
 320         /// Successive calls to this method will override the previous setting.
 321         pub fn absolute_expiry($($self_mut)* $self: $self_type, absolute_expiry: Duration) -> $return_type {
 322                 $self.offer.absolute_expiry = Some(absolute_expiry);
 323                 $return_value
 324         }
 325
 326         /// Sets the [`Offer::description`].
 327         ///
 328         /// Successive calls to this method will override the previous setting.
 329         pub fn description($($self_mut)* $self: $self_type, description: String) -> $return_type {
 330                 $self.offer.description = Some(description);
 331                 $return_value
 332         }
 333
 334         /// Sets the [`Offer::issuer`].
 335         ///
 336         /// Successive calls to this method will override the previous setting.
 337         pub fn issuer($($self_mut)* $self: $self_type, issuer: String) -> $return_type {
 338                 $self.offer.issuer = Some(issuer);
 339                 $return_value
 340         }
 341
 342         /// Adds a blinded path to [`Offer::paths`]. Must include at least one path if only connected by
 343         /// private channels or if [`Offer::signing_pubkey`] is not a public node id.
 344         ///
 345         /// Successive calls to this method will add another blinded path. Caller is responsible for not
 346         /// adding duplicate paths.
 347         pub fn path($($self_mut)* $self: $self_type, path: BlindedPath) -> $return_type {
 348                 $self.offer.paths.get_or_insert_with(Vec::new).push(path);
 349                 $return_value
 350         }
 351
 352         /// Sets the quantity of items for [`Offer::supported_quantity`]. If not called, defaults to
 353         /// [`Quantity::One`].
 354         ///
 355         /// Successive calls to this method will override the previous setting.
 356         pub fn supported_quantity($($self_mut)* $self: $self_type, quantity: Quantity) -> $return_type {
 357                 $self.offer.supported_quantity = quantity;
 358                 $return_value
 359         }
 360
 361         /// Builds an [`Offer`] from the builder's settings.
 362         pub fn build($($self_mut)* $self: $self_type) -> Result<Offer, Bolt12SemanticError> {
 363                 match $self.offer.amount {
 364                         Some(Amount::Bitcoin { amount_msats }) => {
 365                                 if amount_msats > MAX_VALUE_MSAT {
 366                                         return Err(Bolt12SemanticError::InvalidAmount);
 367                                 }
 368                         },
 369                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 370                         None => {},
 371                 }
 372
 373                 if $self.offer.amount.is_some() && $self.offer.description.is_none() {
 374                         $self.offer.description = Some(String::new());
 375                 }
 376
 377                 if let Some(chains) = &$self.offer.chains {
 378                         if chains.len() == 1 && chains[0] == $self.offer.implied_chain() {
 379                                 $self.offer.chains = None;
 380                         }
 381                 }
 382
 383                 Ok($self.build_without_checks())
 384         }
 385
 386         fn build_without_checks($($self_mut)* $self: $self_type) -> Offer {
 387                 // Create the metadata for stateless verification of an InvoiceRequest.
 388                 if let Some(mut metadata) = $self.offer.metadata.take() {
 389                         if metadata.has_derivation_material() {
 390                                 if $self.offer.paths.is_none() {
 391                                         metadata = metadata.without_keys();
 392                                 }
 393
 394                                 let mut tlv_stream = $self.offer.as_tlv_stream();
 395                                 debug_assert_eq!(tlv_stream.metadata, None);
 396                                 tlv_stream.metadata = None;
 397                                 if metadata.derives_recipient_keys() {
 398                                         tlv_stream.node_id = None;
 399                                 }
 400
 401                                 let (derived_metadata, keys) = metadata.derive_from(tlv_stream, $self.secp_ctx);
 402                                 metadata = derived_metadata;
 403                                 if let Some(keys) = keys {
 404                                         $self.offer.signing_pubkey = Some(keys.public_key());
 405                                 }
 406                         }
 407
 408                         $self.offer.metadata = Some(metadata);
 409                 }
 410
 411                 let mut bytes = Vec::new();
 412                 $self.offer.write(&mut bytes).unwrap();
 413
 414                 let id = OfferId::from_valid_offer_tlv_stream(&bytes);
 415
 416                 Offer {
 417                         bytes,
 418                         #[cfg(not(c_bindings))]
 419                         contents: $self.offer,
 420                         #[cfg(c_bindings)]
 421                         contents: $self.offer.clone(),
 422                         id,
 423                 }
 424         }
 425 } }
 426
 427 #[cfg(test)]
 428 macro_rules! offer_builder_test_methods { (
 429         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
 430 ) => {
 431         #[cfg_attr(c_bindings, allow(dead_code))]
 432         fn features_unchecked($($self_mut)* $self: $self_type, features: OfferFeatures) -> $return_type {
 433                 $self.offer.features = features;
 434                 $return_value
 435         }
 436
 437         #[cfg_attr(c_bindings, allow(dead_code))]
 438         pub(crate) fn clear_chains($($self_mut)* $self: $self_type) -> $return_type {
 439                 $self.offer.chains = None;
 440                 $return_value
 441         }
 442
 443         #[cfg_attr(c_bindings, allow(dead_code))]
 444         pub(crate) fn clear_paths($($self_mut)* $self: $self_type) -> $return_type {
 445                 $self.offer.paths = None;
 446                 $return_value
 447         }
 448
 449         #[cfg_attr(c_bindings, allow(dead_code))]
 450         pub(crate) fn clear_signing_pubkey($($self_mut)* $self: $self_type) -> $return_type {
 451                 $self.offer.signing_pubkey = None;
 452                 $return_value
 453         }
 454
 455         #[cfg_attr(c_bindings, allow(dead_code))]
 456         pub(super) fn build_unchecked($self: $self_type) -> Offer {
 457                 $self.build_without_checks()
 458         }
 459 } }
 460
 461 impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
 462         offer_builder_methods!(self, Self, Self, self, mut);
 463
 464         #[cfg(test)]
 465         offer_builder_test_methods!(self, Self, Self, self, mut);
 466 }
 467
 468 impl<'a> OfferBuilder<'a, ExplicitMetadata, secp256k1::SignOnly> {
 469         offer_explicit_metadata_builder_methods!(self, Self, Self, self);
 470 }
 471
 472 impl<'a, T: secp256k1::Signing> OfferBuilder<'a, DerivedMetadata, T> {
 473         offer_derived_metadata_builder_methods!(T);
 474 }
 475
 476 #[cfg(all(c_bindings, not(test)))]
 477 impl<'a> OfferWithExplicitMetadataBuilder<'a> {
 478         offer_explicit_metadata_builder_methods!(self, &mut Self, (), ());
 479         offer_builder_methods!(self, &mut Self, (), ());
 480 }
 481
 482 #[cfg(all(c_bindings, test))]
 483 impl<'a> OfferWithExplicitMetadataBuilder<'a> {
 484         offer_explicit_metadata_builder_methods!(self, &mut Self, &mut Self, self);
 485         offer_builder_methods!(self, &mut Self, &mut Self, self);
 486         offer_builder_test_methods!(self, &mut Self, &mut Self, self);
 487 }
 488
 489 #[cfg(all(c_bindings, not(test)))]
 490 impl<'a> OfferWithDerivedMetadataBuilder<'a> {
 491         offer_derived_metadata_builder_methods!(secp256k1::All);
 492         offer_builder_methods!(self, &mut Self, (), ());
 493 }
 494
 495 #[cfg(all(c_bindings, test))]
 496 impl<'a> OfferWithDerivedMetadataBuilder<'a> {
 497         offer_derived_metadata_builder_methods!(secp256k1::All);
 498         offer_builder_methods!(self, &mut Self, &mut Self, self);
 499         offer_builder_test_methods!(self, &mut Self, &mut Self, self);
 500 }
 501
 502 #[cfg(c_bindings)]
 503 impl<'a> From<OfferBuilder<'a, DerivedMetadata, secp256k1::All>>
 504 for OfferWithDerivedMetadataBuilder<'a> {
 505         fn from(builder: OfferBuilder<'a, DerivedMetadata, secp256k1::All>) -> Self {
 506                 let OfferBuilder { offer, metadata_strategy, secp_ctx } = builder;
 507
 508                 Self { offer, metadata_strategy, secp_ctx }
 509         }
 510 }
 511
 512 #[cfg(c_bindings)]
 513 impl<'a> From<OfferWithDerivedMetadataBuilder<'a>>
 514 for OfferBuilder<'a, DerivedMetadata, secp256k1::All> {
 515         fn from(builder: OfferWithDerivedMetadataBuilder<'a>) -> Self {
 516                 let OfferWithDerivedMetadataBuilder { offer, metadata_strategy, secp_ctx } = builder;
 517
 518                 Self { offer, metadata_strategy, secp_ctx }
 519         }
 520 }
 521
 522 /// An `Offer` is a potentially long-lived proposal for payment of a good or service.
 523 ///
 524 /// An offer is a precursor to an [`InvoiceRequest`]. A merchant publishes an offer from which a
 525 /// customer may request an [`Bolt12Invoice`] for a specific quantity and using an amount sufficient
 526 /// to cover that quantity (i.e., at least `quantity * amount`). See [`Offer::amount`].
 527 ///
 528 /// Offers may be denominated in currency other than bitcoin but are ultimately paid using the
 529 /// latter.
 530 ///
 531 /// Through the use of [`BlindedPath`]s, offers provide recipient privacy.
 532 ///
 533 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 534 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 535 #[derive(Clone, Debug)]
 536 pub struct Offer {
 537         // The serialized offer. Needed when creating an `InvoiceRequest` if the offer contains unknown
 538         // fields.
 539         pub(super) bytes: Vec<u8>,
 540         pub(super) contents: OfferContents,
 541         id: OfferId,
 542 }
 543
 544 /// The contents of an [`Offer`], which may be shared with an [`InvoiceRequest`] or a
 545 /// [`Bolt12Invoice`].
 546 ///
 547 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 548 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 549 #[derive(Clone, Debug)]
 550 #[cfg_attr(test, derive(PartialEq))]
 551 pub(super) struct OfferContents {
 552         chains: Option<Vec<ChainHash>>,
 553         metadata: Option<Metadata>,
 554         amount: Option<Amount>,
 555         description: Option<String>,
 556         features: OfferFeatures,
 557         absolute_expiry: Option<Duration>,
 558         issuer: Option<String>,
 559         paths: Option<Vec<BlindedPath>>,
 560         supported_quantity: Quantity,
 561         signing_pubkey: Option<PublicKey>,
 562 }
 563
 564 macro_rules! offer_accessors { ($self: ident, $contents: expr) => {
 565         // TODO: Return a slice once ChainHash has constants.
 566         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1283
 567         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1286
 568         /// The chains that may be used when paying a requested invoice (e.g., bitcoin mainnet).
 569         /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats)
 570         /// for the selected chain.
 571         pub fn chains(&$self) -> Vec<bitcoin::blockdata::constants::ChainHash> {
 572                 $contents.chains()
 573         }
 574
 575         // TODO: Link to corresponding method in `InvoiceRequest`.
 576         /// Opaque bytes set by the originator. Useful for authentication and validating fields since it
 577         /// is reflected in `invoice_request` messages along with all the other fields from the `offer`.
 578         pub fn metadata(&$self) -> Option<&Vec<u8>> {
 579                 $contents.metadata()
 580         }
 581
 582         /// The minimum amount required for a successful payment of a single item.
 583         pub fn amount(&$self) -> Option<$crate::offers::offer::Amount> {
 584                 $contents.amount()
 585         }
 586
 587         /// A complete description of the purpose of the payment. Intended to be displayed to the user
 588         /// but with the caveat that it has not been verified in any way.
 589         pub fn description(&$self) -> Option<$crate::util::string::PrintableString> {
 590                 $contents.description()
 591         }
 592
 593         /// Features pertaining to the offer.
 594         pub fn offer_features(&$self) -> &$crate::ln::features::OfferFeatures {
 595                 &$contents.features()
 596         }
 597
 598         /// Duration since the Unix epoch when an invoice should no longer be requested.
 599         ///
 600         /// If `None`, the offer does not expire.
 601         pub fn absolute_expiry(&$self) -> Option<core::time::Duration> {
 602                 $contents.absolute_expiry()
 603         }
 604
 605         /// The issuer of the offer, possibly beginning with `user@domain` or `domain`. Intended to be
 606         /// displayed to the user but with the caveat that it has not been verified in any way.
 607         pub fn issuer(&$self) -> Option<$crate::util::string::PrintableString> {
 608                 $contents.issuer()
 609         }
 610
 611         /// Paths to the recipient originating from publicly reachable nodes. Blinded paths provide
 612         /// recipient privacy by obfuscating its node id.
 613         pub fn paths(&$self) -> &[$crate::blinded_path::BlindedPath] {
 614                 $contents.paths()
 615         }
 616
 617         /// The quantity of items supported.
 618         pub fn supported_quantity(&$self) -> $crate::offers::offer::Quantity {
 619                 $contents.supported_quantity()
 620         }
 621
 622         /// The public key used by the recipient to sign invoices.
 623         pub fn signing_pubkey(&$self) -> Option<bitcoin::secp256k1::PublicKey> {
 624                 $contents.signing_pubkey()
 625         }
 626 } }
 627
 628 impl Offer {
 629         offer_accessors!(self, self.contents);
 630
 631         /// Returns the id of the offer.
 632         pub fn id(&self) -> OfferId {
 633                 self.id
 634         }
 635
 636         pub(super) fn implied_chain(&self) -> ChainHash {
 637                 self.contents.implied_chain()
 638         }
 639
 640         /// Returns whether the given chain is supported by the offer.
 641         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 642                 self.contents.supports_chain(chain)
 643         }
 644
 645         /// Whether the offer has expired.
 646         #[cfg(feature = "std")]
 647         pub fn is_expired(&self) -> bool {
 648                 self.contents.is_expired()
 649         }
 650
 651         /// Whether the offer has expired given the duration since the Unix epoch.
 652         pub fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 653                 self.contents.is_expired_no_std(duration_since_epoch)
 654         }
 655
 656         /// Returns whether the given quantity is valid for the offer.
 657         pub fn is_valid_quantity(&self, quantity: u64) -> bool {
 658                 self.contents.is_valid_quantity(quantity)
 659         }
 660
 661         /// Returns whether a quantity is expected in an [`InvoiceRequest`] for the offer.
 662         ///
 663         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 664         pub fn expects_quantity(&self) -> bool {
 665                 self.contents.expects_quantity()
 666         }
 667 }
 668
 669 macro_rules! request_invoice_derived_payer_id { ($self: ident, $builder: ty) => {
 670         /// Similar to [`Offer::request_invoice`] except it:
 671         /// - derives the [`InvoiceRequest::payer_id`] such that a different key can be used for each
 672         ///   request,
 673         /// - sets [`InvoiceRequest::payer_metadata`] when [`InvoiceRequestBuilder::build`] is called
 674         ///   such that it can be used by [`Bolt12Invoice::verify`] to determine if the invoice was
 675         ///   requested using a base [`ExpandedKey`] from which the payer id was derived, and
 676         /// - includes the [`PaymentId`] encrypted in [`InvoiceRequest::payer_metadata`] so that it can
 677         ///   be used when sending the payment for the requested invoice.
 678         ///
 679         /// Useful to protect the sender's privacy.
 680         ///
 681         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 682         /// [`InvoiceRequest::payer_metadata`]: crate::offers::invoice_request::InvoiceRequest::payer_metadata
 683         /// [`Bolt12Invoice::verify`]: crate::offers::invoice::Bolt12Invoice::verify
 684         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 685         pub fn request_invoice_deriving_payer_id<
 686                 'a, 'b, ES: Deref,
 687                 #[cfg(not(c_bindings))]
 688                 T: secp256k1::Signing
 689         >(
 690                 &'a $self, expanded_key: &ExpandedKey, entropy_source: ES,
 691                 #[cfg(not(c_bindings))]
 692                 secp_ctx: &'b Secp256k1<T>,
 693                 #[cfg(c_bindings)]
 694                 secp_ctx: &'b Secp256k1<secp256k1::All>,
 695                 payment_id: PaymentId
 696         ) -> Result<$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_payer_id($self, expanded_key, entropy_source, secp_ctx, payment_id))
 705         }
 706 } }
 707
 708 macro_rules! request_invoice_explicit_payer_id { ($self: ident, $builder: ty) => {
 709         /// Similar to [`Offer::request_invoice_deriving_payer_id`] except uses `payer_id` for the
 710         /// [`InvoiceRequest::payer_id`] instead of deriving a different key for each request.
 711         ///
 712         /// Useful for recurring payments using the same `payer_id` with different invoices.
 713         ///
 714         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 715         pub fn request_invoice_deriving_metadata<ES: Deref>(
 716                 &$self, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 717                 payment_id: PaymentId
 718         ) -> Result<$builder, Bolt12SemanticError>
 719         where
 720                 ES::Target: EntropySource,
 721         {
 722                 if $self.offer_features().requires_unknown_bits() {
 723                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 724                 }
 725
 726                 Ok(<$builder>::deriving_metadata($self, payer_id, expanded_key, entropy_source, payment_id))
 727         }
 728
 729         /// Creates an [`InvoiceRequestBuilder`] for the offer with the given `metadata` and `payer_id`,
 730         /// which will be reflected in the `Bolt12Invoice` response.
 731         ///
 732         /// The `metadata` is useful for including information about the derivation of `payer_id` such
 733         /// that invoice response handling can be stateless. Also serves as payer-provided entropy while
 734         /// hashing in the signature calculation.
 735         ///
 736         /// This should not leak any information such as by using a simple BIP-32 derivation path.
 737         /// Otherwise, payments may be correlated.
 738         ///
 739         /// Errors if the offer contains unknown required features.
 740         ///
 741         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 742         pub fn request_invoice(
 743                 &$self, metadata: Vec<u8>, payer_id: PublicKey
 744         ) -> Result<$builder, Bolt12SemanticError> {
 745                 if $self.offer_features().requires_unknown_bits() {
 746                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 747                 }
 748
 749                 Ok(<$builder>::new($self, metadata, payer_id))
 750         }
 751 } }
 752
 753 #[cfg(not(c_bindings))]
 754 impl Offer {
 755         request_invoice_derived_payer_id!(self, InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T>);
 756         request_invoice_explicit_payer_id!(self, InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>);
 757 }
 758
 759 #[cfg(c_bindings)]
 760 impl Offer {
 761         request_invoice_derived_payer_id!(self, InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b>);
 762         request_invoice_explicit_payer_id!(self, InvoiceRequestWithExplicitPayerIdBuilder);
 763 }
 764
 765 #[cfg(test)]
 766 impl Offer {
 767         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 768                 self.contents.as_tlv_stream()
 769         }
 770 }
 771
 772 impl AsRef<[u8]> for Offer {
 773         fn as_ref(&self) -> &[u8] {
 774                 &self.bytes
 775         }
 776 }
 777
 778 impl PartialEq for Offer {
 779         fn eq(&self, other: &Self) -> bool {
 780                 self.bytes.eq(&other.bytes)
 781         }
 782 }
 783
 784 impl Eq for Offer {}
 785
 786 impl Hash for Offer {
 787         fn hash<H: Hasher>(&self, state: &mut H) {
 788                 self.bytes.hash(state);
 789         }
 790 }
 791
 792 impl OfferContents {
 793         pub fn chains(&self) -> Vec<ChainHash> {
 794                 self.chains.as_ref().cloned().unwrap_or_else(|| vec![self.implied_chain()])
 795         }
 796
 797         pub fn implied_chain(&self) -> ChainHash {
 798                 ChainHash::using_genesis_block(Network::Bitcoin)
 799         }
 800
 801         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 802                 self.chains().contains(&chain)
 803         }
 804
 805         pub fn metadata(&self) -> Option<&Vec<u8>> {
 806                 self.metadata.as_ref().and_then(|metadata| metadata.as_bytes())
 807         }
 808
 809         pub fn amount(&self) -> Option<Amount> {
 810                 self.amount
 811         }
 812
 813         pub fn description(&self) -> Option<PrintableString> {
 814                 self.description.as_ref().map(|description| PrintableString(description))
 815         }
 816
 817         pub fn features(&self) -> &OfferFeatures {
 818                 &self.features
 819         }
 820
 821         pub fn absolute_expiry(&self) -> Option<Duration> {
 822                 self.absolute_expiry
 823         }
 824
 825         #[cfg(feature = "std")]
 826         pub(super) fn is_expired(&self) -> bool {
 827                 SystemTime::UNIX_EPOCH
 828                         .elapsed()
 829                         .map(|duration_since_epoch| self.is_expired_no_std(duration_since_epoch))
 830                         .unwrap_or(false)
 831         }
 832
 833         pub(super) fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 834                 self.absolute_expiry
 835                         .map(|absolute_expiry| duration_since_epoch > absolute_expiry)
 836                         .unwrap_or(false)
 837         }
 838
 839         pub fn issuer(&self) -> Option<PrintableString> {
 840                 self.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 841         }
 842
 843         pub fn paths(&self) -> &[BlindedPath] {
 844                 self.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 845         }
 846
 847         pub(super) fn check_amount_msats_for_quantity(
 848                 &self, amount_msats: Option<u64>, quantity: Option<u64>
 849         ) -> Result<(), Bolt12SemanticError> {
 850                 let offer_amount_msats = match self.amount {
 851                         None => 0,
 852                         Some(Amount::Bitcoin { amount_msats }) => amount_msats,
 853                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 854                 };
 855
 856                 if !self.expects_quantity() || quantity.is_some() {
 857                         let expected_amount_msats = offer_amount_msats.checked_mul(quantity.unwrap_or(1))
 858                                 .ok_or(Bolt12SemanticError::InvalidAmount)?;
 859                         let amount_msats = amount_msats.unwrap_or(expected_amount_msats);
 860
 861                         if amount_msats < expected_amount_msats {
 862                                 return Err(Bolt12SemanticError::InsufficientAmount);
 863                         }
 864
 865                         if amount_msats > MAX_VALUE_MSAT {
 866                                 return Err(Bolt12SemanticError::InvalidAmount);
 867                         }
 868                 }
 869
 870                 Ok(())
 871         }
 872
 873         pub fn supported_quantity(&self) -> Quantity {
 874                 self.supported_quantity
 875         }
 876
 877         pub(super) fn check_quantity(&self, quantity: Option<u64>) -> Result<(), Bolt12SemanticError> {
 878                 let expects_quantity = self.expects_quantity();
 879                 match quantity {
 880                         None if expects_quantity => Err(Bolt12SemanticError::MissingQuantity),
 881                         Some(_) if !expects_quantity => Err(Bolt12SemanticError::UnexpectedQuantity),
 882                         Some(quantity) if !self.is_valid_quantity(quantity) => {
 883                                 Err(Bolt12SemanticError::InvalidQuantity)
 884                         },
 885                         _ => Ok(()),
 886                 }
 887         }
 888
 889         fn is_valid_quantity(&self, quantity: u64) -> bool {
 890                 match self.supported_quantity {
 891                         Quantity::Bounded(n) => quantity <= n.get(),
 892                         Quantity::Unbounded => quantity > 0,
 893                         Quantity::One => quantity == 1,
 894                 }
 895         }
 896
 897         fn expects_quantity(&self) -> bool {
 898                 match self.supported_quantity {
 899                         Quantity::Bounded(_) => true,
 900                         Quantity::Unbounded => true,
 901                         Quantity::One => false,
 902                 }
 903         }
 904
 905         pub(super) fn signing_pubkey(&self) -> Option<PublicKey> {
 906                 self.signing_pubkey
 907         }
 908
 909         /// Verifies that the offer metadata was produced from the offer in the TLV stream.
 910         pub(super) fn verify<T: secp256k1::Signing>(
 911                 &self, bytes: &[u8], key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 912         ) -> Result<(OfferId, Option<KeyPair>), ()> {
 913                 match self.metadata() {
 914                         Some(metadata) => {
 915                                 let tlv_stream = TlvStream::new(bytes).range(OFFER_TYPES).filter(|record| {
 916                                         match record.r#type {
 917                                                 OFFER_METADATA_TYPE => false,
 918                                                 OFFER_NODE_ID_TYPE => {
 919                                                         !self.metadata.as_ref().unwrap().derives_recipient_keys()
 920                                                 },
 921                                                 _ => true,
 922                                         }
 923                                 });
 924                                 let signing_pubkey = match self.signing_pubkey() {
 925                                         Some(signing_pubkey) => signing_pubkey,
 926                                         None => return Err(()),
 927                                 };
 928                                 let keys = signer::verify_recipient_metadata(
 929                                         metadata, key, IV_BYTES, signing_pubkey, tlv_stream, secp_ctx
 930                                 )?;
 931
 932                                 let offer_id = OfferId::from_valid_invreq_tlv_stream(bytes);
 933
 934                                 Ok((offer_id, keys))
 935                         },
 936                         None => Err(()),
 937                 }
 938         }
 939
 940         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 941                 let (currency, amount) = match &self.amount {
 942                         None => (None, None),
 943                         Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)),
 944                         Some(Amount::Currency { iso4217_code, amount }) => (
 945                                 Some(iso4217_code), Some(*amount)
 946                         ),
 947                 };
 948
 949                 let features = {
 950                         if self.features == OfferFeatures::empty() { None } else { Some(&self.features) }
 951                 };
 952
 953                 OfferTlvStreamRef {
 954                         chains: self.chains.as_ref(),
 955                         metadata: self.metadata(),
 956                         currency,
 957                         amount,
 958                         description: self.description.as_ref(),
 959                         features,
 960                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 961                         paths: self.paths.as_ref(),
 962                         issuer: self.issuer.as_ref(),
 963                         quantity_max: self.supported_quantity.to_tlv_record(),
 964                         node_id: self.signing_pubkey.as_ref(),
 965                 }
 966         }
 967 }
 968
 969 impl Writeable for Offer {
 970         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 971                 WithoutLength(&self.bytes).write(writer)
 972         }
 973 }
 974
 975 impl Writeable for OfferContents {
 976         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 977                 self.as_tlv_stream().write(writer)
 978         }
 979 }
 980
 981 /// The minimum amount required for an item in an [`Offer`], denominated in either bitcoin or
 982 /// another currency.
 983 #[derive(Clone, Copy, Debug, PartialEq)]
 984 pub enum Amount {
 985         /// An amount of bitcoin.
 986         Bitcoin {
 987                 /// The amount in millisatoshi.
 988                 amount_msats: u64,
 989         },
 990         /// An amount of currency specified using ISO 4712.
 991         Currency {
 992                 /// The currency that the amount is denominated in.
 993                 iso4217_code: CurrencyCode,
 994                 /// The amount in the currency unit adjusted by the ISO 4712 exponent (e.g., USD cents).
 995                 amount: u64,
 996         },
 997 }
 998
 999 /// An ISO 4712 three-letter currency code (e.g., USD).
1000 pub type CurrencyCode = [u8; 3];
1001
1002 /// Quantity of items supported by an [`Offer`].
1003 #[derive(Clone, Copy, Debug, PartialEq)]
1004 pub enum Quantity {
1005         /// Up to a specific number of items (inclusive). Use when more than one item can be requested
1006         /// but is limited (e.g., because of per customer or inventory limits).
1007         ///
1008         /// May be used with `NonZeroU64::new(1)` but prefer to use [`Quantity::One`] if only one item
1009         /// is supported.
1010         Bounded(NonZeroU64),
1011         /// One or more items. Use when more than one item can be requested without any limit.
1012         Unbounded,
1013         /// Only one item. Use when only a single item can be requested.
1014         One,
1015 }
1016
1017 impl Quantity {
1018         fn to_tlv_record(&self) -> Option<u64> {
1019                 match self {
1020                         Quantity::Bounded(n) => Some(n.get()),
1021                         Quantity::Unbounded => Some(0),
1022                         Quantity::One => None,
1023                 }
1024         }
1025 }
1026
1027 /// Valid type range for offer TLV records.
1028 pub(super) const OFFER_TYPES: core::ops::Range<u64> = 1..80;
1029
1030 /// TLV record type for [`Offer::metadata`].
1031 const OFFER_METADATA_TYPE: u64 = 4;
1032
1033 /// TLV record type for [`Offer::signing_pubkey`].
1034 const OFFER_NODE_ID_TYPE: u64 = 22;
1035
1036 tlv_stream!(OfferTlvStream, OfferTlvStreamRef, OFFER_TYPES, {
1037         (2, chains: (Vec<ChainHash>, WithoutLength)),
1038         (OFFER_METADATA_TYPE, metadata: (Vec<u8>, WithoutLength)),
1039         (6, currency: CurrencyCode),
1040         (8, amount: (u64, HighZeroBytesDroppedBigSize)),
1041         (10, description: (String, WithoutLength)),
1042         (12, features: (OfferFeatures, WithoutLength)),
1043         (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)),
1044         (16, paths: (Vec<BlindedPath>, WithoutLength)),
1045         (18, issuer: (String, WithoutLength)),
1046         (20, quantity_max: (u64, HighZeroBytesDroppedBigSize)),
1047         (OFFER_NODE_ID_TYPE, node_id: PublicKey),
1048 });
1049
1050 impl Bech32Encode for Offer {
1051         const BECH32_HRP: &'static str = "lno";
1052 }
1053
1054 impl FromStr for Offer {
1055         type Err = Bolt12ParseError;
1056
1057         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
1058                 Self::from_bech32_str(s)
1059         }
1060 }
1061
1062 impl TryFrom<Vec<u8>> for Offer {
1063         type Error = Bolt12ParseError;
1064
1065         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
1066                 let offer = ParsedMessage::<OfferTlvStream>::try_from(bytes)?;
1067                 let ParsedMessage { bytes, tlv_stream } = offer;
1068                 let contents = OfferContents::try_from(tlv_stream)?;
1069                 let id = OfferId::from_valid_offer_tlv_stream(&bytes);
1070
1071                 Ok(Offer { bytes, contents, id })
1072         }
1073 }
1074
1075 impl TryFrom<OfferTlvStream> for OfferContents {
1076         type Error = Bolt12SemanticError;
1077
1078         fn try_from(tlv_stream: OfferTlvStream) -> Result<Self, Self::Error> {
1079                 let OfferTlvStream {
1080                         chains, metadata, currency, amount, description, features, absolute_expiry, paths,
1081                         issuer, quantity_max, node_id,
1082                 } = tlv_stream;
1083
1084                 let metadata = metadata.map(|metadata| Metadata::Bytes(metadata));
1085
1086                 let amount = match (currency, amount) {
1087                         (None, None) => None,
1088                         (None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
1089                                 return Err(Bolt12SemanticError::InvalidAmount);
1090                         },
1091                         (None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
1092                         (Some(_), None) => return Err(Bolt12SemanticError::MissingAmount),
1093                         (Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),
1094                 };
1095
1096                 if amount.is_some() && description.is_none() {
1097                         return Err(Bolt12SemanticError::MissingDescription);
1098                 }
1099
1100                 let features = features.unwrap_or_else(OfferFeatures::empty);
1101
1102                 let absolute_expiry = absolute_expiry
1103                         .map(|seconds_from_epoch| Duration::from_secs(seconds_from_epoch));
1104
1105                 let supported_quantity = match quantity_max {
1106                         None => Quantity::One,
1107                         Some(0) => Quantity::Unbounded,
1108                         Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
1109                 };
1110
1111                 let (signing_pubkey, paths) = match (node_id, paths) {
1112                         (None, None) => return Err(Bolt12SemanticError::MissingSigningPubkey),
1113                         (_, Some(paths)) if paths.is_empty() => return Err(Bolt12SemanticError::MissingPaths),
1114                         (node_id, paths) => (node_id, paths),
1115                 };
1116
1117                 Ok(OfferContents {
1118                         chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
1119                         supported_quantity, signing_pubkey,
1120                 })
1121         }
1122 }
1123
1124 impl core::fmt::Display for Offer {
1125         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
1126                 self.fmt_bech32_str(f)
1127         }
1128 }
1129
1130 #[cfg(test)]
1131 mod tests {
1132         use super::{Amount, Offer, OfferTlvStreamRef, Quantity};
1133         #[cfg(not(c_bindings))]
1134         use {
1135                 super::OfferBuilder,
1136         };
1137         #[cfg(c_bindings)]
1138         use {
1139                 super::OfferWithExplicitMetadataBuilder as OfferBuilder,
1140         };
1141
1142         use bitcoin::blockdata::constants::ChainHash;
1143         use bitcoin::network::constants::Network;
1144         use bitcoin::secp256k1::Secp256k1;
1145         use core::num::NonZeroU64;
1146         use core::time::Duration;
1147         use crate::blinded_path::{BlindedHop, BlindedPath, IntroductionNode};
1148         use crate::sign::KeyMaterial;
1149         use crate::ln::features::OfferFeatures;
1150         use crate::ln::inbound_payment::ExpandedKey;
1151         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
1152         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
1153         use crate::offers::test_utils::*;
1154         use crate::util::ser::{BigSize, Writeable};
1155         use crate::util::string::PrintableString;
1156
1157         #[test]
1158         fn builds_offer_with_defaults() {
1159                 let offer = OfferBuilder::new(pubkey(42)).build().unwrap();
1160
1161                 let mut buffer = Vec::new();
1162                 offer.write(&mut buffer).unwrap();
1163
1164                 assert_eq!(offer.bytes, buffer.as_slice());
1165                 assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
1166                 assert!(offer.supports_chain(ChainHash::using_genesis_block(Network::Bitcoin)));
1167                 assert_eq!(offer.metadata(), None);
1168                 assert_eq!(offer.amount(), None);
1169                 assert_eq!(offer.description(), None);
1170                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1171                 assert_eq!(offer.absolute_expiry(), None);
1172                 #[cfg(feature = "std")]
1173                 assert!(!offer.is_expired());
1174                 assert_eq!(offer.paths(), &[]);
1175                 assert_eq!(offer.issuer(), None);
1176                 assert_eq!(offer.supported_quantity(), Quantity::One);
1177                 assert_eq!(offer.signing_pubkey(), Some(pubkey(42)));
1178
1179                 assert_eq!(
1180                         offer.as_tlv_stream(),
1181                         OfferTlvStreamRef {
1182                                 chains: None,
1183                                 metadata: None,
1184                                 currency: None,
1185                                 amount: None,
1186                                 description: None,
1187                                 features: None,
1188                                 absolute_expiry: None,
1189                                 paths: None,
1190                                 issuer: None,
1191                                 quantity_max: None,
1192                                 node_id: Some(&pubkey(42)),
1193                         },
1194                 );
1195
1196                 if let Err(e) = Offer::try_from(buffer) {
1197                         panic!("error parsing offer: {:?}", e);
1198                 }
1199         }
1200
1201         #[test]
1202         fn builds_offer_with_chains() {
1203                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
1204                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
1205
1206                 let offer = OfferBuilder::new(pubkey(42))
1207                         .chain(Network::Bitcoin)
1208                         .build()
1209                         .unwrap();
1210                 assert!(offer.supports_chain(mainnet));
1211                 assert_eq!(offer.chains(), vec![mainnet]);
1212                 assert_eq!(offer.as_tlv_stream().chains, None);
1213
1214                 let offer = OfferBuilder::new(pubkey(42))
1215                         .chain(Network::Testnet)
1216                         .build()
1217                         .unwrap();
1218                 assert!(offer.supports_chain(testnet));
1219                 assert_eq!(offer.chains(), vec![testnet]);
1220                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1221
1222                 let offer = OfferBuilder::new(pubkey(42))
1223                         .chain(Network::Testnet)
1224                         .chain(Network::Testnet)
1225                         .build()
1226                         .unwrap();
1227                 assert!(offer.supports_chain(testnet));
1228                 assert_eq!(offer.chains(), vec![testnet]);
1229                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1230
1231                 let offer = OfferBuilder::new(pubkey(42))
1232                         .chain(Network::Bitcoin)
1233                         .chain(Network::Testnet)
1234                         .build()
1235                         .unwrap();
1236                 assert!(offer.supports_chain(mainnet));
1237                 assert!(offer.supports_chain(testnet));
1238                 assert_eq!(offer.chains(), vec![mainnet, testnet]);
1239                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet]));
1240         }
1241
1242         #[test]
1243         fn builds_offer_with_metadata() {
1244                 let offer = OfferBuilder::new(pubkey(42))
1245                         .metadata(vec![42; 32]).unwrap()
1246                         .build()
1247                         .unwrap();
1248                 assert_eq!(offer.metadata(), Some(&vec![42; 32]));
1249                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![42; 32]));
1250
1251                 let offer = OfferBuilder::new(pubkey(42))
1252                         .metadata(vec![42; 32]).unwrap()
1253                         .metadata(vec![43; 32]).unwrap()
1254                         .build()
1255                         .unwrap();
1256                 assert_eq!(offer.metadata(), Some(&vec![43; 32]));
1257                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![43; 32]));
1258         }
1259
1260         #[test]
1261         fn builds_offer_with_metadata_derived() {
1262                 let node_id = recipient_pubkey();
1263                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1264                 let entropy = FixedEntropy {};
1265                 let secp_ctx = Secp256k1::new();
1266
1267                 #[cfg(c_bindings)]
1268                 use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
1269                 let offer = OfferBuilder
1270                         ::deriving_signing_pubkey(node_id, &expanded_key, &entropy, &secp_ctx)
1271                         .amount_msats(1000)
1272                         .build().unwrap();
1273                 assert_eq!(offer.signing_pubkey(), Some(node_id));
1274
1275                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1276                         .build().unwrap()
1277                         .sign(payer_sign).unwrap();
1278                 match invoice_request.verify(&expanded_key, &secp_ctx) {
1279                         Ok(invoice_request) => assert_eq!(invoice_request.offer_id, offer.id()),
1280                         Err(_) => panic!("unexpected error"),
1281                 }
1282
1283                 // Fails verification with altered offer field
1284                 let mut tlv_stream = offer.as_tlv_stream();
1285                 tlv_stream.amount = Some(100);
1286
1287                 let mut encoded_offer = Vec::new();
1288                 tlv_stream.write(&mut encoded_offer).unwrap();
1289
1290                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1291                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1292                         .build().unwrap()
1293                         .sign(payer_sign).unwrap();
1294                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1295
1296                 // Fails verification with altered metadata
1297                 let mut tlv_stream = offer.as_tlv_stream();
1298                 let metadata = tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1299                 tlv_stream.metadata = Some(&metadata);
1300
1301                 let mut encoded_offer = Vec::new();
1302                 tlv_stream.write(&mut encoded_offer).unwrap();
1303
1304                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1305                         .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_err());
1309         }
1310
1311         #[test]
1312         fn builds_offer_with_derived_signing_pubkey() {
1313                 let node_id = recipient_pubkey();
1314                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1315                 let entropy = FixedEntropy {};
1316                 let secp_ctx = Secp256k1::new();
1317
1318                 let blinded_path = BlindedPath {
1319                         introduction_node: IntroductionNode::NodeId(pubkey(40)),
1320                         blinding_point: pubkey(41),
1321                         blinded_hops: vec![
1322                                 BlindedHop { blinded_node_id: pubkey(42), encrypted_payload: vec![0; 43] },
1323                                 BlindedHop { blinded_node_id: node_id, encrypted_payload: vec![0; 44] },
1324                         ],
1325                 };
1326
1327                 #[cfg(c_bindings)]
1328                 use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
1329                 let offer = OfferBuilder
1330                         ::deriving_signing_pubkey(node_id, &expanded_key, &entropy, &secp_ctx)
1331                         .amount_msats(1000)
1332                         .path(blinded_path)
1333                         .build().unwrap();
1334                 assert_ne!(offer.signing_pubkey(), Some(node_id));
1335
1336                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1337                         .build().unwrap()
1338                         .sign(payer_sign).unwrap();
1339                 match invoice_request.verify(&expanded_key, &secp_ctx) {
1340                         Ok(invoice_request) => assert_eq!(invoice_request.offer_id, offer.id()),
1341                         Err(_) => panic!("unexpected error"),
1342                 }
1343
1344                 // Fails verification with altered offer field
1345                 let mut tlv_stream = offer.as_tlv_stream();
1346                 tlv_stream.amount = Some(100);
1347
1348                 let mut encoded_offer = Vec::new();
1349                 tlv_stream.write(&mut encoded_offer).unwrap();
1350
1351                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1352                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1353                         .build().unwrap()
1354                         .sign(payer_sign).unwrap();
1355                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1356
1357                 // Fails verification with altered signing pubkey
1358                 let mut tlv_stream = offer.as_tlv_stream();
1359                 let signing_pubkey = pubkey(1);
1360                 tlv_stream.node_id = Some(&signing_pubkey);
1361
1362                 let mut encoded_offer = Vec::new();
1363                 tlv_stream.write(&mut encoded_offer).unwrap();
1364
1365                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1366                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1367                         .build().unwrap()
1368                         .sign(payer_sign).unwrap();
1369                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1370         }
1371
1372         #[test]
1373         fn builds_offer_with_amount() {
1374                 let bitcoin_amount = Amount::Bitcoin { amount_msats: 1000 };
1375                 let currency_amount = Amount::Currency { iso4217_code: *b"USD", amount: 10 };
1376
1377                 let offer = OfferBuilder::new(pubkey(42))
1378                         .amount_msats(1000)
1379                         .build()
1380                         .unwrap();
1381                 let tlv_stream = offer.as_tlv_stream();
1382                 assert_eq!(offer.amount(), Some(bitcoin_amount));
1383                 assert_eq!(tlv_stream.amount, Some(1000));
1384                 assert_eq!(tlv_stream.currency, None);
1385
1386                 #[cfg(not(c_bindings))]
1387                 let builder = OfferBuilder::new(pubkey(42))
1388                         .amount(currency_amount.clone());
1389                 #[cfg(c_bindings)]
1390                 let mut builder = OfferBuilder::new(pubkey(42));
1391                 #[cfg(c_bindings)]
1392                 builder.amount(currency_amount.clone());
1393                 let tlv_stream = builder.offer.as_tlv_stream();
1394                 assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
1395                 assert_eq!(tlv_stream.amount, Some(10));
1396                 assert_eq!(tlv_stream.currency, Some(b"USD"));
1397                 match builder.build() {
1398                         Ok(_) => panic!("expected error"),
1399                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedCurrency),
1400                 }
1401
1402                 let offer = OfferBuilder::new(pubkey(42))
1403                         .amount(currency_amount.clone())
1404                         .amount(bitcoin_amount.clone())
1405                         .build()
1406                         .unwrap();
1407                 let tlv_stream = offer.as_tlv_stream();
1408                 assert_eq!(tlv_stream.amount, Some(1000));
1409                 assert_eq!(tlv_stream.currency, None);
1410
1411                 let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
1412                 match OfferBuilder::new(pubkey(42)).amount(invalid_amount).build() {
1413                         Ok(_) => panic!("expected error"),
1414                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1415                 }
1416         }
1417
1418         #[test]
1419         fn builds_offer_with_description() {
1420                 let offer = OfferBuilder::new(pubkey(42))
1421                         .description("foo".into())
1422                         .build()
1423                         .unwrap();
1424                 assert_eq!(offer.description(), Some(PrintableString("foo")));
1425                 assert_eq!(offer.as_tlv_stream().description, Some(&String::from("foo")));
1426
1427                 let offer = OfferBuilder::new(pubkey(42))
1428                         .description("foo".into())
1429                         .description("bar".into())
1430                         .build()
1431                         .unwrap();
1432                 assert_eq!(offer.description(), Some(PrintableString("bar")));
1433                 assert_eq!(offer.as_tlv_stream().description, Some(&String::from("bar")));
1434
1435                 let offer = OfferBuilder::new(pubkey(42))
1436                         .amount_msats(1000)
1437                         .build()
1438                         .unwrap();
1439                 assert_eq!(offer.description(), Some(PrintableString("")));
1440                 assert_eq!(offer.as_tlv_stream().description, Some(&String::from("")));
1441         }
1442
1443         #[test]
1444         fn builds_offer_with_features() {
1445                 let offer = OfferBuilder::new(pubkey(42))
1446                         .features_unchecked(OfferFeatures::unknown())
1447                         .build()
1448                         .unwrap();
1449                 assert_eq!(offer.offer_features(), &OfferFeatures::unknown());
1450                 assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
1451
1452                 let offer = OfferBuilder::new(pubkey(42))
1453                         .features_unchecked(OfferFeatures::unknown())
1454                         .features_unchecked(OfferFeatures::empty())
1455                         .build()
1456                         .unwrap();
1457                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1458                 assert_eq!(offer.as_tlv_stream().features, None);
1459         }
1460
1461         #[test]
1462         fn builds_offer_with_absolute_expiry() {
1463                 let future_expiry = Duration::from_secs(u64::max_value());
1464                 let past_expiry = Duration::from_secs(0);
1465                 let now = future_expiry - Duration::from_secs(1_000);
1466
1467                 let offer = OfferBuilder::new(pubkey(42))
1468                         .absolute_expiry(future_expiry)
1469                         .build()
1470                         .unwrap();
1471                 #[cfg(feature = "std")]
1472                 assert!(!offer.is_expired());
1473                 assert!(!offer.is_expired_no_std(now));
1474                 assert_eq!(offer.absolute_expiry(), Some(future_expiry));
1475                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
1476
1477                 let offer = OfferBuilder::new(pubkey(42))
1478                         .absolute_expiry(future_expiry)
1479                         .absolute_expiry(past_expiry)
1480                         .build()
1481                         .unwrap();
1482                 #[cfg(feature = "std")]
1483                 assert!(offer.is_expired());
1484                 assert!(offer.is_expired_no_std(now));
1485                 assert_eq!(offer.absolute_expiry(), Some(past_expiry));
1486                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
1487         }
1488
1489         #[test]
1490         fn builds_offer_with_paths() {
1491                 let paths = vec![
1492                         BlindedPath {
1493                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1494                                 blinding_point: pubkey(41),
1495                                 blinded_hops: vec![
1496                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1497                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1498                                 ],
1499                         },
1500                         BlindedPath {
1501                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1502                                 blinding_point: pubkey(41),
1503                                 blinded_hops: vec![
1504                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1505                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1506                                 ],
1507                         },
1508                 ];
1509
1510                 let offer = OfferBuilder::new(pubkey(42))
1511                         .path(paths[0].clone())
1512                         .path(paths[1].clone())
1513                         .build()
1514                         .unwrap();
1515                 let tlv_stream = offer.as_tlv_stream();
1516                 assert_eq!(offer.paths(), paths.as_slice());
1517                 assert_eq!(offer.signing_pubkey(), Some(pubkey(42)));
1518                 assert_ne!(pubkey(42), pubkey(44));
1519                 assert_eq!(tlv_stream.paths, Some(&paths));
1520                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
1521         }
1522
1523         #[test]
1524         fn builds_offer_with_issuer() {
1525                 let offer = OfferBuilder::new(pubkey(42))
1526                         .issuer("foo".into())
1527                         .build()
1528                         .unwrap();
1529                 assert_eq!(offer.issuer(), Some(PrintableString("foo")));
1530                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("foo")));
1531
1532                 let offer = OfferBuilder::new(pubkey(42))
1533                         .issuer("foo".into())
1534                         .issuer("bar".into())
1535                         .build()
1536                         .unwrap();
1537                 assert_eq!(offer.issuer(), Some(PrintableString("bar")));
1538                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("bar")));
1539         }
1540
1541         #[test]
1542         fn builds_offer_with_supported_quantity() {
1543                 let one = NonZeroU64::new(1).unwrap();
1544                 let ten = NonZeroU64::new(10).unwrap();
1545
1546                 let offer = OfferBuilder::new(pubkey(42))
1547                         .supported_quantity(Quantity::One)
1548                         .build()
1549                         .unwrap();
1550                 let tlv_stream = offer.as_tlv_stream();
1551                 assert_eq!(offer.supported_quantity(), Quantity::One);
1552                 assert_eq!(tlv_stream.quantity_max, None);
1553
1554                 let offer = OfferBuilder::new(pubkey(42))
1555                         .supported_quantity(Quantity::Unbounded)
1556                         .build()
1557                         .unwrap();
1558                 let tlv_stream = offer.as_tlv_stream();
1559                 assert_eq!(offer.supported_quantity(), Quantity::Unbounded);
1560                 assert_eq!(tlv_stream.quantity_max, Some(0));
1561
1562                 let offer = OfferBuilder::new(pubkey(42))
1563                         .supported_quantity(Quantity::Bounded(ten))
1564                         .build()
1565                         .unwrap();
1566                 let tlv_stream = offer.as_tlv_stream();
1567                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(ten));
1568                 assert_eq!(tlv_stream.quantity_max, Some(10));
1569
1570                 let offer = OfferBuilder::new(pubkey(42))
1571                         .supported_quantity(Quantity::Bounded(one))
1572                         .build()
1573                         .unwrap();
1574                 let tlv_stream = offer.as_tlv_stream();
1575                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(one));
1576                 assert_eq!(tlv_stream.quantity_max, Some(1));
1577
1578                 let offer = OfferBuilder::new(pubkey(42))
1579                         .supported_quantity(Quantity::Bounded(ten))
1580                         .supported_quantity(Quantity::One)
1581                         .build()
1582                         .unwrap();
1583                 let tlv_stream = offer.as_tlv_stream();
1584                 assert_eq!(offer.supported_quantity(), Quantity::One);
1585                 assert_eq!(tlv_stream.quantity_max, None);
1586         }
1587
1588         #[test]
1589         fn fails_requesting_invoice_with_unknown_required_features() {
1590                 match OfferBuilder::new(pubkey(42))
1591                         .features_unchecked(OfferFeatures::unknown())
1592                         .build().unwrap()
1593                         .request_invoice(vec![1; 32], pubkey(43))
1594                 {
1595                         Ok(_) => panic!("expected error"),
1596                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1597                 }
1598         }
1599
1600         #[test]
1601         fn parses_offer_with_chains() {
1602                 let offer = OfferBuilder::new(pubkey(42))
1603                         .chain(Network::Bitcoin)
1604                         .chain(Network::Testnet)
1605                         .build()
1606                         .unwrap();
1607                 if let Err(e) = offer.to_string().parse::<Offer>() {
1608                         panic!("error parsing offer: {:?}", e);
1609                 }
1610         }
1611
1612         #[test]
1613         fn parses_offer_with_amount() {
1614                 let offer = OfferBuilder::new(pubkey(42))
1615                         .amount(Amount::Bitcoin { amount_msats: 1000 })
1616                         .build()
1617                         .unwrap();
1618                 if let Err(e) = offer.to_string().parse::<Offer>() {
1619                         panic!("error parsing offer: {:?}", e);
1620                 }
1621
1622                 let mut tlv_stream = offer.as_tlv_stream();
1623                 tlv_stream.amount = Some(1000);
1624                 tlv_stream.currency = Some(b"USD");
1625
1626                 let mut encoded_offer = Vec::new();
1627                 tlv_stream.write(&mut encoded_offer).unwrap();
1628
1629                 if let Err(e) = Offer::try_from(encoded_offer) {
1630                         panic!("error parsing offer: {:?}", e);
1631                 }
1632
1633                 let mut tlv_stream = offer.as_tlv_stream();
1634                 tlv_stream.amount = None;
1635                 tlv_stream.currency = Some(b"USD");
1636
1637                 let mut encoded_offer = Vec::new();
1638                 tlv_stream.write(&mut encoded_offer).unwrap();
1639
1640                 match Offer::try_from(encoded_offer) {
1641                         Ok(_) => panic!("expected error"),
1642                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1643                 }
1644
1645                 let mut tlv_stream = offer.as_tlv_stream();
1646                 tlv_stream.amount = Some(MAX_VALUE_MSAT + 1);
1647                 tlv_stream.currency = None;
1648
1649                 let mut encoded_offer = Vec::new();
1650                 tlv_stream.write(&mut encoded_offer).unwrap();
1651
1652                 match Offer::try_from(encoded_offer) {
1653                         Ok(_) => panic!("expected error"),
1654                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1655                 }
1656         }
1657
1658         #[test]
1659         fn parses_offer_with_description() {
1660                 let offer = OfferBuilder::new(pubkey(42)).build().unwrap();
1661                 if let Err(e) = offer.to_string().parse::<Offer>() {
1662                         panic!("error parsing offer: {:?}", e);
1663                 }
1664
1665                 let offer = OfferBuilder::new(pubkey(42))
1666                         .description("foo".to_string())
1667                         .amount_msats(1000)
1668                         .build().unwrap();
1669                 if let Err(e) = offer.to_string().parse::<Offer>() {
1670                         panic!("error parsing offer: {:?}", e);
1671                 }
1672
1673                 let mut tlv_stream = offer.as_tlv_stream();
1674                 tlv_stream.description = None;
1675
1676                 let mut encoded_offer = Vec::new();
1677                 tlv_stream.write(&mut encoded_offer).unwrap();
1678
1679                 match Offer::try_from(encoded_offer) {
1680                         Ok(_) => panic!("expected error"),
1681                         Err(e) => {
1682                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription));
1683                         },
1684                 }
1685         }
1686
1687         #[test]
1688         fn parses_offer_with_paths() {
1689                 let offer = OfferBuilder::new(pubkey(42))
1690                         .path(BlindedPath {
1691                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1692                                 blinding_point: pubkey(41),
1693                                 blinded_hops: vec![
1694                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1695                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1696                                 ],
1697                         })
1698                         .path(BlindedPath {
1699                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1700                                 blinding_point: pubkey(41),
1701                                 blinded_hops: vec![
1702                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1703                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1704                                 ],
1705                         })
1706                         .build()
1707                         .unwrap();
1708                 if let Err(e) = offer.to_string().parse::<Offer>() {
1709                         panic!("error parsing offer: {:?}", e);
1710                 }
1711
1712                 let offer = OfferBuilder::new(pubkey(42))
1713                         .path(BlindedPath {
1714                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
1715                                 blinding_point: pubkey(41),
1716                                 blinded_hops: vec![
1717                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1718                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1719                                 ],
1720                         })
1721                         .clear_signing_pubkey()
1722                         .build()
1723                         .unwrap();
1724                 if let Err(e) = offer.to_string().parse::<Offer>() {
1725                         panic!("error parsing offer: {:?}", e);
1726                 }
1727
1728                 let mut builder = OfferBuilder::new(pubkey(42));
1729                 builder.offer.paths = Some(vec![]);
1730
1731                 let offer = builder.build().unwrap();
1732                 match offer.to_string().parse::<Offer>() {
1733                         Ok(_) => panic!("expected error"),
1734                         Err(e) => {
1735                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPaths));
1736                         },
1737                 }
1738         }
1739
1740         #[test]
1741         fn parses_offer_with_quantity() {
1742                 let offer = OfferBuilder::new(pubkey(42))
1743                         .supported_quantity(Quantity::One)
1744                         .build()
1745                         .unwrap();
1746                 if let Err(e) = offer.to_string().parse::<Offer>() {
1747                         panic!("error parsing offer: {:?}", e);
1748                 }
1749
1750                 let offer = OfferBuilder::new(pubkey(42))
1751                         .supported_quantity(Quantity::Unbounded)
1752                         .build()
1753                         .unwrap();
1754                 if let Err(e) = offer.to_string().parse::<Offer>() {
1755                         panic!("error parsing offer: {:?}", e);
1756                 }
1757
1758                 let offer = OfferBuilder::new(pubkey(42))
1759                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(10).unwrap()))
1760                         .build()
1761                         .unwrap();
1762                 if let Err(e) = offer.to_string().parse::<Offer>() {
1763                         panic!("error parsing offer: {:?}", e);
1764                 }
1765
1766                 let offer = OfferBuilder::new(pubkey(42))
1767                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(1).unwrap()))
1768                         .build()
1769                         .unwrap();
1770                 if let Err(e) = offer.to_string().parse::<Offer>() {
1771                         panic!("error parsing offer: {:?}", e);
1772                 }
1773         }
1774
1775         #[test]
1776         fn parses_offer_with_node_id() {
1777                 let offer = OfferBuilder::new(pubkey(42)).build().unwrap();
1778                 if let Err(e) = offer.to_string().parse::<Offer>() {
1779                         panic!("error parsing offer: {:?}", e);
1780                 }
1781
1782                 let mut tlv_stream = offer.as_tlv_stream();
1783                 tlv_stream.node_id = None;
1784
1785                 let mut encoded_offer = Vec::new();
1786                 tlv_stream.write(&mut encoded_offer).unwrap();
1787
1788                 match Offer::try_from(encoded_offer) {
1789                         Ok(_) => panic!("expected error"),
1790                         Err(e) => {
1791                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1792                         },
1793                 }
1794         }
1795
1796         #[test]
1797         fn fails_parsing_offer_with_extra_tlv_records() {
1798                 let offer = OfferBuilder::new(pubkey(42)).build().unwrap();
1799
1800                 let mut encoded_offer = Vec::new();
1801                 offer.write(&mut encoded_offer).unwrap();
1802                 BigSize(80).write(&mut encoded_offer).unwrap();
1803                 BigSize(32).write(&mut encoded_offer).unwrap();
1804                 [42u8; 32].write(&mut encoded_offer).unwrap();
1805
1806                 match Offer::try_from(encoded_offer) {
1807                         Ok(_) => panic!("expected error"),
1808                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1809                 }
1810         }
1811 }
1812
1813 #[cfg(test)]
1814 mod bolt12_tests {
1815         use super::{Bolt12ParseError, Bolt12SemanticError, Offer};
1816         use crate::ln::msgs::DecodeError;
1817
1818         #[test]
1819         fn parses_bech32_encoded_offers() {
1820                 let offers = [
1821                         // Minimal bolt12 offer
1822                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1823
1824                         // for testnet
1825                         "lno1qgsyxjtl6luzd9t3pr62xr7eemp6awnejusgf6gw45q75vcfqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1826
1827                         // for bitcoin (redundant)
1828                         "lno1qgsxlc5vp2m0rvmjcxn2y34wv0m5lyc7sdj7zksgn35dvxgqqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1829
1830                         // for bitcoin or liquidv1
1831                         "lno1qfqpge38tqmzyrdjj3x2qkdr5y80dlfw56ztq6yd9sme995g3gsxqqm0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq9qc4r9wd6zqan9vd6x7unnzcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1832
1833                         // with metadata
1834                         "lno1qsgqqqqqqqqqqqqqqqqqqqqqqqqqqzsv23jhxapqwejkxar0wfe3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1835
1836                         // with amount
1837                         "lno1pqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1838
1839                         // with currency
1840                         "lno1qcp4256ypqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1841
1842                         // with expiry
1843                         "lno1pgx9getnwss8vetrw3hhyucwq3ay997czcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1844
1845                         // with issuer
1846                         "lno1pgx9getnwss8vetrw3hhyucjy358garswvaz7tmzdak8gvfj9ehhyeeqgf85c4p3xgsxjmnyw4ehgunfv4e3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1847
1848                         // with quantity
1849                         "lno1pgx9getnwss8vetrw3hhyuc5qyz3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1850
1851                         // with unlimited (or unknown) quantity
1852                         "lno1pgx9getnwss8vetrw3hhyuc5qqtzzqhwcuj966ma9n9nqwqtl032xeyv6755yeflt235pmww58egx6rxry",
1853
1854                         // with single quantity (weird but valid)
1855                         "lno1pgx9getnwss8vetrw3hhyuc5qyq3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1856
1857                         // with feature
1858                         "lno1pgx9getnwss8vetrw3hhyucvp5yqqqqqqqqqqqqqqqqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1859
1860                         // with blinded path via Bob (0x424242...), blinding 020202...
1861                         "lno1pgx9getnwss8vetrw3hhyucs5ypjgef743p5fzqq9nqxh0ah7y87rzv3ud0eleps9kl2d5348hq2k8qzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgqpqqqqqqqqqqqqqqqqqqqqqqqqqqqzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqqzq3zyg3zyg3zyg3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1862
1863                         // ... and with second blinded path via Carol (0x434343...), blinding 020202...
1864                         "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",
1865
1866                         // unknown odd field
1867                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxfppf5x2mrvdamk7unvvs",
1868                 ];
1869                 for encoded_offer in &offers {
1870                         if let Err(e) = encoded_offer.parse::<Offer>() {
1871                                 panic!("Invalid offer ({:?}): {}", e, encoded_offer);
1872                         }
1873                 }
1874         }
1875
1876         #[test]
1877         fn fails_parsing_bech32_encoded_offers() {
1878                 // Malformed: fields out of order
1879                 assert_eq!(
1880                         "lno1zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszpgz5znzfgdzs".parse::<Offer>(),
1881                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1882                 );
1883
1884                 // Malformed: unknown even TLV type 78
1885                 assert_eq!(
1886                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpysgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1887                         Err(Bolt12ParseError::Decode(DecodeError::UnknownRequiredFeature)),
1888                 );
1889
1890                 // Malformed: empty
1891                 assert_eq!(
1892                         "lno1".parse::<Offer>(),
1893                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey)),
1894                 );
1895
1896                 // Malformed: truncated at type
1897                 assert_eq!(
1898                         "lno1pg".parse::<Offer>(),
1899                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1900                 );
1901
1902                 // Malformed: truncated in length
1903                 assert_eq!(
1904                         "lno1pt7s".parse::<Offer>(),
1905                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1906                 );
1907
1908                 // Malformed: truncated after length
1909                 assert_eq!(
1910                         "lno1pgpq".parse::<Offer>(),
1911                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1912                 );
1913
1914                 // Malformed: truncated in description
1915                 assert_eq!(
1916                         "lno1pgpyz".parse::<Offer>(),
1917                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1918                 );
1919
1920                 // Malformed: invalid offer_chains length
1921                 assert_eq!(
1922                         "lno1qgqszzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1923                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1924                 );
1925
1926                 // Malformed: truncated currency UTF-8
1927                 assert_eq!(
1928                         "lno1qcqcqzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1929                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1930                 );
1931
1932                 // Malformed: invalid currency UTF-8
1933                 assert_eq!(
1934                         "lno1qcpgqsg2q4q5cj2rg5tzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1935                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1936                 );
1937
1938                 // Malformed: truncated description UTF-8
1939                 assert_eq!(
1940                         "lno1pgqcq93pqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqy".parse::<Offer>(),
1941                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1942                 );
1943
1944                 // Malformed: invalid description UTF-8
1945                 assert_eq!(
1946                         "lno1pgpgqsgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1947                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1948                 );
1949
1950                 // Malformed: truncated offer_paths
1951                 assert_eq!(
1952                         "lno1pgz5znzfgdz3qqgpzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1953                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1954                 );
1955
1956                 // Malformed: zero num_hops in blinded_path
1957                 assert_eq!(
1958                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1959                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1960                 );
1961
1962                 // Malformed: truncated onionmsg_hop in blinded_path
1963                 assert_eq!(
1964                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1965                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1966                 );
1967
1968                 // Malformed: bad first_node_id in blinded_path
1969                 assert_eq!(
1970                         "lno1pgz5znzfgdz3qqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1971                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1972                 );
1973
1974                 // Malformed: bad blinding in blinded_path
1975                 assert_eq!(
1976                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcpqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1977                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1978                 );
1979
1980                 // Malformed: bad blinded_node_id in onionmsg_hop
1981                 assert_eq!(
1982                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1983                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1984                 );
1985
1986                 // Malformed: truncated issuer UTF-8
1987                 assert_eq!(
1988                         "lno1pgz5znzfgdz3yqvqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1989                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1990                 );
1991
1992                 // Malformed: invalid issuer UTF-8
1993                 assert_eq!(
1994                         "lno1pgz5znzfgdz3yq5qgytzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1995                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1996                 );
1997
1998                 // Malformed: invalid offer_node_id
1999                 assert_eq!(
2000                         "lno1pgz5znzfgdz3vggzqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvps".parse::<Offer>(),
2001                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
2002                 );
2003
2004                 // Contains type >= 80
2005                 assert_eq!(
2006                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgp9qgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
2007                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
2008                 );
2009
2010                 // TODO: Resolved in spec https://github.com/lightning/bolts/pull/798/files#r1334851959
2011                 // Contains unknown feature 22
2012                 assert!(
2013                         "lno1pgx9getnwss8vetrw3hhyucvqdqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg".parse::<Offer>().is_ok()
2014                 );
2015
2016                 // Missing offer_description
2017                 assert_eq!(
2018                         // TODO: Match the spec once it is updated.
2019                         "lno1pqpq86qkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg".parse::<Offer>(),
2020                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
2021                 );
2022
2023                 // Missing offer_node_id"
2024                 assert_eq!(
2025                         "lno1pgx9getnwss8vetrw3hhyuc".parse::<Offer>(),
2026                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey)),
2027                 );
2028         }
2029 }