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