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

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! Data structures and encoding for `offer` messages.
  11 //!
  12 //! An [`Offer`] represents an "offer to be paid." It is typically constructed by a merchant and
  13 //! published as a QR code to be scanned by a customer. The customer uses the offer to request an
  14 //! invoice from the merchant to be paid.
  15 //!
  16 //! # Example
  17 //!
  18 //! ```
  19 //! extern crate bitcoin;
  20 //! extern crate core;
  21 //! extern crate lightning;
  22 //!
  23 //! use core::convert::TryFrom;
  24 //! use core::num::NonZeroU64;
  25 //! use core::time::Duration;
  26 //!
  27 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
  28 //! use lightning::offers::offer::{Offer, OfferBuilder, Quantity};
  29 //! use lightning::offers::parse::Bolt12ParseError;
  30 //! use lightning::util::ser::{Readable, Writeable};
  31 //!
  32 //! # use lightning::blinded_path::BlindedPath;
  33 //! # #[cfg(feature = "std")]
  34 //! # use std::time::SystemTime;
  35 //! #
  36 //! # fn create_blinded_path() -> BlindedPath { unimplemented!() }
  37 //! # fn create_another_blinded_path() -> BlindedPath { unimplemented!() }
  38 //! #
  39 //! # #[cfg(feature = "std")]
  40 //! # fn build() -> Result<(), Bolt12ParseError> {
  41 //! let secp_ctx = Secp256k1::new();
  42 //! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
  43 //! let pubkey = PublicKey::from(keys);
  44 //!
  45 //! let expiration = SystemTime::now() + Duration::from_secs(24 * 60 * 60);
  46 //! let offer = OfferBuilder::new("coffee, large".to_string(), pubkey)
  47 //!     .amount_msats(20_000)
  48 //!     .supported_quantity(Quantity::Unbounded)
  49 //!     .absolute_expiry(expiration.duration_since(SystemTime::UNIX_EPOCH).unwrap())
  50 //!     .issuer("Foo Bar".to_string())
  51 //!     .path(create_blinded_path())
  52 //!     .path(create_another_blinded_path())
  53 //!     .build()?;
  54 //!
  55 //! // Encode as a bech32 string for use in a QR code.
  56 //! let encoded_offer = offer.to_string();
  57 //!
  58 //! // Parse from a bech32 string after scanning from a QR code.
  59 //! let offer = encoded_offer.parse::<Offer>()?;
  60 //!
  61 //! // Encode offer as raw bytes.
  62 //! let mut bytes = Vec::new();
  63 //! offer.write(&mut bytes).unwrap();
  64 //!
  65 //! // Decode raw bytes into an offer.
  66 //! let offer = Offer::try_from(bytes)?;
  67 //! # Ok(())
  68 //! # }
  69 //! ```
  70 //!
  71 //! # Note
  72 //!
  73 //! If constructing an [`Offer`] for use with a [`ChannelManager`], use
  74 //! [`ChannelManager::create_offer_builder`] instead of [`OfferBuilder::new`].
  75 //!
  76 //! [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
  77 //! [`ChannelManager::create_offer_builder`]: crate::ln::channelmanager::ChannelManager::create_offer_builder
  78
  79 use bitcoin::blockdata::constants::ChainHash;
  80 use bitcoin::network::constants::Network;
  81 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, self};
  82 use core::convert::TryFrom;
  83 use core::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::MAX_VALUE_MSAT;
  95 use crate::offers::merkle::TlvStream;
  96 use crate::offers::parse::{Bech32Encode, Bolt12ParseError, Bolt12SemanticError, ParsedMessage};
  97 use crate::offers::signer::{Metadata, MetadataMaterial, self};
  98 use crate::util::ser::{HighZeroBytesDroppedBigSize, WithoutLength, Writeable, Writer};
  99 use crate::util::string::PrintableString;
 100
 101 #[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 use crate::prelude::*;
 111
 112 #[cfg(feature = "std")]
 113 use std::time::SystemTime;
 114
 115 pub(super) const IV_BYTES: &[u8; IV_LEN] = b"LDK Offer ~~~~~~";
 116
 117 /// Builds an [`Offer`] for the "offer to be paid" flow.
 118 ///
 119 /// See [module-level documentation] for usage.
 120 ///
 121 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 122 ///
 123 /// [module-level documentation]: self
 124 pub struct OfferBuilder<'a, M: MetadataStrategy, T: secp256k1::Signing> {
 125         offer: OfferContents,
 126         metadata_strategy: core::marker::PhantomData<M>,
 127         secp_ctx: Option<&'a Secp256k1<T>>,
 128 }
 129
 130 /// Builds an [`Offer`] for the "offer to be paid" flow.
 131 ///
 132 /// See [module-level documentation] for usage.
 133 ///
 134 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 135 ///
 136 /// [module-level documentation]: self
 137 #[cfg(c_bindings)]
 138 pub struct OfferWithExplicitMetadataBuilder<'a> {
 139         offer: OfferContents,
 140         metadata_strategy: core::marker::PhantomData<ExplicitMetadata>,
 141         secp_ctx: Option<&'a Secp256k1<secp256k1::All>>,
 142 }
 143
 144 /// Builds an [`Offer`] for the "offer to be paid" flow.
 145 ///
 146 /// See [module-level documentation] for usage.
 147 ///
 148 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 149 ///
 150 /// [module-level documentation]: self
 151 #[cfg(c_bindings)]
 152 pub struct OfferWithDerivedMetadataBuilder<'a> {
 153         offer: OfferContents,
 154         metadata_strategy: core::marker::PhantomData<DerivedMetadata>,
 155         secp_ctx: Option<&'a Secp256k1<secp256k1::All>>,
 156 }
 157
 158 /// Indicates how [`Offer::metadata`] may be set.
 159 ///
 160 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 161 pub trait MetadataStrategy {}
 162
 163 /// [`Offer::metadata`] may be explicitly set or left empty.
 164 ///
 165 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 166 pub struct ExplicitMetadata {}
 167
 168 /// [`Offer::metadata`] will be derived.
 169 ///
 170 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 171 pub struct DerivedMetadata {}
 172
 173 impl MetadataStrategy for ExplicitMetadata {}
 174
 175 impl MetadataStrategy for DerivedMetadata {}
 176
 177 macro_rules! offer_explicit_metadata_builder_methods { (
 178         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr
 179 ) => {
 180         /// Creates a new builder for an offer setting the [`Offer::description`] and using the
 181         /// [`Offer::signing_pubkey`] for signing invoices. The associated secret key must be remembered
 182         /// while the offer is valid.
 183         ///
 184         /// Use a different pubkey per offer to avoid correlating offers.
 185         ///
 186         /// # Note
 187         ///
 188         /// If constructing an [`Offer`] for use with a [`ChannelManager`], use
 189         /// [`ChannelManager::create_offer_builder`] instead of [`OfferBuilder::new`].
 190         ///
 191         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 192         /// [`ChannelManager::create_offer_builder`]: crate::ln::channelmanager::ChannelManager::create_offer_builder
 193         pub fn new(description: String, signing_pubkey: PublicKey) -> Self {
 194                 Self {
 195                         offer: OfferContents {
 196                                 chains: None, metadata: None, amount: None, description,
 197                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 198                                 supported_quantity: Quantity::One, signing_pubkey,
 199                         },
 200                         metadata_strategy: core::marker::PhantomData,
 201                         secp_ctx: None,
 202                 }
 203         }
 204
 205         /// Sets the [`Offer::metadata`] to the given bytes.
 206         ///
 207         /// Successive calls to this method will override the previous setting.
 208         pub fn metadata(mut $self: $self_type, metadata: Vec<u8>) -> Result<$return_type, Bolt12SemanticError> {
 209                 $self.offer.metadata = Some(Metadata::Bytes(metadata));
 210                 Ok($return_value)
 211         }
 212 } }
 213
 214 macro_rules! offer_derived_metadata_builder_methods { ($secp_context: ty) => {
 215         /// Similar to [`OfferBuilder::new`] except, if [`OfferBuilder::path`] is called, the signing
 216         /// pubkey is derived from the given [`ExpandedKey`] and [`EntropySource`]. This provides
 217         /// recipient privacy by using a different signing pubkey for each offer. Otherwise, the
 218         /// provided `node_id` is used for the signing pubkey.
 219         ///
 220         /// Also, sets the metadata when [`OfferBuilder::build`] is called such that it can be used by
 221         /// [`InvoiceRequest::verify`] to determine if the request was produced for the offer given an
 222         /// [`ExpandedKey`].
 223         ///
 224         /// [`InvoiceRequest::verify`]: crate::offers::invoice_request::InvoiceRequest::verify
 225         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 226         pub fn deriving_signing_pubkey<ES: Deref>(
 227                 description: String, node_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 228                 secp_ctx: &'a Secp256k1<$secp_context>
 229         ) -> Self where ES::Target: EntropySource {
 230                 let nonce = Nonce::from_entropy_source(entropy_source);
 231                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, None);
 232                 let metadata = Metadata::DerivedSigningPubkey(derivation_material);
 233                 Self {
 234                         offer: OfferContents {
 235                                 chains: None, metadata: Some(metadata), amount: None, description,
 236                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 237                                 supported_quantity: Quantity::One, signing_pubkey: node_id,
 238                         },
 239                         metadata_strategy: core::marker::PhantomData,
 240                         secp_ctx: Some(secp_ctx),
 241                 }
 242         }
 243 } }
 244
 245 macro_rules! offer_builder_methods { (
 246         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
 247 ) => {
 248         /// Adds the chain hash of the given [`Network`] to [`Offer::chains`]. If not called,
 249         /// the chain hash of [`Network::Bitcoin`] is assumed to be the only one supported.
 250         ///
 251         /// See [`Offer::chains`] on how this relates to the payment currency.
 252         ///
 253         /// Successive calls to this method will add another chain hash.
 254         pub fn chain($self: $self_type, network: Network) -> $return_type {
 255                 $self.chain_hash(ChainHash::using_genesis_block(network))
 256         }
 257
 258         /// Adds the [`ChainHash`] to [`Offer::chains`]. If not called, the chain hash of
 259         /// [`Network::Bitcoin`] is assumed to be the only one supported.
 260         ///
 261         /// See [`Offer::chains`] on how this relates to the payment currency.
 262         ///
 263         /// Successive calls to this method will add another chain hash.
 264         pub(crate) fn chain_hash($($self_mut)* $self: $self_type, chain: ChainHash) -> $return_type {
 265                 let chains = $self.offer.chains.get_or_insert_with(Vec::new);
 266                 if !chains.contains(&chain) {
 267                         chains.push(chain);
 268                 }
 269
 270                 $return_value
 271         }
 272
 273         /// Sets the [`Offer::amount`] as an [`Amount::Bitcoin`].
 274         ///
 275         /// Successive calls to this method will override the previous setting.
 276         pub fn amount_msats($self: $self_type, amount_msats: u64) -> $return_type {
 277                 $self.amount(Amount::Bitcoin { amount_msats })
 278         }
 279
 280         /// Sets the [`Offer::amount`].
 281         ///
 282         /// Successive calls to this method will override the previous setting.
 283         pub(super) fn amount($($self_mut)* $self: $self_type, amount: Amount) -> $return_type {
 284                 $self.offer.amount = Some(amount);
 285                 $return_value
 286         }
 287
 288         /// Sets the [`Offer::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
 289         /// already passed is valid and can be checked for using [`Offer::is_expired`].
 290         ///
 291         /// Successive calls to this method will override the previous setting.
 292         pub fn absolute_expiry($($self_mut)* $self: $self_type, absolute_expiry: Duration) -> $return_type {
 293                 $self.offer.absolute_expiry = Some(absolute_expiry);
 294                 $return_value
 295         }
 296
 297         /// Sets the [`Offer::issuer`].
 298         ///
 299         /// Successive calls to this method will override the previous setting.
 300         pub fn issuer($($self_mut)* $self: $self_type, issuer: String) -> $return_type {
 301                 $self.offer.issuer = Some(issuer);
 302                 $return_value
 303         }
 304
 305         /// Adds a blinded path to [`Offer::paths`]. Must include at least one path if only connected by
 306         /// private channels or if [`Offer::signing_pubkey`] is not a public node id.
 307         ///
 308         /// Successive calls to this method will add another blinded path. Caller is responsible for not
 309         /// adding duplicate paths.
 310         pub fn path($($self_mut)* $self: $self_type, path: BlindedPath) -> $return_type {
 311                 $self.offer.paths.get_or_insert_with(Vec::new).push(path);
 312                 $return_value
 313         }
 314
 315         /// Sets the quantity of items for [`Offer::supported_quantity`]. If not called, defaults to
 316         /// [`Quantity::One`].
 317         ///
 318         /// Successive calls to this method will override the previous setting.
 319         pub fn supported_quantity($($self_mut)* $self: $self_type, quantity: Quantity) -> $return_type {
 320                 $self.offer.supported_quantity = quantity;
 321                 $return_value
 322         }
 323
 324         /// Builds an [`Offer`] from the builder's settings.
 325         pub fn build($($self_mut)* $self: $self_type) -> Result<Offer, Bolt12SemanticError> {
 326                 match $self.offer.amount {
 327                         Some(Amount::Bitcoin { amount_msats }) => {
 328                                 if amount_msats > MAX_VALUE_MSAT {
 329                                         return Err(Bolt12SemanticError::InvalidAmount);
 330                                 }
 331                         },
 332                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 333                         None => {},
 334                 }
 335
 336                 if let Some(chains) = &$self.offer.chains {
 337                         if chains.len() == 1 && chains[0] == $self.offer.implied_chain() {
 338                                 $self.offer.chains = None;
 339                         }
 340                 }
 341
 342                 Ok($self.build_without_checks())
 343         }
 344
 345         fn build_without_checks($($self_mut)* $self: $self_type) -> Offer {
 346                 // Create the metadata for stateless verification of an InvoiceRequest.
 347                 if let Some(mut metadata) = $self.offer.metadata.take() {
 348                         if metadata.has_derivation_material() {
 349                                 if $self.offer.paths.is_none() {
 350                                         metadata = metadata.without_keys();
 351                                 }
 352
 353                                 let mut tlv_stream = $self.offer.as_tlv_stream();
 354                                 debug_assert_eq!(tlv_stream.metadata, None);
 355                                 tlv_stream.metadata = None;
 356                                 if metadata.derives_recipient_keys() {
 357                                         tlv_stream.node_id = None;
 358                                 }
 359
 360                                 let (derived_metadata, keys) = metadata.derive_from(tlv_stream, $self.secp_ctx);
 361                                 metadata = derived_metadata;
 362                                 if let Some(keys) = keys {
 363                                         $self.offer.signing_pubkey = keys.public_key();
 364                                 }
 365                         }
 366
 367                         $self.offer.metadata = Some(metadata);
 368                 }
 369
 370                 let mut bytes = Vec::new();
 371                 $self.offer.write(&mut bytes).unwrap();
 372
 373                 Offer {
 374                         bytes,
 375                         #[cfg(not(c_bindings))]
 376                         contents: $self.offer,
 377                         #[cfg(c_bindings)]
 378                         contents: $self.offer.clone()
 379                 }
 380         }
 381 } }
 382
 383 #[cfg(test)]
 384 macro_rules! offer_builder_test_methods { (
 385         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
 386 ) => {
 387         #[cfg_attr(c_bindings, allow(dead_code))]
 388         fn features_unchecked($($self_mut)* $self: $self_type, features: OfferFeatures) -> $return_type {
 389                 $self.offer.features = features;
 390                 $return_value
 391         }
 392
 393         #[cfg_attr(c_bindings, allow(dead_code))]
 394         pub(crate) fn clear_paths($($self_mut)* $self: $self_type) -> $return_type {
 395                 $self.offer.paths = None;
 396                 $return_value
 397         }
 398
 399         #[cfg_attr(c_bindings, allow(dead_code))]
 400         pub(super) fn build_unchecked($self: $self_type) -> Offer {
 401                 $self.build_without_checks()
 402         }
 403 } }
 404
 405 impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
 406         offer_builder_methods!(self, Self, Self, self, mut);
 407
 408         #[cfg(test)]
 409         offer_builder_test_methods!(self, Self, Self, self, mut);
 410 }
 411
 412 impl<'a> OfferBuilder<'a, ExplicitMetadata, secp256k1::SignOnly> {
 413         offer_explicit_metadata_builder_methods!(self, Self, Self, self);
 414 }
 415
 416 impl<'a, T: secp256k1::Signing> OfferBuilder<'a, DerivedMetadata, T> {
 417         offer_derived_metadata_builder_methods!(T);
 418 }
 419
 420 #[cfg(all(c_bindings, not(test)))]
 421 impl<'a> OfferWithExplicitMetadataBuilder<'a> {
 422         offer_explicit_metadata_builder_methods!(self, &mut Self, (), ());
 423         offer_builder_methods!(self, &mut Self, (), ());
 424 }
 425
 426 #[cfg(all(c_bindings, test))]
 427 impl<'a> OfferWithExplicitMetadataBuilder<'a> {
 428         offer_explicit_metadata_builder_methods!(self, &mut Self, &mut Self, self);
 429         offer_builder_methods!(self, &mut Self, &mut Self, self);
 430         offer_builder_test_methods!(self, &mut Self, &mut Self, self);
 431 }
 432
 433 #[cfg(all(c_bindings, not(test)))]
 434 impl<'a> OfferWithDerivedMetadataBuilder<'a> {
 435         offer_derived_metadata_builder_methods!(secp256k1::All);
 436         offer_builder_methods!(self, &mut Self, (), ());
 437 }
 438
 439 #[cfg(all(c_bindings, test))]
 440 impl<'a> OfferWithDerivedMetadataBuilder<'a> {
 441         offer_derived_metadata_builder_methods!(secp256k1::All);
 442         offer_builder_methods!(self, &mut Self, &mut Self, self);
 443         offer_builder_test_methods!(self, &mut Self, &mut Self, self);
 444 }
 445
 446 #[cfg(c_bindings)]
 447 impl<'a> From<OfferBuilder<'a, DerivedMetadata, secp256k1::All>>
 448 for OfferWithDerivedMetadataBuilder<'a> {
 449         fn from(builder: OfferBuilder<'a, DerivedMetadata, secp256k1::All>) -> Self {
 450                 let OfferBuilder { offer, metadata_strategy, secp_ctx } = builder;
 451
 452                 Self { offer, metadata_strategy, secp_ctx }
 453         }
 454 }
 455
 456 /// An `Offer` is a potentially long-lived proposal for payment of a good or service.
 457 ///
 458 /// An offer is a precursor to an [`InvoiceRequest`]. A merchant publishes an offer from which a
 459 /// customer may request an [`Bolt12Invoice`] for a specific quantity and using an amount sufficient
 460 /// to cover that quantity (i.e., at least `quantity * amount`). See [`Offer::amount`].
 461 ///
 462 /// Offers may be denominated in currency other than bitcoin but are ultimately paid using the
 463 /// latter.
 464 ///
 465 /// Through the use of [`BlindedPath`]s, offers provide recipient privacy.
 466 ///
 467 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 468 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 469 #[derive(Clone, Debug)]
 470 pub struct Offer {
 471         // The serialized offer. Needed when creating an `InvoiceRequest` if the offer contains unknown
 472         // fields.
 473         pub(super) bytes: Vec<u8>,
 474         pub(super) contents: OfferContents,
 475 }
 476
 477 /// The contents of an [`Offer`], which may be shared with an [`InvoiceRequest`] or a
 478 /// [`Bolt12Invoice`].
 479 ///
 480 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 481 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 482 #[derive(Clone, Debug)]
 483 #[cfg_attr(test, derive(PartialEq))]
 484 pub(super) struct OfferContents {
 485         chains: Option<Vec<ChainHash>>,
 486         metadata: Option<Metadata>,
 487         amount: Option<Amount>,
 488         description: String,
 489         features: OfferFeatures,
 490         absolute_expiry: Option<Duration>,
 491         issuer: Option<String>,
 492         paths: Option<Vec<BlindedPath>>,
 493         supported_quantity: Quantity,
 494         signing_pubkey: PublicKey,
 495 }
 496
 497 macro_rules! offer_accessors { ($self: ident, $contents: expr) => {
 498         // TODO: Return a slice once ChainHash has constants.
 499         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1283
 500         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1286
 501         /// The chains that may be used when paying a requested invoice (e.g., bitcoin mainnet).
 502         /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats)
 503         /// for the selected chain.
 504         pub fn chains(&$self) -> Vec<bitcoin::blockdata::constants::ChainHash> {
 505                 $contents.chains()
 506         }
 507
 508         // TODO: Link to corresponding method in `InvoiceRequest`.
 509         /// Opaque bytes set by the originator. Useful for authentication and validating fields since it
 510         /// is reflected in `invoice_request` messages along with all the other fields from the `offer`.
 511         pub fn metadata(&$self) -> Option<&Vec<u8>> {
 512                 $contents.metadata()
 513         }
 514
 515         /// The minimum amount required for a successful payment of a single item.
 516         pub fn amount(&$self) -> Option<&$crate::offers::offer::Amount> {
 517                 $contents.amount()
 518         }
 519
 520         /// A complete description of the purpose of the payment. Intended to be displayed to the user
 521         /// but with the caveat that it has not been verified in any way.
 522         pub fn description(&$self) -> $crate::util::string::PrintableString {
 523                 $contents.description()
 524         }
 525
 526         /// Features pertaining to the offer.
 527         pub fn offer_features(&$self) -> &$crate::ln::features::OfferFeatures {
 528                 &$contents.features()
 529         }
 530
 531         /// Duration since the Unix epoch when an invoice should no longer be requested.
 532         ///
 533         /// If `None`, the offer does not expire.
 534         pub fn absolute_expiry(&$self) -> Option<core::time::Duration> {
 535                 $contents.absolute_expiry()
 536         }
 537
 538         /// The issuer of the offer, possibly beginning with `user@domain` or `domain`. Intended to be
 539         /// displayed to the user but with the caveat that it has not been verified in any way.
 540         pub fn issuer(&$self) -> Option<$crate::util::string::PrintableString> {
 541                 $contents.issuer()
 542         }
 543
 544         /// Paths to the recipient originating from publicly reachable nodes. Blinded paths provide
 545         /// recipient privacy by obfuscating its node id.
 546         pub fn paths(&$self) -> &[$crate::blinded_path::BlindedPath] {
 547                 $contents.paths()
 548         }
 549
 550         /// The quantity of items supported.
 551         pub fn supported_quantity(&$self) -> $crate::offers::offer::Quantity {
 552                 $contents.supported_quantity()
 553         }
 554
 555         /// The public key used by the recipient to sign invoices.
 556         pub fn signing_pubkey(&$self) -> bitcoin::secp256k1::PublicKey {
 557                 $contents.signing_pubkey()
 558         }
 559 } }
 560
 561 impl Offer {
 562         offer_accessors!(self, self.contents);
 563
 564         pub(super) fn implied_chain(&self) -> ChainHash {
 565                 self.contents.implied_chain()
 566         }
 567
 568         /// Returns whether the given chain is supported by the offer.
 569         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 570                 self.contents.supports_chain(chain)
 571         }
 572
 573         /// Whether the offer has expired.
 574         #[cfg(feature = "std")]
 575         pub fn is_expired(&self) -> bool {
 576                 self.contents.is_expired()
 577         }
 578
 579         /// Whether the offer has expired given the duration since the Unix epoch.
 580         pub fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 581                 self.contents.is_expired_no_std(duration_since_epoch)
 582         }
 583
 584         /// Returns whether the given quantity is valid for the offer.
 585         pub fn is_valid_quantity(&self, quantity: u64) -> bool {
 586                 self.contents.is_valid_quantity(quantity)
 587         }
 588
 589         /// Returns whether a quantity is expected in an [`InvoiceRequest`] for the offer.
 590         ///
 591         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 592         pub fn expects_quantity(&self) -> bool {
 593                 self.contents.expects_quantity()
 594         }
 595 }
 596
 597 macro_rules! request_invoice_derived_payer_id { ($self: ident, $builder: ty) => {
 598         /// Similar to [`Offer::request_invoice`] except it:
 599         /// - derives the [`InvoiceRequest::payer_id`] such that a different key can be used for each
 600         ///   request,
 601         /// - sets [`InvoiceRequest::payer_metadata`] when [`InvoiceRequestBuilder::build`] is called
 602         ///   such that it can be used by [`Bolt12Invoice::verify`] to determine if the invoice was
 603         ///   requested using a base [`ExpandedKey`] from which the payer id was derived, and
 604         /// - includes the [`PaymentId`] encrypted in [`InvoiceRequest::payer_metadata`] so that it can
 605         ///   be used when sending the payment for the requested invoice.
 606         ///
 607         /// Useful to protect the sender's privacy.
 608         ///
 609         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 610         /// [`InvoiceRequest::payer_metadata`]: crate::offers::invoice_request::InvoiceRequest::payer_metadata
 611         /// [`Bolt12Invoice::verify`]: crate::offers::invoice::Bolt12Invoice::verify
 612         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 613         pub fn request_invoice_deriving_payer_id<
 614                 'a, 'b, ES: Deref,
 615                 #[cfg(not(c_bindings))]
 616                 T: secp256k1::Signing
 617         >(
 618                 &'a $self, expanded_key: &ExpandedKey, entropy_source: ES,
 619                 #[cfg(not(c_bindings))]
 620                 secp_ctx: &'b Secp256k1<T>,
 621                 #[cfg(c_bindings)]
 622                 secp_ctx: &'b Secp256k1<secp256k1::All>,
 623                 payment_id: PaymentId
 624         ) -> Result<$builder, Bolt12SemanticError>
 625         where
 626                 ES::Target: EntropySource,
 627         {
 628                 if $self.offer_features().requires_unknown_bits() {
 629                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 630                 }
 631
 632                 Ok(<$builder>::deriving_payer_id($self, expanded_key, entropy_source, secp_ctx, payment_id))
 633         }
 634 } }
 635
 636 macro_rules! request_invoice_explicit_payer_id { ($self: ident, $builder: ty) => {
 637         /// Similar to [`Offer::request_invoice_deriving_payer_id`] except uses `payer_id` for the
 638         /// [`InvoiceRequest::payer_id`] instead of deriving a different key for each request.
 639         ///
 640         /// Useful for recurring payments using the same `payer_id` with different invoices.
 641         ///
 642         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 643         pub fn request_invoice_deriving_metadata<ES: Deref>(
 644                 &$self, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 645                 payment_id: PaymentId
 646         ) -> Result<$builder, Bolt12SemanticError>
 647         where
 648                 ES::Target: EntropySource,
 649         {
 650                 if $self.offer_features().requires_unknown_bits() {
 651                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 652                 }
 653
 654                 Ok(<$builder>::deriving_metadata($self, payer_id, expanded_key, entropy_source, payment_id))
 655         }
 656
 657         /// Creates an [`InvoiceRequestBuilder`] for the offer with the given `metadata` and `payer_id`,
 658         /// which will be reflected in the `Bolt12Invoice` response.
 659         ///
 660         /// The `metadata` is useful for including information about the derivation of `payer_id` such
 661         /// that invoice response handling can be stateless. Also serves as payer-provided entropy while
 662         /// hashing in the signature calculation.
 663         ///
 664         /// This should not leak any information such as by using a simple BIP-32 derivation path.
 665         /// Otherwise, payments may be correlated.
 666         ///
 667         /// Errors if the offer contains unknown required features.
 668         ///
 669         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 670         pub fn request_invoice(
 671                 &$self, metadata: Vec<u8>, payer_id: PublicKey
 672         ) -> Result<$builder, Bolt12SemanticError> {
 673                 if $self.offer_features().requires_unknown_bits() {
 674                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 675                 }
 676
 677                 Ok(<$builder>::new($self, metadata, payer_id))
 678         }
 679 } }
 680
 681 #[cfg(not(c_bindings))]
 682 impl Offer {
 683         request_invoice_derived_payer_id!(self, InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T>);
 684         request_invoice_explicit_payer_id!(self, InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>);
 685 }
 686
 687 #[cfg(c_bindings)]
 688 impl Offer {
 689         request_invoice_derived_payer_id!(self, InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b>);
 690         request_invoice_explicit_payer_id!(self, InvoiceRequestWithExplicitPayerIdBuilder);
 691 }
 692
 693 #[cfg(test)]
 694 impl Offer {
 695         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 696                 self.contents.as_tlv_stream()
 697         }
 698 }
 699
 700 impl AsRef<[u8]> for Offer {
 701         fn as_ref(&self) -> &[u8] {
 702                 &self.bytes
 703         }
 704 }
 705
 706 impl PartialEq for Offer {
 707         fn eq(&self, other: &Self) -> bool {
 708                 self.bytes.eq(&other.bytes)
 709         }
 710 }
 711
 712 impl Eq for Offer {}
 713
 714 impl Hash for Offer {
 715         fn hash<H: Hasher>(&self, state: &mut H) {
 716                 self.bytes.hash(state);
 717         }
 718 }
 719
 720 impl OfferContents {
 721         pub fn chains(&self) -> Vec<ChainHash> {
 722                 self.chains.as_ref().cloned().unwrap_or_else(|| vec![self.implied_chain()])
 723         }
 724
 725         pub fn implied_chain(&self) -> ChainHash {
 726                 ChainHash::using_genesis_block(Network::Bitcoin)
 727         }
 728
 729         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 730                 self.chains().contains(&chain)
 731         }
 732
 733         pub fn metadata(&self) -> Option<&Vec<u8>> {
 734                 self.metadata.as_ref().and_then(|metadata| metadata.as_bytes())
 735         }
 736
 737         pub fn amount(&self) -> Option<&Amount> {
 738                 self.amount.as_ref()
 739         }
 740
 741         pub fn description(&self) -> PrintableString {
 742                 PrintableString(&self.description)
 743         }
 744
 745         pub fn features(&self) -> &OfferFeatures {
 746                 &self.features
 747         }
 748
 749         pub fn absolute_expiry(&self) -> Option<Duration> {
 750                 self.absolute_expiry
 751         }
 752
 753         #[cfg(feature = "std")]
 754         pub(super) fn is_expired(&self) -> bool {
 755                 SystemTime::UNIX_EPOCH
 756                         .elapsed()
 757                         .map(|duration_since_epoch| self.is_expired_no_std(duration_since_epoch))
 758                         .unwrap_or(false)
 759         }
 760
 761         pub(super) fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 762                 self.absolute_expiry
 763                         .map(|absolute_expiry| duration_since_epoch > absolute_expiry)
 764                         .unwrap_or(false)
 765         }
 766
 767         pub fn issuer(&self) -> Option<PrintableString> {
 768                 self.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 769         }
 770
 771         pub fn paths(&self) -> &[BlindedPath] {
 772                 self.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 773         }
 774
 775         pub(super) fn check_amount_msats_for_quantity(
 776                 &self, amount_msats: Option<u64>, quantity: Option<u64>
 777         ) -> Result<(), Bolt12SemanticError> {
 778                 let offer_amount_msats = match self.amount {
 779                         None => 0,
 780                         Some(Amount::Bitcoin { amount_msats }) => amount_msats,
 781                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 782                 };
 783
 784                 if !self.expects_quantity() || quantity.is_some() {
 785                         let expected_amount_msats = offer_amount_msats.checked_mul(quantity.unwrap_or(1))
 786                                 .ok_or(Bolt12SemanticError::InvalidAmount)?;
 787                         let amount_msats = amount_msats.unwrap_or(expected_amount_msats);
 788
 789                         if amount_msats < expected_amount_msats {
 790                                 return Err(Bolt12SemanticError::InsufficientAmount);
 791                         }
 792
 793                         if amount_msats > MAX_VALUE_MSAT {
 794                                 return Err(Bolt12SemanticError::InvalidAmount);
 795                         }
 796                 }
 797
 798                 Ok(())
 799         }
 800
 801         pub fn supported_quantity(&self) -> Quantity {
 802                 self.supported_quantity
 803         }
 804
 805         pub(super) fn check_quantity(&self, quantity: Option<u64>) -> Result<(), Bolt12SemanticError> {
 806                 let expects_quantity = self.expects_quantity();
 807                 match quantity {
 808                         None if expects_quantity => Err(Bolt12SemanticError::MissingQuantity),
 809                         Some(_) if !expects_quantity => Err(Bolt12SemanticError::UnexpectedQuantity),
 810                         Some(quantity) if !self.is_valid_quantity(quantity) => {
 811                                 Err(Bolt12SemanticError::InvalidQuantity)
 812                         },
 813                         _ => Ok(()),
 814                 }
 815         }
 816
 817         fn is_valid_quantity(&self, quantity: u64) -> bool {
 818                 match self.supported_quantity {
 819                         Quantity::Bounded(n) => quantity <= n.get(),
 820                         Quantity::Unbounded => quantity > 0,
 821                         Quantity::One => quantity == 1,
 822                 }
 823         }
 824
 825         fn expects_quantity(&self) -> bool {
 826                 match self.supported_quantity {
 827                         Quantity::Bounded(_) => true,
 828                         Quantity::Unbounded => true,
 829                         Quantity::One => false,
 830                 }
 831         }
 832
 833         pub(super) fn signing_pubkey(&self) -> PublicKey {
 834                 self.signing_pubkey
 835         }
 836
 837         /// Verifies that the offer metadata was produced from the offer in the TLV stream.
 838         pub(super) fn verify<T: secp256k1::Signing>(
 839                 &self, bytes: &[u8], key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 840         ) -> Result<Option<KeyPair>, ()> {
 841                 match self.metadata() {
 842                         Some(metadata) => {
 843                                 let tlv_stream = TlvStream::new(bytes).range(OFFER_TYPES).filter(|record| {
 844                                         match record.r#type {
 845                                                 OFFER_METADATA_TYPE => false,
 846                                                 OFFER_NODE_ID_TYPE => {
 847                                                         !self.metadata.as_ref().unwrap().derives_recipient_keys()
 848                                                 },
 849                                                 _ => true,
 850                                         }
 851                                 });
 852                                 signer::verify_recipient_metadata(
 853                                         metadata, key, IV_BYTES, self.signing_pubkey(), tlv_stream, secp_ctx
 854                                 )
 855                         },
 856                         None => Err(()),
 857                 }
 858         }
 859
 860         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 861                 let (currency, amount) = match &self.amount {
 862                         None => (None, None),
 863                         Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)),
 864                         Some(Amount::Currency { iso4217_code, amount }) => (
 865                                 Some(iso4217_code), Some(*amount)
 866                         ),
 867                 };
 868
 869                 let features = {
 870                         if self.features == OfferFeatures::empty() { None } else { Some(&self.features) }
 871                 };
 872
 873                 OfferTlvStreamRef {
 874                         chains: self.chains.as_ref(),
 875                         metadata: self.metadata(),
 876                         currency,
 877                         amount,
 878                         description: Some(&self.description),
 879                         features,
 880                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 881                         paths: self.paths.as_ref(),
 882                         issuer: self.issuer.as_ref(),
 883                         quantity_max: self.supported_quantity.to_tlv_record(),
 884                         node_id: Some(&self.signing_pubkey),
 885                 }
 886         }
 887 }
 888
 889 impl Writeable for Offer {
 890         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 891                 WithoutLength(&self.bytes).write(writer)
 892         }
 893 }
 894
 895 impl Writeable for OfferContents {
 896         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 897                 self.as_tlv_stream().write(writer)
 898         }
 899 }
 900
 901 /// The minimum amount required for an item in an [`Offer`], denominated in either bitcoin or
 902 /// another currency.
 903 #[derive(Clone, Debug, PartialEq)]
 904 pub enum Amount {
 905         /// An amount of bitcoin.
 906         Bitcoin {
 907                 /// The amount in millisatoshi.
 908                 amount_msats: u64,
 909         },
 910         /// An amount of currency specified using ISO 4712.
 911         Currency {
 912                 /// The currency that the amount is denominated in.
 913                 iso4217_code: CurrencyCode,
 914                 /// The amount in the currency unit adjusted by the ISO 4712 exponent (e.g., USD cents).
 915                 amount: u64,
 916         },
 917 }
 918
 919 /// An ISO 4712 three-letter currency code (e.g., USD).
 920 pub type CurrencyCode = [u8; 3];
 921
 922 /// Quantity of items supported by an [`Offer`].
 923 #[derive(Clone, Copy, Debug, PartialEq)]
 924 pub enum Quantity {
 925         /// Up to a specific number of items (inclusive). Use when more than one item can be requested
 926         /// but is limited (e.g., because of per customer or inventory limits).
 927         ///
 928         /// May be used with `NonZeroU64::new(1)` but prefer to use [`Quantity::One`] if only one item
 929         /// is supported.
 930         Bounded(NonZeroU64),
 931         /// One or more items. Use when more than one item can be requested without any limit.
 932         Unbounded,
 933         /// Only one item. Use when only a single item can be requested.
 934         One,
 935 }
 936
 937 impl Quantity {
 938         fn to_tlv_record(&self) -> Option<u64> {
 939                 match self {
 940                         Quantity::Bounded(n) => Some(n.get()),
 941                         Quantity::Unbounded => Some(0),
 942                         Quantity::One => None,
 943                 }
 944         }
 945 }
 946
 947 /// Valid type range for offer TLV records.
 948 pub(super) const OFFER_TYPES: core::ops::Range<u64> = 1..80;
 949
 950 /// TLV record type for [`Offer::metadata`].
 951 const OFFER_METADATA_TYPE: u64 = 4;
 952
 953 /// TLV record type for [`Offer::signing_pubkey`].
 954 const OFFER_NODE_ID_TYPE: u64 = 22;
 955
 956 tlv_stream!(OfferTlvStream, OfferTlvStreamRef, OFFER_TYPES, {
 957         (2, chains: (Vec<ChainHash>, WithoutLength)),
 958         (OFFER_METADATA_TYPE, metadata: (Vec<u8>, WithoutLength)),
 959         (6, currency: CurrencyCode),
 960         (8, amount: (u64, HighZeroBytesDroppedBigSize)),
 961         (10, description: (String, WithoutLength)),
 962         (12, features: (OfferFeatures, WithoutLength)),
 963         (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)),
 964         (16, paths: (Vec<BlindedPath>, WithoutLength)),
 965         (18, issuer: (String, WithoutLength)),
 966         (20, quantity_max: (u64, HighZeroBytesDroppedBigSize)),
 967         (OFFER_NODE_ID_TYPE, node_id: PublicKey),
 968 });
 969
 970 impl Bech32Encode for Offer {
 971         const BECH32_HRP: &'static str = "lno";
 972 }
 973
 974 impl FromStr for Offer {
 975         type Err = Bolt12ParseError;
 976
 977         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 978                 Self::from_bech32_str(s)
 979         }
 980 }
 981
 982 impl TryFrom<Vec<u8>> for Offer {
 983         type Error = Bolt12ParseError;
 984
 985         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 986                 let offer = ParsedMessage::<OfferTlvStream>::try_from(bytes)?;
 987                 let ParsedMessage { bytes, tlv_stream } = offer;
 988                 let contents = OfferContents::try_from(tlv_stream)?;
 989                 Ok(Offer { bytes, contents })
 990         }
 991 }
 992
 993 impl TryFrom<OfferTlvStream> for OfferContents {
 994         type Error = Bolt12SemanticError;
 995
 996         fn try_from(tlv_stream: OfferTlvStream) -> Result<Self, Self::Error> {
 997                 let OfferTlvStream {
 998                         chains, metadata, currency, amount, description, features, absolute_expiry, paths,
 999                         issuer, quantity_max, node_id,
1000                 } = tlv_stream;
1001
1002                 let metadata = metadata.map(|metadata| Metadata::Bytes(metadata));
1003
1004                 let amount = match (currency, amount) {
1005                         (None, None) => None,
1006                         (None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
1007                                 return Err(Bolt12SemanticError::InvalidAmount);
1008                         },
1009                         (None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
1010                         (Some(_), None) => return Err(Bolt12SemanticError::MissingAmount),
1011                         (Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),
1012                 };
1013
1014                 let description = match description {
1015                         None => return Err(Bolt12SemanticError::MissingDescription),
1016                         Some(description) => description,
1017                 };
1018
1019                 let features = features.unwrap_or_else(OfferFeatures::empty);
1020
1021                 let absolute_expiry = absolute_expiry
1022                         .map(|seconds_from_epoch| Duration::from_secs(seconds_from_epoch));
1023
1024                 let supported_quantity = match quantity_max {
1025                         None => Quantity::One,
1026                         Some(0) => Quantity::Unbounded,
1027                         Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
1028                 };
1029
1030                 let signing_pubkey = match node_id {
1031                         None => return Err(Bolt12SemanticError::MissingSigningPubkey),
1032                         Some(node_id) => node_id,
1033                 };
1034
1035                 Ok(OfferContents {
1036                         chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
1037                         supported_quantity, signing_pubkey,
1038                 })
1039         }
1040 }
1041
1042 impl core::fmt::Display for Offer {
1043         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
1044                 self.fmt_bech32_str(f)
1045         }
1046 }
1047
1048 #[cfg(test)]
1049 mod tests {
1050         use super::{Amount, Offer, OfferTlvStreamRef, Quantity};
1051         #[cfg(not(c_bindings))]
1052         use {
1053                 super::OfferBuilder,
1054         };
1055         #[cfg(c_bindings)]
1056         use {
1057                 super::OfferWithExplicitMetadataBuilder as OfferBuilder,
1058         };
1059
1060         use bitcoin::blockdata::constants::ChainHash;
1061         use bitcoin::network::constants::Network;
1062         use bitcoin::secp256k1::Secp256k1;
1063         use core::convert::TryFrom;
1064         use core::num::NonZeroU64;
1065         use core::time::Duration;
1066         use crate::blinded_path::{BlindedHop, BlindedPath};
1067         use crate::sign::KeyMaterial;
1068         use crate::ln::features::OfferFeatures;
1069         use crate::ln::inbound_payment::ExpandedKey;
1070         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
1071         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
1072         use crate::offers::test_utils::*;
1073         use crate::util::ser::{BigSize, Writeable};
1074         use crate::util::string::PrintableString;
1075
1076         #[test]
1077         fn builds_offer_with_defaults() {
1078                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1079
1080                 let mut buffer = Vec::new();
1081                 offer.write(&mut buffer).unwrap();
1082
1083                 assert_eq!(offer.bytes, buffer.as_slice());
1084                 assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
1085                 assert!(offer.supports_chain(ChainHash::using_genesis_block(Network::Bitcoin)));
1086                 assert_eq!(offer.metadata(), None);
1087                 assert_eq!(offer.amount(), None);
1088                 assert_eq!(offer.description(), PrintableString("foo"));
1089                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1090                 assert_eq!(offer.absolute_expiry(), None);
1091                 #[cfg(feature = "std")]
1092                 assert!(!offer.is_expired());
1093                 assert_eq!(offer.paths(), &[]);
1094                 assert_eq!(offer.issuer(), None);
1095                 assert_eq!(offer.supported_quantity(), Quantity::One);
1096                 assert_eq!(offer.signing_pubkey(), pubkey(42));
1097
1098                 assert_eq!(
1099                         offer.as_tlv_stream(),
1100                         OfferTlvStreamRef {
1101                                 chains: None,
1102                                 metadata: None,
1103                                 currency: None,
1104                                 amount: None,
1105                                 description: Some(&String::from("foo")),
1106                                 features: None,
1107                                 absolute_expiry: None,
1108                                 paths: None,
1109                                 issuer: None,
1110                                 quantity_max: None,
1111                                 node_id: Some(&pubkey(42)),
1112                         },
1113                 );
1114
1115                 if let Err(e) = Offer::try_from(buffer) {
1116                         panic!("error parsing offer: {:?}", e);
1117                 }
1118         }
1119
1120         #[test]
1121         fn builds_offer_with_chains() {
1122                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
1123                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
1124
1125                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1126                         .chain(Network::Bitcoin)
1127                         .build()
1128                         .unwrap();
1129                 assert!(offer.supports_chain(mainnet));
1130                 assert_eq!(offer.chains(), vec![mainnet]);
1131                 assert_eq!(offer.as_tlv_stream().chains, None);
1132
1133                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1134                         .chain(Network::Testnet)
1135                         .build()
1136                         .unwrap();
1137                 assert!(offer.supports_chain(testnet));
1138                 assert_eq!(offer.chains(), vec![testnet]);
1139                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1140
1141                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1142                         .chain(Network::Testnet)
1143                         .chain(Network::Testnet)
1144                         .build()
1145                         .unwrap();
1146                 assert!(offer.supports_chain(testnet));
1147                 assert_eq!(offer.chains(), vec![testnet]);
1148                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1149
1150                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1151                         .chain(Network::Bitcoin)
1152                         .chain(Network::Testnet)
1153                         .build()
1154                         .unwrap();
1155                 assert!(offer.supports_chain(mainnet));
1156                 assert!(offer.supports_chain(testnet));
1157                 assert_eq!(offer.chains(), vec![mainnet, testnet]);
1158                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet]));
1159         }
1160
1161         #[test]
1162         fn builds_offer_with_metadata() {
1163                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1164                         .metadata(vec![42; 32]).unwrap()
1165                         .build()
1166                         .unwrap();
1167                 assert_eq!(offer.metadata(), Some(&vec![42; 32]));
1168                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![42; 32]));
1169
1170                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1171                         .metadata(vec![42; 32]).unwrap()
1172                         .metadata(vec![43; 32]).unwrap()
1173                         .build()
1174                         .unwrap();
1175                 assert_eq!(offer.metadata(), Some(&vec![43; 32]));
1176                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![43; 32]));
1177         }
1178
1179         #[test]
1180         fn builds_offer_with_metadata_derived() {
1181                 let desc = "foo".to_string();
1182                 let node_id = recipient_pubkey();
1183                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1184                 let entropy = FixedEntropy {};
1185                 let secp_ctx = Secp256k1::new();
1186
1187                 #[cfg(c_bindings)]
1188                 use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
1189                 let offer = OfferBuilder
1190                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1191                         .amount_msats(1000)
1192                         .build().unwrap();
1193                 assert_eq!(offer.signing_pubkey(), node_id);
1194
1195                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1196                         .build().unwrap()
1197                         .sign(payer_sign).unwrap();
1198                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1199
1200                 // Fails verification with altered offer field
1201                 let mut tlv_stream = offer.as_tlv_stream();
1202                 tlv_stream.amount = Some(100);
1203
1204                 let mut encoded_offer = Vec::new();
1205                 tlv_stream.write(&mut encoded_offer).unwrap();
1206
1207                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1208                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1209                         .build().unwrap()
1210                         .sign(payer_sign).unwrap();
1211                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1212
1213                 // Fails verification with altered metadata
1214                 let mut tlv_stream = offer.as_tlv_stream();
1215                 let metadata = tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1216                 tlv_stream.metadata = Some(&metadata);
1217
1218                 let mut encoded_offer = Vec::new();
1219                 tlv_stream.write(&mut encoded_offer).unwrap();
1220
1221                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1222                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1223                         .build().unwrap()
1224                         .sign(payer_sign).unwrap();
1225                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1226         }
1227
1228         #[test]
1229         fn builds_offer_with_derived_signing_pubkey() {
1230                 let desc = "foo".to_string();
1231                 let node_id = recipient_pubkey();
1232                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1233                 let entropy = FixedEntropy {};
1234                 let secp_ctx = Secp256k1::new();
1235
1236                 let blinded_path = BlindedPath {
1237                         introduction_node_id: pubkey(40),
1238                         blinding_point: pubkey(41),
1239                         blinded_hops: vec![
1240                                 BlindedHop { blinded_node_id: pubkey(42), encrypted_payload: vec![0; 43] },
1241                                 BlindedHop { blinded_node_id: node_id, encrypted_payload: vec![0; 44] },
1242                         ],
1243                 };
1244
1245                 #[cfg(c_bindings)]
1246                 use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
1247                 let offer = OfferBuilder
1248                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1249                         .amount_msats(1000)
1250                         .path(blinded_path)
1251                         .build().unwrap();
1252                 assert_ne!(offer.signing_pubkey(), node_id);
1253
1254                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1255                         .build().unwrap()
1256                         .sign(payer_sign).unwrap();
1257                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1258
1259                 // Fails verification with altered offer field
1260                 let mut tlv_stream = offer.as_tlv_stream();
1261                 tlv_stream.amount = Some(100);
1262
1263                 let mut encoded_offer = Vec::new();
1264                 tlv_stream.write(&mut encoded_offer).unwrap();
1265
1266                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1267                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1268                         .build().unwrap()
1269                         .sign(payer_sign).unwrap();
1270                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1271
1272                 // Fails verification with altered signing pubkey
1273                 let mut tlv_stream = offer.as_tlv_stream();
1274                 let signing_pubkey = pubkey(1);
1275                 tlv_stream.node_id = Some(&signing_pubkey);
1276
1277                 let mut encoded_offer = Vec::new();
1278                 tlv_stream.write(&mut encoded_offer).unwrap();
1279
1280                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1281                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1282                         .build().unwrap()
1283                         .sign(payer_sign).unwrap();
1284                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1285         }
1286
1287         #[test]
1288         fn builds_offer_with_amount() {
1289                 let bitcoin_amount = Amount::Bitcoin { amount_msats: 1000 };
1290                 let currency_amount = Amount::Currency { iso4217_code: *b"USD", amount: 10 };
1291
1292                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1293                         .amount_msats(1000)
1294                         .build()
1295                         .unwrap();
1296                 let tlv_stream = offer.as_tlv_stream();
1297                 assert_eq!(offer.amount(), Some(&bitcoin_amount));
1298                 assert_eq!(tlv_stream.amount, Some(1000));
1299                 assert_eq!(tlv_stream.currency, None);
1300
1301                 #[cfg(not(c_bindings))]
1302                 let builder = OfferBuilder::new("foo".into(), pubkey(42))
1303                         .amount(currency_amount.clone());
1304                 #[cfg(c_bindings)]
1305                 let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
1306                 #[cfg(c_bindings)]
1307                 builder.amount(currency_amount.clone());
1308                 let tlv_stream = builder.offer.as_tlv_stream();
1309                 assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
1310                 assert_eq!(tlv_stream.amount, Some(10));
1311                 assert_eq!(tlv_stream.currency, Some(b"USD"));
1312                 match builder.build() {
1313                         Ok(_) => panic!("expected error"),
1314                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedCurrency),
1315                 }
1316
1317                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1318                         .amount(currency_amount.clone())
1319                         .amount(bitcoin_amount.clone())
1320                         .build()
1321                         .unwrap();
1322                 let tlv_stream = offer.as_tlv_stream();
1323                 assert_eq!(tlv_stream.amount, Some(1000));
1324                 assert_eq!(tlv_stream.currency, None);
1325
1326                 let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
1327                 match OfferBuilder::new("foo".into(), pubkey(42)).amount(invalid_amount).build() {
1328                         Ok(_) => panic!("expected error"),
1329                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1330                 }
1331         }
1332
1333         #[test]
1334         fn builds_offer_with_features() {
1335                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1336                         .features_unchecked(OfferFeatures::unknown())
1337                         .build()
1338                         .unwrap();
1339                 assert_eq!(offer.offer_features(), &OfferFeatures::unknown());
1340                 assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
1341
1342                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1343                         .features_unchecked(OfferFeatures::unknown())
1344                         .features_unchecked(OfferFeatures::empty())
1345                         .build()
1346                         .unwrap();
1347                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1348                 assert_eq!(offer.as_tlv_stream().features, None);
1349         }
1350
1351         #[test]
1352         fn builds_offer_with_absolute_expiry() {
1353                 let future_expiry = Duration::from_secs(u64::max_value());
1354                 let past_expiry = Duration::from_secs(0);
1355                 let now = future_expiry - Duration::from_secs(1_000);
1356
1357                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1358                         .absolute_expiry(future_expiry)
1359                         .build()
1360                         .unwrap();
1361                 #[cfg(feature = "std")]
1362                 assert!(!offer.is_expired());
1363                 assert!(!offer.is_expired_no_std(now));
1364                 assert_eq!(offer.absolute_expiry(), Some(future_expiry));
1365                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
1366
1367                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1368                         .absolute_expiry(future_expiry)
1369                         .absolute_expiry(past_expiry)
1370                         .build()
1371                         .unwrap();
1372                 #[cfg(feature = "std")]
1373                 assert!(offer.is_expired());
1374                 assert!(offer.is_expired_no_std(now));
1375                 assert_eq!(offer.absolute_expiry(), Some(past_expiry));
1376                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
1377         }
1378
1379         #[test]
1380         fn builds_offer_with_paths() {
1381                 let paths = vec![
1382                         BlindedPath {
1383                                 introduction_node_id: pubkey(40),
1384                                 blinding_point: pubkey(41),
1385                                 blinded_hops: vec![
1386                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1387                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1388                                 ],
1389                         },
1390                         BlindedPath {
1391                                 introduction_node_id: pubkey(40),
1392                                 blinding_point: pubkey(41),
1393                                 blinded_hops: vec![
1394                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1395                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1396                                 ],
1397                         },
1398                 ];
1399
1400                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1401                         .path(paths[0].clone())
1402                         .path(paths[1].clone())
1403                         .build()
1404                         .unwrap();
1405                 let tlv_stream = offer.as_tlv_stream();
1406                 assert_eq!(offer.paths(), paths.as_slice());
1407                 assert_eq!(offer.signing_pubkey(), pubkey(42));
1408                 assert_ne!(pubkey(42), pubkey(44));
1409                 assert_eq!(tlv_stream.paths, Some(&paths));
1410                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
1411         }
1412
1413         #[test]
1414         fn builds_offer_with_issuer() {
1415                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1416                         .issuer("bar".into())
1417                         .build()
1418                         .unwrap();
1419                 assert_eq!(offer.issuer(), Some(PrintableString("bar")));
1420                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("bar")));
1421
1422                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1423                         .issuer("bar".into())
1424                         .issuer("baz".into())
1425                         .build()
1426                         .unwrap();
1427                 assert_eq!(offer.issuer(), Some(PrintableString("baz")));
1428                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("baz")));
1429         }
1430
1431         #[test]
1432         fn builds_offer_with_supported_quantity() {
1433                 let one = NonZeroU64::new(1).unwrap();
1434                 let ten = NonZeroU64::new(10).unwrap();
1435
1436                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1437                         .supported_quantity(Quantity::One)
1438                         .build()
1439                         .unwrap();
1440                 let tlv_stream = offer.as_tlv_stream();
1441                 assert_eq!(offer.supported_quantity(), Quantity::One);
1442                 assert_eq!(tlv_stream.quantity_max, None);
1443
1444                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1445                         .supported_quantity(Quantity::Unbounded)
1446                         .build()
1447                         .unwrap();
1448                 let tlv_stream = offer.as_tlv_stream();
1449                 assert_eq!(offer.supported_quantity(), Quantity::Unbounded);
1450                 assert_eq!(tlv_stream.quantity_max, Some(0));
1451
1452                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1453                         .supported_quantity(Quantity::Bounded(ten))
1454                         .build()
1455                         .unwrap();
1456                 let tlv_stream = offer.as_tlv_stream();
1457                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(ten));
1458                 assert_eq!(tlv_stream.quantity_max, Some(10));
1459
1460                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1461                         .supported_quantity(Quantity::Bounded(one))
1462                         .build()
1463                         .unwrap();
1464                 let tlv_stream = offer.as_tlv_stream();
1465                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(one));
1466                 assert_eq!(tlv_stream.quantity_max, Some(1));
1467
1468                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1469                         .supported_quantity(Quantity::Bounded(ten))
1470                         .supported_quantity(Quantity::One)
1471                         .build()
1472                         .unwrap();
1473                 let tlv_stream = offer.as_tlv_stream();
1474                 assert_eq!(offer.supported_quantity(), Quantity::One);
1475                 assert_eq!(tlv_stream.quantity_max, None);
1476         }
1477
1478         #[test]
1479         fn fails_requesting_invoice_with_unknown_required_features() {
1480                 match OfferBuilder::new("foo".into(), pubkey(42))
1481                         .features_unchecked(OfferFeatures::unknown())
1482                         .build().unwrap()
1483                         .request_invoice(vec![1; 32], pubkey(43))
1484                 {
1485                         Ok(_) => panic!("expected error"),
1486                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1487                 }
1488         }
1489
1490         #[test]
1491         fn parses_offer_with_chains() {
1492                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1493                         .chain(Network::Bitcoin)
1494                         .chain(Network::Testnet)
1495                         .build()
1496                         .unwrap();
1497                 if let Err(e) = offer.to_string().parse::<Offer>() {
1498                         panic!("error parsing offer: {:?}", e);
1499                 }
1500         }
1501
1502         #[test]
1503         fn parses_offer_with_amount() {
1504                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1505                         .amount(Amount::Bitcoin { amount_msats: 1000 })
1506                         .build()
1507                         .unwrap();
1508                 if let Err(e) = offer.to_string().parse::<Offer>() {
1509                         panic!("error parsing offer: {:?}", e);
1510                 }
1511
1512                 let mut tlv_stream = offer.as_tlv_stream();
1513                 tlv_stream.amount = Some(1000);
1514                 tlv_stream.currency = Some(b"USD");
1515
1516                 let mut encoded_offer = Vec::new();
1517                 tlv_stream.write(&mut encoded_offer).unwrap();
1518
1519                 if let Err(e) = Offer::try_from(encoded_offer) {
1520                         panic!("error parsing offer: {:?}", e);
1521                 }
1522
1523                 let mut tlv_stream = offer.as_tlv_stream();
1524                 tlv_stream.amount = None;
1525                 tlv_stream.currency = Some(b"USD");
1526
1527                 let mut encoded_offer = Vec::new();
1528                 tlv_stream.write(&mut encoded_offer).unwrap();
1529
1530                 match Offer::try_from(encoded_offer) {
1531                         Ok(_) => panic!("expected error"),
1532                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1533                 }
1534
1535                 let mut tlv_stream = offer.as_tlv_stream();
1536                 tlv_stream.amount = Some(MAX_VALUE_MSAT + 1);
1537                 tlv_stream.currency = None;
1538
1539                 let mut encoded_offer = Vec::new();
1540                 tlv_stream.write(&mut encoded_offer).unwrap();
1541
1542                 match Offer::try_from(encoded_offer) {
1543                         Ok(_) => panic!("expected error"),
1544                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1545                 }
1546         }
1547
1548         #[test]
1549         fn parses_offer_with_description() {
1550                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1551                 if let Err(e) = offer.to_string().parse::<Offer>() {
1552                         panic!("error parsing offer: {:?}", e);
1553                 }
1554
1555                 let mut tlv_stream = offer.as_tlv_stream();
1556                 tlv_stream.description = None;
1557
1558                 let mut encoded_offer = Vec::new();
1559                 tlv_stream.write(&mut encoded_offer).unwrap();
1560
1561                 match Offer::try_from(encoded_offer) {
1562                         Ok(_) => panic!("expected error"),
1563                         Err(e) => {
1564                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription));
1565                         },
1566                 }
1567         }
1568
1569         #[test]
1570         fn parses_offer_with_paths() {
1571                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1572                         .path(BlindedPath {
1573                                 introduction_node_id: pubkey(40),
1574                                 blinding_point: pubkey(41),
1575                                 blinded_hops: vec![
1576                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1577                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1578                                 ],
1579                         })
1580                         .path(BlindedPath {
1581                                 introduction_node_id: pubkey(40),
1582                                 blinding_point: pubkey(41),
1583                                 blinded_hops: vec![
1584                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1585                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1586                                 ],
1587                         })
1588                         .build()
1589                         .unwrap();
1590                 if let Err(e) = offer.to_string().parse::<Offer>() {
1591                         panic!("error parsing offer: {:?}", e);
1592                 }
1593
1594                 let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
1595                 builder.offer.paths = Some(vec![]);
1596
1597                 let offer = builder.build().unwrap();
1598                 if let Err(e) = offer.to_string().parse::<Offer>() {
1599                         panic!("error parsing offer: {:?}", e);
1600                 }
1601         }
1602
1603         #[test]
1604         fn parses_offer_with_quantity() {
1605                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1606                         .supported_quantity(Quantity::One)
1607                         .build()
1608                         .unwrap();
1609                 if let Err(e) = offer.to_string().parse::<Offer>() {
1610                         panic!("error parsing offer: {:?}", e);
1611                 }
1612
1613                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1614                         .supported_quantity(Quantity::Unbounded)
1615                         .build()
1616                         .unwrap();
1617                 if let Err(e) = offer.to_string().parse::<Offer>() {
1618                         panic!("error parsing offer: {:?}", e);
1619                 }
1620
1621                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1622                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(10).unwrap()))
1623                         .build()
1624                         .unwrap();
1625                 if let Err(e) = offer.to_string().parse::<Offer>() {
1626                         panic!("error parsing offer: {:?}", e);
1627                 }
1628
1629                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1630                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(1).unwrap()))
1631                         .build()
1632                         .unwrap();
1633                 if let Err(e) = offer.to_string().parse::<Offer>() {
1634                         panic!("error parsing offer: {:?}", e);
1635                 }
1636         }
1637
1638         #[test]
1639         fn parses_offer_with_node_id() {
1640                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1641                 if let Err(e) = offer.to_string().parse::<Offer>() {
1642                         panic!("error parsing offer: {:?}", e);
1643                 }
1644
1645                 let mut tlv_stream = offer.as_tlv_stream();
1646                 tlv_stream.node_id = None;
1647
1648                 let mut encoded_offer = Vec::new();
1649                 tlv_stream.write(&mut encoded_offer).unwrap();
1650
1651                 match Offer::try_from(encoded_offer) {
1652                         Ok(_) => panic!("expected error"),
1653                         Err(e) => {
1654                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1655                         },
1656                 }
1657         }
1658
1659         #[test]
1660         fn fails_parsing_offer_with_extra_tlv_records() {
1661                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1662
1663                 let mut encoded_offer = Vec::new();
1664                 offer.write(&mut encoded_offer).unwrap();
1665                 BigSize(80).write(&mut encoded_offer).unwrap();
1666                 BigSize(32).write(&mut encoded_offer).unwrap();
1667                 [42u8; 32].write(&mut encoded_offer).unwrap();
1668
1669                 match Offer::try_from(encoded_offer) {
1670                         Ok(_) => panic!("expected error"),
1671                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1672                 }
1673         }
1674 }
1675
1676 #[cfg(test)]
1677 mod bolt12_tests {
1678         use super::{Bolt12ParseError, Bolt12SemanticError, Offer};
1679         use crate::ln::msgs::DecodeError;
1680
1681         #[test]
1682         fn parses_bech32_encoded_offers() {
1683                 let offers = [
1684                         // Minimal bolt12 offer
1685                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1686
1687                         // for testnet
1688                         "lno1qgsyxjtl6luzd9t3pr62xr7eemp6awnejusgf6gw45q75vcfqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1689
1690                         // for bitcoin (redundant)
1691                         "lno1qgsxlc5vp2m0rvmjcxn2y34wv0m5lyc7sdj7zksgn35dvxgqqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1692
1693                         // for bitcoin or liquidv1
1694                         "lno1qfqpge38tqmzyrdjj3x2qkdr5y80dlfw56ztq6yd9sme995g3gsxqqm0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq9qc4r9wd6zqan9vd6x7unnzcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1695
1696                         // with metadata
1697                         "lno1qsgqqqqqqqqqqqqqqqqqqqqqqqqqqzsv23jhxapqwejkxar0wfe3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1698
1699                         // with amount
1700                         "lno1pqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1701
1702                         // with currency
1703                         "lno1qcp4256ypqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1704
1705                         // with expiry
1706                         "lno1pgx9getnwss8vetrw3hhyucwq3ay997czcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1707
1708                         // with issuer
1709                         "lno1pgx9getnwss8vetrw3hhyucjy358garswvaz7tmzdak8gvfj9ehhyeeqgf85c4p3xgsxjmnyw4ehgunfv4e3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1710
1711                         // with quantity
1712                         "lno1pgx9getnwss8vetrw3hhyuc5qyz3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1713
1714                         // with unlimited (or unknown) quantity
1715                         "lno1pgx9getnwss8vetrw3hhyuc5qqtzzqhwcuj966ma9n9nqwqtl032xeyv6755yeflt235pmww58egx6rxry",
1716
1717                         // with single quantity (weird but valid)
1718                         "lno1pgx9getnwss8vetrw3hhyuc5qyq3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1719
1720                         // with feature
1721                         "lno1pgx9getnwss8vetrw3hhyucvp5yqqqqqqqqqqqqqqqqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1722
1723                         // with blinded path via Bob (0x424242...), blinding 020202...
1724                         "lno1pgx9getnwss8vetrw3hhyucs5ypjgef743p5fzqq9nqxh0ah7y87rzv3ud0eleps9kl2d5348hq2k8qzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgqpqqqqqqqqqqqqqqqqqqqqqqqqqqqzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqqzq3zyg3zyg3zyg3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1725
1726                         // ... and with second blinded path via Carol (0x434343...), blinding 020202...
1727                         "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",
1728
1729                         // unknown odd field
1730                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxfppf5x2mrvdamk7unvvs",
1731                 ];
1732                 for encoded_offer in &offers {
1733                         if let Err(e) = encoded_offer.parse::<Offer>() {
1734                                 panic!("Invalid offer ({:?}): {}", e, encoded_offer);
1735                         }
1736                 }
1737         }
1738
1739         #[test]
1740         fn fails_parsing_bech32_encoded_offers() {
1741                 // Malformed: fields out of order
1742                 assert_eq!(
1743                         "lno1zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszpgz5znzfgdzs".parse::<Offer>(),
1744                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1745                 );
1746
1747                 // Malformed: unknown even TLV type 78
1748                 assert_eq!(
1749                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpysgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1750                         Err(Bolt12ParseError::Decode(DecodeError::UnknownRequiredFeature)),
1751                 );
1752
1753                 // Malformed: empty
1754                 assert_eq!(
1755                         "lno1".parse::<Offer>(),
1756                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
1757                 );
1758
1759                 // Malformed: truncated at type
1760                 assert_eq!(
1761                         "lno1pg".parse::<Offer>(),
1762                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1763                 );
1764
1765                 // Malformed: truncated in length
1766                 assert_eq!(
1767                         "lno1pt7s".parse::<Offer>(),
1768                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1769                 );
1770
1771                 // Malformed: truncated after length
1772                 assert_eq!(
1773                         "lno1pgpq".parse::<Offer>(),
1774                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1775                 );
1776
1777                 // Malformed: truncated in description
1778                 assert_eq!(
1779                         "lno1pgpyz".parse::<Offer>(),
1780                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1781                 );
1782
1783                 // Malformed: invalid offer_chains length
1784                 assert_eq!(
1785                         "lno1qgqszzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1786                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1787                 );
1788
1789                 // Malformed: truncated currency UTF-8
1790                 assert_eq!(
1791                         "lno1qcqcqzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1792                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1793                 );
1794
1795                 // Malformed: invalid currency UTF-8
1796                 assert_eq!(
1797                         "lno1qcpgqsg2q4q5cj2rg5tzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1798                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1799                 );
1800
1801                 // Malformed: truncated description UTF-8
1802                 assert_eq!(
1803                         "lno1pgqcq93pqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqy".parse::<Offer>(),
1804                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1805                 );
1806
1807                 // Malformed: invalid description UTF-8
1808                 assert_eq!(
1809                         "lno1pgpgqsgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1810                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1811                 );
1812
1813                 // Malformed: truncated offer_paths
1814                 assert_eq!(
1815                         "lno1pgz5znzfgdz3qqgpzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1816                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1817                 );
1818
1819                 // Malformed: zero num_hops in blinded_path
1820                 assert_eq!(
1821                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1822                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1823                 );
1824
1825                 // Malformed: truncated onionmsg_hop in blinded_path
1826                 assert_eq!(
1827                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1828                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1829                 );
1830
1831                 // Malformed: bad first_node_id in blinded_path
1832                 assert_eq!(
1833                         "lno1pgz5znzfgdz3qqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1834                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1835                 );
1836
1837                 // Malformed: bad blinding in blinded_path
1838                 assert_eq!(
1839                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcpqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1840                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1841                 );
1842
1843                 // Malformed: bad blinded_node_id in onionmsg_hop
1844                 assert_eq!(
1845                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1846                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1847                 );
1848
1849                 // Malformed: truncated issuer UTF-8
1850                 assert_eq!(
1851                         "lno1pgz5znzfgdz3yqvqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1852                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1853                 );
1854
1855                 // Malformed: invalid issuer UTF-8
1856                 assert_eq!(
1857                         "lno1pgz5znzfgdz3yq5qgytzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1858                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1859                 );
1860
1861                 // Malformed: invalid offer_node_id
1862                 assert_eq!(
1863                         "lno1pgz5znzfgdz3vggzqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvps".parse::<Offer>(),
1864                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1865                 );
1866
1867                 // Contains type >= 80
1868                 assert_eq!(
1869                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgp9qgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1870                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1871                 );
1872
1873                 // TODO: Resolved in spec https://github.com/lightning/bolts/pull/798/files#r1334851959
1874                 // Contains unknown feature 22
1875                 assert!(
1876                         "lno1pgx9getnwss8vetrw3hhyucvqdqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg".parse::<Offer>().is_ok()
1877                 );
1878
1879                 // Missing offer_description
1880                 assert_eq!(
1881                         "lno1zcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese".parse::<Offer>(),
1882                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
1883                 );
1884
1885                 // Missing offer_node_id"
1886                 assert_eq!(
1887                         "lno1pgx9getnwss8vetrw3hhyuc".parse::<Offer>(),
1888                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey)),
1889                 );
1890         }
1891 }