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

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! Data structures and encoding for `offer` messages.
  11 //!
  12 //! An [`Offer`] represents an "offer to be paid." It is typically constructed by a merchant and
  13 //! published as a QR code to be scanned by a customer. The customer uses the offer to request an
  14 //! invoice from the merchant to be paid.
  15 //!
  16 //! # Example
  17 //!
  18 //! ```
  19 //! extern crate bitcoin;
  20 //! extern crate core;
  21 //! extern crate lightning;
  22 //!
  23 //! use core::convert::TryFrom;
  24 //! use core::num::NonZeroU64;
  25 //! use core::time::Duration;
  26 //!
  27 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
  28 //! use lightning::offers::offer::{Offer, OfferBuilder, Quantity};
  29 //! use lightning::offers::parse::Bolt12ParseError;
  30 //! use lightning::util::ser::{Readable, Writeable};
  31 //!
  32 //! # use lightning::blinded_path::BlindedPath;
  33 //! # #[cfg(feature = "std")]
  34 //! # use std::time::SystemTime;
  35 //! #
  36 //! # fn create_blinded_path() -> BlindedPath { unimplemented!() }
  37 //! # fn create_another_blinded_path() -> BlindedPath { unimplemented!() }
  38 //! #
  39 //! # #[cfg(feature = "std")]
  40 //! # fn build() -> Result<(), Bolt12ParseError> {
  41 //! let secp_ctx = Secp256k1::new();
  42 //! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
  43 //! let pubkey = PublicKey::from(keys);
  44 //!
  45 //! let expiration = SystemTime::now() + Duration::from_secs(24 * 60 * 60);
  46 //! let offer = OfferBuilder::new("coffee, large".to_string(), pubkey)
  47 //!     .amount_msats(20_000)
  48 //!     .supported_quantity(Quantity::Unbounded)
  49 //!     .absolute_expiry(expiration.duration_since(SystemTime::UNIX_EPOCH).unwrap())
  50 //!     .issuer("Foo Bar".to_string())
  51 //!     .path(create_blinded_path())
  52 //!     .path(create_another_blinded_path())
  53 //!     .build()?;
  54 //!
  55 //! // Encode as a bech32 string for use in a QR code.
  56 //! let encoded_offer = offer.to_string();
  57 //!
  58 //! // Parse from a bech32 string after scanning from a QR code.
  59 //! let offer = encoded_offer.parse::<Offer>()?;
  60 //!
  61 //! // Encode offer as raw bytes.
  62 //! let mut bytes = Vec::new();
  63 //! offer.write(&mut bytes).unwrap();
  64 //!
  65 //! // Decode raw bytes into an offer.
  66 //! let offer = Offer::try_from(bytes)?;
  67 //! # Ok(())
  68 //! # }
  69 //! ```
  70 //!
  71 //! # Note
  72 //!
  73 //! If constructing an [`Offer`] for use with a [`ChannelManager`], use
  74 //! [`ChannelManager::create_offer_builder`] instead of [`OfferBuilder::new`].
  75 //!
  76 //! [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
  77 //! [`ChannelManager::create_offer_builder`]: crate::ln::channelmanager::ChannelManager::create_offer_builder
  78
  79 use bitcoin::blockdata::constants::ChainHash;
  80 use bitcoin::network::constants::Network;
  81 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, self};
  82 use core::convert::TryFrom;
  83 use core::num::NonZeroU64;
  84 use core::ops::Deref;
  85 use core::str::FromStr;
  86 use core::time::Duration;
  87 use crate::sign::EntropySource;
  88 use crate::io;
  89 use crate::blinded_path::BlindedPath;
  90 use crate::ln::channelmanager::PaymentId;
  91 use crate::ln::features::OfferFeatures;
  92 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
  93 use crate::ln::msgs::MAX_VALUE_MSAT;
  94 use crate::offers::merkle::TlvStream;
  95 use crate::offers::parse::{Bech32Encode, Bolt12ParseError, Bolt12SemanticError, ParsedMessage};
  96 use crate::offers::signer::{Metadata, MetadataMaterial, self};
  97 use crate::util::ser::{HighZeroBytesDroppedBigSize, WithoutLength, Writeable, Writer};
  98 use crate::util::string::PrintableString;
  99
 100 #[cfg(not(c_bindings))]
 101 use {
 102         crate::offers::invoice_request::{DerivedPayerId, ExplicitPayerId, InvoiceRequestBuilder},
 103 };
 104 #[cfg(c_bindings)]
 105 use {
 106         crate::offers::invoice_request::{InvoiceRequestWithDerivedPayerIdBuilder, InvoiceRequestWithExplicitPayerIdBuilder},
 107 };
 108
 109 use crate::prelude::*;
 110
 111 #[cfg(feature = "std")]
 112 use std::time::SystemTime;
 113
 114 pub(super) const IV_BYTES: &[u8; IV_LEN] = b"LDK Offer ~~~~~~";
 115
 116 /// Builds an [`Offer`] for the "offer to be paid" flow.
 117 ///
 118 /// See [module-level documentation] for usage.
 119 ///
 120 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 121 ///
 122 /// [module-level documentation]: self
 123 pub struct OfferBuilder<'a, M: MetadataStrategy, T: secp256k1::Signing> {
 124         offer: OfferContents,
 125         metadata_strategy: core::marker::PhantomData<M>,
 126         secp_ctx: Option<&'a Secp256k1<T>>,
 127 }
 128
 129 /// Builds an [`Offer`] for the "offer to be paid" flow.
 130 ///
 131 /// See [module-level documentation] for usage.
 132 ///
 133 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 134 ///
 135 /// [module-level documentation]: self
 136 #[cfg(c_bindings)]
 137 pub struct OfferWithExplicitMetadataBuilder<'a> {
 138         offer: OfferContents,
 139         metadata_strategy: core::marker::PhantomData<ExplicitMetadata>,
 140         secp_ctx: Option<&'a Secp256k1<secp256k1::All>>,
 141 }
 142
 143 /// Builds an [`Offer`] for the "offer to be paid" flow.
 144 ///
 145 /// See [module-level documentation] for usage.
 146 ///
 147 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 148 ///
 149 /// [module-level documentation]: self
 150 #[cfg(c_bindings)]
 151 pub struct OfferWithDerivedMetadataBuilder<'a> {
 152         offer: OfferContents,
 153         metadata_strategy: core::marker::PhantomData<DerivedMetadata>,
 154         secp_ctx: Option<&'a Secp256k1<secp256k1::All>>,
 155 }
 156
 157 /// Indicates how [`Offer::metadata`] may be set.
 158 ///
 159 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 160 pub trait MetadataStrategy {}
 161
 162 /// [`Offer::metadata`] may be explicitly set or left empty.
 163 ///
 164 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 165 pub struct ExplicitMetadata {}
 166
 167 /// [`Offer::metadata`] will be derived.
 168 ///
 169 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 170 pub struct DerivedMetadata {}
 171
 172 impl MetadataStrategy for ExplicitMetadata {}
 173
 174 impl MetadataStrategy for DerivedMetadata {}
 175
 176 macro_rules! offer_explicit_metadata_builder_methods { (
 177         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr
 178 ) => {
 179         /// Creates a new builder for an offer setting the [`Offer::description`] and using the
 180         /// [`Offer::signing_pubkey`] for signing invoices. The associated secret key must be remembered
 181         /// while the offer is valid.
 182         ///
 183         /// Use a different pubkey per offer to avoid correlating offers.
 184         ///
 185         /// # Note
 186         ///
 187         /// If constructing an [`Offer`] for use with a [`ChannelManager`], use
 188         /// [`ChannelManager::create_offer_builder`] instead of [`OfferBuilder::new`].
 189         ///
 190         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 191         /// [`ChannelManager::create_offer_builder`]: crate::ln::channelmanager::ChannelManager::create_offer_builder
 192         pub fn new(description: String, signing_pubkey: PublicKey) -> Self {
 193                 Self {
 194                         offer: OfferContents {
 195                                 chains: None, metadata: None, amount: None, description,
 196                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 197                                 supported_quantity: Quantity::One, signing_pubkey,
 198                         },
 199                         metadata_strategy: core::marker::PhantomData,
 200                         secp_ctx: None,
 201                 }
 202         }
 203
 204         /// Sets the [`Offer::metadata`] to the given bytes.
 205         ///
 206         /// Successive calls to this method will override the previous setting.
 207         pub fn metadata(mut $self: $self_type, metadata: Vec<u8>) -> Result<$return_type, Bolt12SemanticError> {
 208                 $self.offer.metadata = Some(Metadata::Bytes(metadata));
 209                 Ok($return_value)
 210         }
 211 } }
 212
 213 macro_rules! offer_derived_metadata_builder_methods { ($secp_context: ty) => {
 214         /// Similar to [`OfferBuilder::new`] except, if [`OfferBuilder::path`] is called, the signing
 215         /// pubkey is derived from the given [`ExpandedKey`] and [`EntropySource`]. This provides
 216         /// recipient privacy by using a different signing pubkey for each offer. Otherwise, the
 217         /// provided `node_id` is used for the signing pubkey.
 218         ///
 219         /// Also, sets the metadata when [`OfferBuilder::build`] is called such that it can be used by
 220         /// [`InvoiceRequest::verify`] to determine if the request was produced for the offer given an
 221         /// [`ExpandedKey`].
 222         ///
 223         /// [`InvoiceRequest::verify`]: crate::offers::invoice_request::InvoiceRequest::verify
 224         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 225         pub fn deriving_signing_pubkey<ES: Deref>(
 226                 description: String, node_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 227                 secp_ctx: &'a Secp256k1<$secp_context>
 228         ) -> Self where ES::Target: EntropySource {
 229                 let nonce = Nonce::from_entropy_source(entropy_source);
 230                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, None);
 231                 let metadata = Metadata::DerivedSigningPubkey(derivation_material);
 232                 Self {
 233                         offer: OfferContents {
 234                                 chains: None, metadata: Some(metadata), amount: None, description,
 235                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
 236                                 supported_quantity: Quantity::One, signing_pubkey: node_id,
 237                         },
 238                         metadata_strategy: core::marker::PhantomData,
 239                         secp_ctx: Some(secp_ctx),
 240                 }
 241         }
 242 } }
 243
 244 macro_rules! offer_builder_methods { (
 245         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
 246 ) => {
 247         /// Adds the chain hash of the given [`Network`] to [`Offer::chains`]. If not called,
 248         /// the chain hash of [`Network::Bitcoin`] is assumed to be the only one supported.
 249         ///
 250         /// See [`Offer::chains`] on how this relates to the payment currency.
 251         ///
 252         /// Successive calls to this method will add another chain hash.
 253         pub fn chain($self: $self_type, network: Network) -> $return_type {
 254                 $self.chain_hash(ChainHash::using_genesis_block(network))
 255         }
 256
 257         /// Adds the [`ChainHash`] to [`Offer::chains`]. If not called, the chain hash of
 258         /// [`Network::Bitcoin`] is assumed to be the only one supported.
 259         ///
 260         /// See [`Offer::chains`] on how this relates to the payment currency.
 261         ///
 262         /// Successive calls to this method will add another chain hash.
 263         pub(crate) fn chain_hash($($self_mut)* $self: $self_type, chain: ChainHash) -> $return_type {
 264                 let chains = $self.offer.chains.get_or_insert_with(Vec::new);
 265                 if !chains.contains(&chain) {
 266                         chains.push(chain);
 267                 }
 268
 269                 $return_value
 270         }
 271
 272         /// Sets the [`Offer::amount`] as an [`Amount::Bitcoin`].
 273         ///
 274         /// Successive calls to this method will override the previous setting.
 275         pub fn amount_msats($self: $self_type, amount_msats: u64) -> $return_type {
 276                 $self.amount(Amount::Bitcoin { amount_msats })
 277         }
 278
 279         /// Sets the [`Offer::amount`].
 280         ///
 281         /// Successive calls to this method will override the previous setting.
 282         pub(super) fn amount($($self_mut)* $self: $self_type, amount: Amount) -> $return_type {
 283                 $self.offer.amount = Some(amount);
 284                 $return_value
 285         }
 286
 287         /// Sets the [`Offer::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
 288         /// already passed is valid and can be checked for using [`Offer::is_expired`].
 289         ///
 290         /// Successive calls to this method will override the previous setting.
 291         pub fn absolute_expiry($($self_mut)* $self: $self_type, absolute_expiry: Duration) -> $return_type {
 292                 $self.offer.absolute_expiry = Some(absolute_expiry);
 293                 $return_value
 294         }
 295
 296         /// Sets the [`Offer::issuer`].
 297         ///
 298         /// Successive calls to this method will override the previous setting.
 299         pub fn issuer($($self_mut)* $self: $self_type, issuer: String) -> $return_type {
 300                 $self.offer.issuer = Some(issuer);
 301                 $return_value
 302         }
 303
 304         /// Adds a blinded path to [`Offer::paths`]. Must include at least one path if only connected by
 305         /// private channels or if [`Offer::signing_pubkey`] is not a public node id.
 306         ///
 307         /// Successive calls to this method will add another blinded path. Caller is responsible for not
 308         /// adding duplicate paths.
 309         pub fn path($($self_mut)* $self: $self_type, path: BlindedPath) -> $return_type {
 310                 $self.offer.paths.get_or_insert_with(Vec::new).push(path);
 311                 $return_value
 312         }
 313
 314         /// Sets the quantity of items for [`Offer::supported_quantity`]. If not called, defaults to
 315         /// [`Quantity::One`].
 316         ///
 317         /// Successive calls to this method will override the previous setting.
 318         pub fn supported_quantity($($self_mut)* $self: $self_type, quantity: Quantity) -> $return_type {
 319                 $self.offer.supported_quantity = quantity;
 320                 $return_value
 321         }
 322
 323         /// Builds an [`Offer`] from the builder's settings.
 324         pub fn build($($self_mut)* $self: $self_type) -> Result<Offer, Bolt12SemanticError> {
 325                 match $self.offer.amount {
 326                         Some(Amount::Bitcoin { amount_msats }) => {
 327                                 if amount_msats > MAX_VALUE_MSAT {
 328                                         return Err(Bolt12SemanticError::InvalidAmount);
 329                                 }
 330                         },
 331                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 332                         None => {},
 333                 }
 334
 335                 if let Some(chains) = &$self.offer.chains {
 336                         if chains.len() == 1 && chains[0] == $self.offer.implied_chain() {
 337                                 $self.offer.chains = None;
 338                         }
 339                 }
 340
 341                 Ok($self.build_without_checks())
 342         }
 343
 344         fn build_without_checks($($self_mut)* $self: $self_type) -> Offer {
 345                 // Create the metadata for stateless verification of an InvoiceRequest.
 346                 if let Some(mut metadata) = $self.offer.metadata.take() {
 347                         if metadata.has_derivation_material() {
 348                                 if $self.offer.paths.is_none() {
 349                                         metadata = metadata.without_keys();
 350                                 }
 351
 352                                 let mut tlv_stream = $self.offer.as_tlv_stream();
 353                                 debug_assert_eq!(tlv_stream.metadata, None);
 354                                 tlv_stream.metadata = None;
 355                                 if metadata.derives_recipient_keys() {
 356                                         tlv_stream.node_id = None;
 357                                 }
 358
 359                                 let (derived_metadata, keys) = metadata.derive_from(tlv_stream, $self.secp_ctx);
 360                                 metadata = derived_metadata;
 361                                 if let Some(keys) = keys {
 362                                         $self.offer.signing_pubkey = keys.public_key();
 363                                 }
 364                         }
 365
 366                         $self.offer.metadata = Some(metadata);
 367                 }
 368
 369                 let mut bytes = Vec::new();
 370                 $self.offer.write(&mut bytes).unwrap();
 371
 372                 Offer {
 373                         bytes,
 374                         #[cfg(not(c_bindings))]
 375                         contents: $self.offer,
 376                         #[cfg(c_bindings)]
 377                         contents: $self.offer.clone()
 378                 }
 379         }
 380 } }
 381
 382 #[cfg(test)]
 383 macro_rules! offer_builder_test_methods { (
 384         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
 385 ) => {
 386         #[cfg_attr(c_bindings, allow(dead_code))]
 387         fn features_unchecked($($self_mut)* $self: $self_type, features: OfferFeatures) -> $return_type {
 388                 $self.offer.features = features;
 389                 $return_value
 390         }
 391
 392         #[cfg_attr(c_bindings, allow(dead_code))]
 393         pub(crate) fn clear_paths($($self_mut)* $self: $self_type) -> $return_type {
 394                 $self.offer.paths = None;
 395                 $return_value
 396         }
 397
 398         #[cfg_attr(c_bindings, allow(dead_code))]
 399         pub(super) fn build_unchecked($self: $self_type) -> Offer {
 400                 $self.build_without_checks()
 401         }
 402 } }
 403
 404 impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
 405         offer_builder_methods!(self, Self, Self, self, mut);
 406
 407         #[cfg(test)]
 408         offer_builder_test_methods!(self, Self, Self, self, mut);
 409 }
 410
 411 impl<'a> OfferBuilder<'a, ExplicitMetadata, secp256k1::SignOnly> {
 412         offer_explicit_metadata_builder_methods!(self, Self, Self, self);
 413 }
 414
 415 impl<'a, T: secp256k1::Signing> OfferBuilder<'a, DerivedMetadata, T> {
 416         offer_derived_metadata_builder_methods!(T);
 417 }
 418
 419 #[cfg(all(c_bindings, not(test)))]
 420 impl<'a> OfferWithExplicitMetadataBuilder<'a> {
 421         offer_explicit_metadata_builder_methods!(self, &mut Self, (), ());
 422         offer_builder_methods!(self, &mut Self, (), ());
 423 }
 424
 425 #[cfg(all(c_bindings, test))]
 426 impl<'a> OfferWithExplicitMetadataBuilder<'a> {
 427         offer_explicit_metadata_builder_methods!(self, &mut Self, &mut Self, self);
 428         offer_builder_methods!(self, &mut Self, &mut Self, self);
 429         offer_builder_test_methods!(self, &mut Self, &mut Self, self);
 430 }
 431
 432 #[cfg(all(c_bindings, not(test)))]
 433 impl<'a> OfferWithDerivedMetadataBuilder<'a> {
 434         offer_derived_metadata_builder_methods!(secp256k1::All);
 435         offer_builder_methods!(self, &mut Self, (), ());
 436 }
 437
 438 #[cfg(all(c_bindings, test))]
 439 impl<'a> OfferWithDerivedMetadataBuilder<'a> {
 440         offer_derived_metadata_builder_methods!(secp256k1::All);
 441         offer_builder_methods!(self, &mut Self, &mut Self, self);
 442         offer_builder_test_methods!(self, &mut Self, &mut Self, self);
 443 }
 444
 445 #[cfg(c_bindings)]
 446 impl<'a> From<OfferBuilder<'a, DerivedMetadata, secp256k1::All>>
 447 for OfferWithDerivedMetadataBuilder<'a> {
 448         fn from(builder: OfferBuilder<'a, DerivedMetadata, secp256k1::All>) -> Self {
 449                 let OfferBuilder { offer, metadata_strategy, secp_ctx } = builder;
 450
 451                 Self { offer, metadata_strategy, secp_ctx }
 452         }
 453 }
 454
 455 /// An `Offer` is a potentially long-lived proposal for payment of a good or service.
 456 ///
 457 /// An offer is a precursor to an [`InvoiceRequest`]. A merchant publishes an offer from which a
 458 /// customer may request an [`Bolt12Invoice`] for a specific quantity and using an amount sufficient
 459 /// to cover that quantity (i.e., at least `quantity * amount`). See [`Offer::amount`].
 460 ///
 461 /// Offers may be denominated in currency other than bitcoin but are ultimately paid using the
 462 /// latter.
 463 ///
 464 /// Through the use of [`BlindedPath`]s, offers provide recipient privacy.
 465 ///
 466 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 467 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 468 #[derive(Clone, Debug)]
 469 #[cfg_attr(test, derive(PartialEq))]
 470 pub struct Offer {
 471         // The serialized offer. Needed when creating an `InvoiceRequest` if the offer contains unknown
 472         // fields.
 473         pub(super) bytes: Vec<u8>,
 474         pub(super) contents: OfferContents,
 475 }
 476
 477 /// The contents of an [`Offer`], which may be shared with an [`InvoiceRequest`] or a
 478 /// [`Bolt12Invoice`].
 479 ///
 480 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 481 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 482 #[derive(Clone, Debug)]
 483 #[cfg_attr(test, derive(PartialEq))]
 484 pub(super) struct OfferContents {
 485         chains: Option<Vec<ChainHash>>,
 486         metadata: Option<Metadata>,
 487         amount: Option<Amount>,
 488         description: String,
 489         features: OfferFeatures,
 490         absolute_expiry: Option<Duration>,
 491         issuer: Option<String>,
 492         paths: Option<Vec<BlindedPath>>,
 493         supported_quantity: Quantity,
 494         signing_pubkey: PublicKey,
 495 }
 496
 497 macro_rules! offer_accessors { ($self: ident, $contents: expr) => {
 498         // TODO: Return a slice once ChainHash has constants.
 499         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1283
 500         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1286
 501         /// The chains that may be used when paying a requested invoice (e.g., bitcoin mainnet).
 502         /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats)
 503         /// for the selected chain.
 504         pub fn chains(&$self) -> Vec<bitcoin::blockdata::constants::ChainHash> {
 505                 $contents.chains()
 506         }
 507
 508         // TODO: Link to corresponding method in `InvoiceRequest`.
 509         /// Opaque bytes set by the originator. Useful for authentication and validating fields since it
 510         /// is reflected in `invoice_request` messages along with all the other fields from the `offer`.
 511         pub fn metadata(&$self) -> Option<&Vec<u8>> {
 512                 $contents.metadata()
 513         }
 514
 515         /// The minimum amount required for a successful payment of a single item.
 516         pub fn amount(&$self) -> Option<&$crate::offers::offer::Amount> {
 517                 $contents.amount()
 518         }
 519
 520         /// A complete description of the purpose of the payment. Intended to be displayed to the user
 521         /// but with the caveat that it has not been verified in any way.
 522         pub fn description(&$self) -> $crate::util::string::PrintableString {
 523                 $contents.description()
 524         }
 525
 526         /// Features pertaining to the offer.
 527         pub fn offer_features(&$self) -> &$crate::ln::features::OfferFeatures {
 528                 &$contents.features()
 529         }
 530
 531         /// Duration since the Unix epoch when an invoice should no longer be requested.
 532         ///
 533         /// If `None`, the offer does not expire.
 534         pub fn absolute_expiry(&$self) -> Option<core::time::Duration> {
 535                 $contents.absolute_expiry()
 536         }
 537
 538         /// The issuer of the offer, possibly beginning with `user@domain` or `domain`. Intended to be
 539         /// displayed to the user but with the caveat that it has not been verified in any way.
 540         pub fn issuer(&$self) -> Option<$crate::util::string::PrintableString> {
 541                 $contents.issuer()
 542         }
 543
 544         /// Paths to the recipient originating from publicly reachable nodes. Blinded paths provide
 545         /// recipient privacy by obfuscating its node id.
 546         pub fn paths(&$self) -> &[$crate::blinded_path::BlindedPath] {
 547                 $contents.paths()
 548         }
 549
 550         /// The quantity of items supported.
 551         pub fn supported_quantity(&$self) -> $crate::offers::offer::Quantity {
 552                 $contents.supported_quantity()
 553         }
 554
 555         /// The public key used by the recipient to sign invoices.
 556         pub fn signing_pubkey(&$self) -> bitcoin::secp256k1::PublicKey {
 557                 $contents.signing_pubkey()
 558         }
 559 } }
 560
 561 impl Offer {
 562         offer_accessors!(self, self.contents);
 563
 564         pub(super) fn implied_chain(&self) -> ChainHash {
 565                 self.contents.implied_chain()
 566         }
 567
 568         /// Returns whether the given chain is supported by the offer.
 569         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 570                 self.contents.supports_chain(chain)
 571         }
 572
 573         /// Whether the offer has expired.
 574         #[cfg(feature = "std")]
 575         pub fn is_expired(&self) -> bool {
 576                 self.contents.is_expired()
 577         }
 578
 579         /// Whether the offer has expired given the duration since the Unix epoch.
 580         pub fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 581                 self.contents.is_expired_no_std(duration_since_epoch)
 582         }
 583
 584         /// Returns whether the given quantity is valid for the offer.
 585         pub fn is_valid_quantity(&self, quantity: u64) -> bool {
 586                 self.contents.is_valid_quantity(quantity)
 587         }
 588
 589         /// Returns whether a quantity is expected in an [`InvoiceRequest`] for the offer.
 590         ///
 591         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 592         pub fn expects_quantity(&self) -> bool {
 593                 self.contents.expects_quantity()
 594         }
 595 }
 596
 597 macro_rules! request_invoice_derived_payer_id { ($self: ident, $builder: ty) => {
 598         /// Similar to [`Offer::request_invoice`] except it:
 599         /// - derives the [`InvoiceRequest::payer_id`] such that a different key can be used for each
 600         ///   request,
 601         /// - sets [`InvoiceRequest::payer_metadata`] when [`InvoiceRequestBuilder::build`] is called
 602         ///   such that it can be used by [`Bolt12Invoice::verify`] to determine if the invoice was
 603         ///   requested using a base [`ExpandedKey`] from which the payer id was derived, and
 604         /// - includes the [`PaymentId`] encrypted in [`InvoiceRequest::payer_metadata`] so that it can
 605         ///   be used when sending the payment for the requested invoice.
 606         ///
 607         /// Useful to protect the sender's privacy.
 608         ///
 609         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 610         /// [`InvoiceRequest::payer_metadata`]: crate::offers::invoice_request::InvoiceRequest::payer_metadata
 611         /// [`Bolt12Invoice::verify`]: crate::offers::invoice::Bolt12Invoice::verify
 612         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
 613         pub fn request_invoice_deriving_payer_id<
 614                 'a, 'b, ES: Deref,
 615                 #[cfg(not(c_bindings))]
 616                 T: secp256k1::Signing
 617         >(
 618                 &'a $self, expanded_key: &ExpandedKey, entropy_source: ES,
 619                 #[cfg(not(c_bindings))]
 620                 secp_ctx: &'b Secp256k1<T>,
 621                 #[cfg(c_bindings)]
 622                 secp_ctx: &'b Secp256k1<secp256k1::All>,
 623                 payment_id: PaymentId
 624         ) -> Result<$builder, Bolt12SemanticError>
 625         where
 626                 ES::Target: EntropySource,
 627         {
 628                 if $self.offer_features().requires_unknown_bits() {
 629                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 630                 }
 631
 632                 Ok(<$builder>::deriving_payer_id($self, expanded_key, entropy_source, secp_ctx, payment_id))
 633         }
 634 } }
 635
 636 macro_rules! request_invoice_explicit_payer_id { ($self: ident, $builder: ty) => {
 637         /// Similar to [`Offer::request_invoice_deriving_payer_id`] except uses `payer_id` for the
 638         /// [`InvoiceRequest::payer_id`] instead of deriving a different key for each request.
 639         ///
 640         /// Useful for recurring payments using the same `payer_id` with different invoices.
 641         ///
 642         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
 643         pub fn request_invoice_deriving_metadata<ES: Deref>(
 644                 &$self, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 645                 payment_id: PaymentId
 646         ) -> Result<$builder, Bolt12SemanticError>
 647         where
 648                 ES::Target: EntropySource,
 649         {
 650                 if $self.offer_features().requires_unknown_bits() {
 651                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 652                 }
 653
 654                 Ok(<$builder>::deriving_metadata($self, payer_id, expanded_key, entropy_source, payment_id))
 655         }
 656
 657         /// Creates an [`InvoiceRequestBuilder`] for the offer with the given `metadata` and `payer_id`,
 658         /// which will be reflected in the `Bolt12Invoice` response.
 659         ///
 660         /// The `metadata` is useful for including information about the derivation of `payer_id` such
 661         /// that invoice response handling can be stateless. Also serves as payer-provided entropy while
 662         /// hashing in the signature calculation.
 663         ///
 664         /// This should not leak any information such as by using a simple BIP-32 derivation path.
 665         /// Otherwise, payments may be correlated.
 666         ///
 667         /// Errors if the offer contains unknown required features.
 668         ///
 669         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 670         pub fn request_invoice(
 671                 &$self, metadata: Vec<u8>, payer_id: PublicKey
 672         ) -> Result<$builder, Bolt12SemanticError> {
 673                 if $self.offer_features().requires_unknown_bits() {
 674                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 675                 }
 676
 677                 Ok(<$builder>::new($self, metadata, payer_id))
 678         }
 679 } }
 680
 681 #[cfg(not(c_bindings))]
 682 impl Offer {
 683         request_invoice_derived_payer_id!(self, InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T>);
 684         request_invoice_explicit_payer_id!(self, InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>);
 685 }
 686
 687 #[cfg(c_bindings)]
 688 impl Offer {
 689         request_invoice_derived_payer_id!(self, InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b>);
 690         request_invoice_explicit_payer_id!(self, InvoiceRequestWithExplicitPayerIdBuilder);
 691 }
 692
 693 #[cfg(test)]
 694 impl Offer {
 695         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 696                 self.contents.as_tlv_stream()
 697         }
 698 }
 699
 700 impl AsRef<[u8]> for Offer {
 701         fn as_ref(&self) -> &[u8] {
 702                 &self.bytes
 703         }
 704 }
 705
 706 impl OfferContents {
 707         pub fn chains(&self) -> Vec<ChainHash> {
 708                 self.chains.as_ref().cloned().unwrap_or_else(|| vec![self.implied_chain()])
 709         }
 710
 711         pub fn implied_chain(&self) -> ChainHash {
 712                 ChainHash::using_genesis_block(Network::Bitcoin)
 713         }
 714
 715         pub fn supports_chain(&self, chain: ChainHash) -> bool {
 716                 self.chains().contains(&chain)
 717         }
 718
 719         pub fn metadata(&self) -> Option<&Vec<u8>> {
 720                 self.metadata.as_ref().and_then(|metadata| metadata.as_bytes())
 721         }
 722
 723         pub fn amount(&self) -> Option<&Amount> {
 724                 self.amount.as_ref()
 725         }
 726
 727         pub fn description(&self) -> PrintableString {
 728                 PrintableString(&self.description)
 729         }
 730
 731         pub fn features(&self) -> &OfferFeatures {
 732                 &self.features
 733         }
 734
 735         pub fn absolute_expiry(&self) -> Option<Duration> {
 736                 self.absolute_expiry
 737         }
 738
 739         #[cfg(feature = "std")]
 740         pub(super) fn is_expired(&self) -> bool {
 741                 SystemTime::UNIX_EPOCH
 742                         .elapsed()
 743                         .map(|duration_since_epoch| self.is_expired_no_std(duration_since_epoch))
 744                         .unwrap_or(false)
 745         }
 746
 747         pub(super) fn is_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 748                 self.absolute_expiry
 749                         .map(|absolute_expiry| duration_since_epoch > absolute_expiry)
 750                         .unwrap_or(false)
 751         }
 752
 753         pub fn issuer(&self) -> Option<PrintableString> {
 754                 self.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 755         }
 756
 757         pub fn paths(&self) -> &[BlindedPath] {
 758                 self.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 759         }
 760
 761         pub(super) fn check_amount_msats_for_quantity(
 762                 &self, amount_msats: Option<u64>, quantity: Option<u64>
 763         ) -> Result<(), Bolt12SemanticError> {
 764                 let offer_amount_msats = match self.amount {
 765                         None => 0,
 766                         Some(Amount::Bitcoin { amount_msats }) => amount_msats,
 767                         Some(Amount::Currency { .. }) => return Err(Bolt12SemanticError::UnsupportedCurrency),
 768                 };
 769
 770                 if !self.expects_quantity() || quantity.is_some() {
 771                         let expected_amount_msats = offer_amount_msats.checked_mul(quantity.unwrap_or(1))
 772                                 .ok_or(Bolt12SemanticError::InvalidAmount)?;
 773                         let amount_msats = amount_msats.unwrap_or(expected_amount_msats);
 774
 775                         if amount_msats < expected_amount_msats {
 776                                 return Err(Bolt12SemanticError::InsufficientAmount);
 777                         }
 778
 779                         if amount_msats > MAX_VALUE_MSAT {
 780                                 return Err(Bolt12SemanticError::InvalidAmount);
 781                         }
 782                 }
 783
 784                 Ok(())
 785         }
 786
 787         pub fn supported_quantity(&self) -> Quantity {
 788                 self.supported_quantity
 789         }
 790
 791         pub(super) fn check_quantity(&self, quantity: Option<u64>) -> Result<(), Bolt12SemanticError> {
 792                 let expects_quantity = self.expects_quantity();
 793                 match quantity {
 794                         None if expects_quantity => Err(Bolt12SemanticError::MissingQuantity),
 795                         Some(_) if !expects_quantity => Err(Bolt12SemanticError::UnexpectedQuantity),
 796                         Some(quantity) if !self.is_valid_quantity(quantity) => {
 797                                 Err(Bolt12SemanticError::InvalidQuantity)
 798                         },
 799                         _ => Ok(()),
 800                 }
 801         }
 802
 803         fn is_valid_quantity(&self, quantity: u64) -> bool {
 804                 match self.supported_quantity {
 805                         Quantity::Bounded(n) => quantity <= n.get(),
 806                         Quantity::Unbounded => quantity > 0,
 807                         Quantity::One => quantity == 1,
 808                 }
 809         }
 810
 811         fn expects_quantity(&self) -> bool {
 812                 match self.supported_quantity {
 813                         Quantity::Bounded(_) => true,
 814                         Quantity::Unbounded => true,
 815                         Quantity::One => false,
 816                 }
 817         }
 818
 819         pub(super) fn signing_pubkey(&self) -> PublicKey {
 820                 self.signing_pubkey
 821         }
 822
 823         /// Verifies that the offer metadata was produced from the offer in the TLV stream.
 824         pub(super) fn verify<T: secp256k1::Signing>(
 825                 &self, bytes: &[u8], key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 826         ) -> Result<Option<KeyPair>, ()> {
 827                 match self.metadata() {
 828                         Some(metadata) => {
 829                                 let tlv_stream = TlvStream::new(bytes).range(OFFER_TYPES).filter(|record| {
 830                                         match record.r#type {
 831                                                 OFFER_METADATA_TYPE => false,
 832                                                 OFFER_NODE_ID_TYPE => {
 833                                                         !self.metadata.as_ref().unwrap().derives_recipient_keys()
 834                                                 },
 835                                                 _ => true,
 836                                         }
 837                                 });
 838                                 signer::verify_recipient_metadata(
 839                                         metadata, key, IV_BYTES, self.signing_pubkey(), tlv_stream, secp_ctx
 840                                 )
 841                         },
 842                         None => Err(()),
 843                 }
 844         }
 845
 846         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
 847                 let (currency, amount) = match &self.amount {
 848                         None => (None, None),
 849                         Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)),
 850                         Some(Amount::Currency { iso4217_code, amount }) => (
 851                                 Some(iso4217_code), Some(*amount)
 852                         ),
 853                 };
 854
 855                 let features = {
 856                         if self.features == OfferFeatures::empty() { None } else { Some(&self.features) }
 857                 };
 858
 859                 OfferTlvStreamRef {
 860                         chains: self.chains.as_ref(),
 861                         metadata: self.metadata(),
 862                         currency,
 863                         amount,
 864                         description: Some(&self.description),
 865                         features,
 866                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 867                         paths: self.paths.as_ref(),
 868                         issuer: self.issuer.as_ref(),
 869                         quantity_max: self.supported_quantity.to_tlv_record(),
 870                         node_id: Some(&self.signing_pubkey),
 871                 }
 872         }
 873 }
 874
 875 impl Writeable for Offer {
 876         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 877                 WithoutLength(&self.bytes).write(writer)
 878         }
 879 }
 880
 881 impl Writeable for OfferContents {
 882         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 883                 self.as_tlv_stream().write(writer)
 884         }
 885 }
 886
 887 /// The minimum amount required for an item in an [`Offer`], denominated in either bitcoin or
 888 /// another currency.
 889 #[derive(Clone, Debug, PartialEq)]
 890 pub enum Amount {
 891         /// An amount of bitcoin.
 892         Bitcoin {
 893                 /// The amount in millisatoshi.
 894                 amount_msats: u64,
 895         },
 896         /// An amount of currency specified using ISO 4712.
 897         Currency {
 898                 /// The currency that the amount is denominated in.
 899                 iso4217_code: CurrencyCode,
 900                 /// The amount in the currency unit adjusted by the ISO 4712 exponent (e.g., USD cents).
 901                 amount: u64,
 902         },
 903 }
 904
 905 /// An ISO 4712 three-letter currency code (e.g., USD).
 906 pub type CurrencyCode = [u8; 3];
 907
 908 /// Quantity of items supported by an [`Offer`].
 909 #[derive(Clone, Copy, Debug, PartialEq)]
 910 pub enum Quantity {
 911         /// Up to a specific number of items (inclusive). Use when more than one item can be requested
 912         /// but is limited (e.g., because of per customer or inventory limits).
 913         ///
 914         /// May be used with `NonZeroU64::new(1)` but prefer to use [`Quantity::One`] if only one item
 915         /// is supported.
 916         Bounded(NonZeroU64),
 917         /// One or more items. Use when more than one item can be requested without any limit.
 918         Unbounded,
 919         /// Only one item. Use when only a single item can be requested.
 920         One,
 921 }
 922
 923 impl Quantity {
 924         fn to_tlv_record(&self) -> Option<u64> {
 925                 match self {
 926                         Quantity::Bounded(n) => Some(n.get()),
 927                         Quantity::Unbounded => Some(0),
 928                         Quantity::One => None,
 929                 }
 930         }
 931 }
 932
 933 /// Valid type range for offer TLV records.
 934 pub(super) const OFFER_TYPES: core::ops::Range<u64> = 1..80;
 935
 936 /// TLV record type for [`Offer::metadata`].
 937 const OFFER_METADATA_TYPE: u64 = 4;
 938
 939 /// TLV record type for [`Offer::signing_pubkey`].
 940 const OFFER_NODE_ID_TYPE: u64 = 22;
 941
 942 tlv_stream!(OfferTlvStream, OfferTlvStreamRef, OFFER_TYPES, {
 943         (2, chains: (Vec<ChainHash>, WithoutLength)),
 944         (OFFER_METADATA_TYPE, metadata: (Vec<u8>, WithoutLength)),
 945         (6, currency: CurrencyCode),
 946         (8, amount: (u64, HighZeroBytesDroppedBigSize)),
 947         (10, description: (String, WithoutLength)),
 948         (12, features: (OfferFeatures, WithoutLength)),
 949         (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)),
 950         (16, paths: (Vec<BlindedPath>, WithoutLength)),
 951         (18, issuer: (String, WithoutLength)),
 952         (20, quantity_max: (u64, HighZeroBytesDroppedBigSize)),
 953         (OFFER_NODE_ID_TYPE, node_id: PublicKey),
 954 });
 955
 956 impl Bech32Encode for Offer {
 957         const BECH32_HRP: &'static str = "lno";
 958 }
 959
 960 impl FromStr for Offer {
 961         type Err = Bolt12ParseError;
 962
 963         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 964                 Self::from_bech32_str(s)
 965         }
 966 }
 967
 968 impl TryFrom<Vec<u8>> for Offer {
 969         type Error = Bolt12ParseError;
 970
 971         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 972                 let offer = ParsedMessage::<OfferTlvStream>::try_from(bytes)?;
 973                 let ParsedMessage { bytes, tlv_stream } = offer;
 974                 let contents = OfferContents::try_from(tlv_stream)?;
 975                 Ok(Offer { bytes, contents })
 976         }
 977 }
 978
 979 impl TryFrom<OfferTlvStream> for OfferContents {
 980         type Error = Bolt12SemanticError;
 981
 982         fn try_from(tlv_stream: OfferTlvStream) -> Result<Self, Self::Error> {
 983                 let OfferTlvStream {
 984                         chains, metadata, currency, amount, description, features, absolute_expiry, paths,
 985                         issuer, quantity_max, node_id,
 986                 } = tlv_stream;
 987
 988                 let metadata = metadata.map(|metadata| Metadata::Bytes(metadata));
 989
 990                 let amount = match (currency, amount) {
 991                         (None, None) => None,
 992                         (None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
 993                                 return Err(Bolt12SemanticError::InvalidAmount);
 994                         },
 995                         (None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
 996                         (Some(_), None) => return Err(Bolt12SemanticError::MissingAmount),
 997                         (Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),
 998                 };
 999
1000                 let description = match description {
1001                         None => return Err(Bolt12SemanticError::MissingDescription),
1002                         Some(description) => description,
1003                 };
1004
1005                 let features = features.unwrap_or_else(OfferFeatures::empty);
1006
1007                 let absolute_expiry = absolute_expiry
1008                         .map(|seconds_from_epoch| Duration::from_secs(seconds_from_epoch));
1009
1010                 let supported_quantity = match quantity_max {
1011                         None => Quantity::One,
1012                         Some(0) => Quantity::Unbounded,
1013                         Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
1014                 };
1015
1016                 let signing_pubkey = match node_id {
1017                         None => return Err(Bolt12SemanticError::MissingSigningPubkey),
1018                         Some(node_id) => node_id,
1019                 };
1020
1021                 Ok(OfferContents {
1022                         chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
1023                         supported_quantity, signing_pubkey,
1024                 })
1025         }
1026 }
1027
1028 impl core::fmt::Display for Offer {
1029         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
1030                 self.fmt_bech32_str(f)
1031         }
1032 }
1033
1034 #[cfg(test)]
1035 mod tests {
1036         use super::{Amount, Offer, OfferTlvStreamRef, Quantity};
1037         #[cfg(not(c_bindings))]
1038         use {
1039                 super::OfferBuilder,
1040         };
1041         #[cfg(c_bindings)]
1042         use {
1043                 super::OfferWithExplicitMetadataBuilder as OfferBuilder,
1044         };
1045
1046         use bitcoin::blockdata::constants::ChainHash;
1047         use bitcoin::network::constants::Network;
1048         use bitcoin::secp256k1::Secp256k1;
1049         use core::convert::TryFrom;
1050         use core::num::NonZeroU64;
1051         use core::time::Duration;
1052         use crate::blinded_path::{BlindedHop, BlindedPath};
1053         use crate::sign::KeyMaterial;
1054         use crate::ln::features::OfferFeatures;
1055         use crate::ln::inbound_payment::ExpandedKey;
1056         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
1057         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
1058         use crate::offers::test_utils::*;
1059         use crate::util::ser::{BigSize, Writeable};
1060         use crate::util::string::PrintableString;
1061
1062         #[test]
1063         fn builds_offer_with_defaults() {
1064                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1065
1066                 let mut buffer = Vec::new();
1067                 offer.write(&mut buffer).unwrap();
1068
1069                 assert_eq!(offer.bytes, buffer.as_slice());
1070                 assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
1071                 assert!(offer.supports_chain(ChainHash::using_genesis_block(Network::Bitcoin)));
1072                 assert_eq!(offer.metadata(), None);
1073                 assert_eq!(offer.amount(), None);
1074                 assert_eq!(offer.description(), PrintableString("foo"));
1075                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1076                 assert_eq!(offer.absolute_expiry(), None);
1077                 #[cfg(feature = "std")]
1078                 assert!(!offer.is_expired());
1079                 assert_eq!(offer.paths(), &[]);
1080                 assert_eq!(offer.issuer(), None);
1081                 assert_eq!(offer.supported_quantity(), Quantity::One);
1082                 assert_eq!(offer.signing_pubkey(), pubkey(42));
1083
1084                 assert_eq!(
1085                         offer.as_tlv_stream(),
1086                         OfferTlvStreamRef {
1087                                 chains: None,
1088                                 metadata: None,
1089                                 currency: None,
1090                                 amount: None,
1091                                 description: Some(&String::from("foo")),
1092                                 features: None,
1093                                 absolute_expiry: None,
1094                                 paths: None,
1095                                 issuer: None,
1096                                 quantity_max: None,
1097                                 node_id: Some(&pubkey(42)),
1098                         },
1099                 );
1100
1101                 if let Err(e) = Offer::try_from(buffer) {
1102                         panic!("error parsing offer: {:?}", e);
1103                 }
1104         }
1105
1106         #[test]
1107         fn builds_offer_with_chains() {
1108                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
1109                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
1110
1111                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1112                         .chain(Network::Bitcoin)
1113                         .build()
1114                         .unwrap();
1115                 assert!(offer.supports_chain(mainnet));
1116                 assert_eq!(offer.chains(), vec![mainnet]);
1117                 assert_eq!(offer.as_tlv_stream().chains, None);
1118
1119                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1120                         .chain(Network::Testnet)
1121                         .build()
1122                         .unwrap();
1123                 assert!(offer.supports_chain(testnet));
1124                 assert_eq!(offer.chains(), vec![testnet]);
1125                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1126
1127                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1128                         .chain(Network::Testnet)
1129                         .chain(Network::Testnet)
1130                         .build()
1131                         .unwrap();
1132                 assert!(offer.supports_chain(testnet));
1133                 assert_eq!(offer.chains(), vec![testnet]);
1134                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
1135
1136                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1137                         .chain(Network::Bitcoin)
1138                         .chain(Network::Testnet)
1139                         .build()
1140                         .unwrap();
1141                 assert!(offer.supports_chain(mainnet));
1142                 assert!(offer.supports_chain(testnet));
1143                 assert_eq!(offer.chains(), vec![mainnet, testnet]);
1144                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet]));
1145         }
1146
1147         #[test]
1148         fn builds_offer_with_metadata() {
1149                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1150                         .metadata(vec![42; 32]).unwrap()
1151                         .build()
1152                         .unwrap();
1153                 assert_eq!(offer.metadata(), Some(&vec![42; 32]));
1154                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![42; 32]));
1155
1156                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1157                         .metadata(vec![42; 32]).unwrap()
1158                         .metadata(vec![43; 32]).unwrap()
1159                         .build()
1160                         .unwrap();
1161                 assert_eq!(offer.metadata(), Some(&vec![43; 32]));
1162                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![43; 32]));
1163         }
1164
1165         #[test]
1166         fn builds_offer_with_metadata_derived() {
1167                 let desc = "foo".to_string();
1168                 let node_id = recipient_pubkey();
1169                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1170                 let entropy = FixedEntropy {};
1171                 let secp_ctx = Secp256k1::new();
1172
1173                 #[cfg(c_bindings)]
1174                 use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
1175                 let offer = OfferBuilder
1176                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1177                         .amount_msats(1000)
1178                         .build().unwrap();
1179                 assert_eq!(offer.signing_pubkey(), node_id);
1180
1181                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1182                         .build().unwrap()
1183                         .sign(payer_sign).unwrap();
1184                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1185
1186                 // Fails verification with altered offer field
1187                 let mut tlv_stream = offer.as_tlv_stream();
1188                 tlv_stream.amount = Some(100);
1189
1190                 let mut encoded_offer = Vec::new();
1191                 tlv_stream.write(&mut encoded_offer).unwrap();
1192
1193                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1194                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1195                         .build().unwrap()
1196                         .sign(payer_sign).unwrap();
1197                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1198
1199                 // Fails verification with altered metadata
1200                 let mut tlv_stream = offer.as_tlv_stream();
1201                 let metadata = tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1202                 tlv_stream.metadata = Some(&metadata);
1203
1204                 let mut encoded_offer = Vec::new();
1205                 tlv_stream.write(&mut encoded_offer).unwrap();
1206
1207                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1208                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1209                         .build().unwrap()
1210                         .sign(payer_sign).unwrap();
1211                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1212         }
1213
1214         #[test]
1215         fn builds_offer_with_derived_signing_pubkey() {
1216                 let desc = "foo".to_string();
1217                 let node_id = recipient_pubkey();
1218                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1219                 let entropy = FixedEntropy {};
1220                 let secp_ctx = Secp256k1::new();
1221
1222                 let blinded_path = BlindedPath {
1223                         introduction_node_id: pubkey(40),
1224                         blinding_point: pubkey(41),
1225                         blinded_hops: vec![
1226                                 BlindedHop { blinded_node_id: pubkey(42), encrypted_payload: vec![0; 43] },
1227                                 BlindedHop { blinded_node_id: node_id, encrypted_payload: vec![0; 44] },
1228                         ],
1229                 };
1230
1231                 #[cfg(c_bindings)]
1232                 use super::OfferWithDerivedMetadataBuilder as OfferBuilder;
1233                 let offer = OfferBuilder
1234                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1235                         .amount_msats(1000)
1236                         .path(blinded_path)
1237                         .build().unwrap();
1238                 assert_ne!(offer.signing_pubkey(), node_id);
1239
1240                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1241                         .build().unwrap()
1242                         .sign(payer_sign).unwrap();
1243                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1244
1245                 // Fails verification with altered offer field
1246                 let mut tlv_stream = offer.as_tlv_stream();
1247                 tlv_stream.amount = Some(100);
1248
1249                 let mut encoded_offer = Vec::new();
1250                 tlv_stream.write(&mut encoded_offer).unwrap();
1251
1252                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1253                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1254                         .build().unwrap()
1255                         .sign(payer_sign).unwrap();
1256                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1257
1258                 // Fails verification with altered signing pubkey
1259                 let mut tlv_stream = offer.as_tlv_stream();
1260                 let signing_pubkey = pubkey(1);
1261                 tlv_stream.node_id = Some(&signing_pubkey);
1262
1263                 let mut encoded_offer = Vec::new();
1264                 tlv_stream.write(&mut encoded_offer).unwrap();
1265
1266                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1267                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1268                         .build().unwrap()
1269                         .sign(payer_sign).unwrap();
1270                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1271         }
1272
1273         #[test]
1274         fn builds_offer_with_amount() {
1275                 let bitcoin_amount = Amount::Bitcoin { amount_msats: 1000 };
1276                 let currency_amount = Amount::Currency { iso4217_code: *b"USD", amount: 10 };
1277
1278                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1279                         .amount_msats(1000)
1280                         .build()
1281                         .unwrap();
1282                 let tlv_stream = offer.as_tlv_stream();
1283                 assert_eq!(offer.amount(), Some(&bitcoin_amount));
1284                 assert_eq!(tlv_stream.amount, Some(1000));
1285                 assert_eq!(tlv_stream.currency, None);
1286
1287                 #[cfg(not(c_bindings))]
1288                 let builder = OfferBuilder::new("foo".into(), pubkey(42))
1289                         .amount(currency_amount.clone());
1290                 #[cfg(c_bindings)]
1291                 let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
1292                 #[cfg(c_bindings)]
1293                 builder.amount(currency_amount.clone());
1294                 let tlv_stream = builder.offer.as_tlv_stream();
1295                 assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
1296                 assert_eq!(tlv_stream.amount, Some(10));
1297                 assert_eq!(tlv_stream.currency, Some(b"USD"));
1298                 match builder.build() {
1299                         Ok(_) => panic!("expected error"),
1300                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedCurrency),
1301                 }
1302
1303                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1304                         .amount(currency_amount.clone())
1305                         .amount(bitcoin_amount.clone())
1306                         .build()
1307                         .unwrap();
1308                 let tlv_stream = offer.as_tlv_stream();
1309                 assert_eq!(tlv_stream.amount, Some(1000));
1310                 assert_eq!(tlv_stream.currency, None);
1311
1312                 let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
1313                 match OfferBuilder::new("foo".into(), pubkey(42)).amount(invalid_amount).build() {
1314                         Ok(_) => panic!("expected error"),
1315                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1316                 }
1317         }
1318
1319         #[test]
1320         fn builds_offer_with_features() {
1321                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1322                         .features_unchecked(OfferFeatures::unknown())
1323                         .build()
1324                         .unwrap();
1325                 assert_eq!(offer.offer_features(), &OfferFeatures::unknown());
1326                 assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
1327
1328                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1329                         .features_unchecked(OfferFeatures::unknown())
1330                         .features_unchecked(OfferFeatures::empty())
1331                         .build()
1332                         .unwrap();
1333                 assert_eq!(offer.offer_features(), &OfferFeatures::empty());
1334                 assert_eq!(offer.as_tlv_stream().features, None);
1335         }
1336
1337         #[test]
1338         fn builds_offer_with_absolute_expiry() {
1339                 let future_expiry = Duration::from_secs(u64::max_value());
1340                 let past_expiry = Duration::from_secs(0);
1341                 let now = future_expiry - Duration::from_secs(1_000);
1342
1343                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1344                         .absolute_expiry(future_expiry)
1345                         .build()
1346                         .unwrap();
1347                 #[cfg(feature = "std")]
1348                 assert!(!offer.is_expired());
1349                 assert!(!offer.is_expired_no_std(now));
1350                 assert_eq!(offer.absolute_expiry(), Some(future_expiry));
1351                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
1352
1353                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1354                         .absolute_expiry(future_expiry)
1355                         .absolute_expiry(past_expiry)
1356                         .build()
1357                         .unwrap();
1358                 #[cfg(feature = "std")]
1359                 assert!(offer.is_expired());
1360                 assert!(offer.is_expired_no_std(now));
1361                 assert_eq!(offer.absolute_expiry(), Some(past_expiry));
1362                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
1363         }
1364
1365         #[test]
1366         fn builds_offer_with_paths() {
1367                 let paths = vec![
1368                         BlindedPath {
1369                                 introduction_node_id: pubkey(40),
1370                                 blinding_point: pubkey(41),
1371                                 blinded_hops: vec![
1372                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1373                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1374                                 ],
1375                         },
1376                         BlindedPath {
1377                                 introduction_node_id: pubkey(40),
1378                                 blinding_point: pubkey(41),
1379                                 blinded_hops: vec![
1380                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1381                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1382                                 ],
1383                         },
1384                 ];
1385
1386                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1387                         .path(paths[0].clone())
1388                         .path(paths[1].clone())
1389                         .build()
1390                         .unwrap();
1391                 let tlv_stream = offer.as_tlv_stream();
1392                 assert_eq!(offer.paths(), paths.as_slice());
1393                 assert_eq!(offer.signing_pubkey(), pubkey(42));
1394                 assert_ne!(pubkey(42), pubkey(44));
1395                 assert_eq!(tlv_stream.paths, Some(&paths));
1396                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
1397         }
1398
1399         #[test]
1400         fn builds_offer_with_issuer() {
1401                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1402                         .issuer("bar".into())
1403                         .build()
1404                         .unwrap();
1405                 assert_eq!(offer.issuer(), Some(PrintableString("bar")));
1406                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("bar")));
1407
1408                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1409                         .issuer("bar".into())
1410                         .issuer("baz".into())
1411                         .build()
1412                         .unwrap();
1413                 assert_eq!(offer.issuer(), Some(PrintableString("baz")));
1414                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("baz")));
1415         }
1416
1417         #[test]
1418         fn builds_offer_with_supported_quantity() {
1419                 let one = NonZeroU64::new(1).unwrap();
1420                 let ten = NonZeroU64::new(10).unwrap();
1421
1422                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1423                         .supported_quantity(Quantity::One)
1424                         .build()
1425                         .unwrap();
1426                 let tlv_stream = offer.as_tlv_stream();
1427                 assert_eq!(offer.supported_quantity(), Quantity::One);
1428                 assert_eq!(tlv_stream.quantity_max, None);
1429
1430                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1431                         .supported_quantity(Quantity::Unbounded)
1432                         .build()
1433                         .unwrap();
1434                 let tlv_stream = offer.as_tlv_stream();
1435                 assert_eq!(offer.supported_quantity(), Quantity::Unbounded);
1436                 assert_eq!(tlv_stream.quantity_max, Some(0));
1437
1438                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1439                         .supported_quantity(Quantity::Bounded(ten))
1440                         .build()
1441                         .unwrap();
1442                 let tlv_stream = offer.as_tlv_stream();
1443                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(ten));
1444                 assert_eq!(tlv_stream.quantity_max, Some(10));
1445
1446                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1447                         .supported_quantity(Quantity::Bounded(one))
1448                         .build()
1449                         .unwrap();
1450                 let tlv_stream = offer.as_tlv_stream();
1451                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(one));
1452                 assert_eq!(tlv_stream.quantity_max, Some(1));
1453
1454                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1455                         .supported_quantity(Quantity::Bounded(ten))
1456                         .supported_quantity(Quantity::One)
1457                         .build()
1458                         .unwrap();
1459                 let tlv_stream = offer.as_tlv_stream();
1460                 assert_eq!(offer.supported_quantity(), Quantity::One);
1461                 assert_eq!(tlv_stream.quantity_max, None);
1462         }
1463
1464         #[test]
1465         fn fails_requesting_invoice_with_unknown_required_features() {
1466                 match OfferBuilder::new("foo".into(), pubkey(42))
1467                         .features_unchecked(OfferFeatures::unknown())
1468                         .build().unwrap()
1469                         .request_invoice(vec![1; 32], pubkey(43))
1470                 {
1471                         Ok(_) => panic!("expected error"),
1472                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1473                 }
1474         }
1475
1476         #[test]
1477         fn parses_offer_with_chains() {
1478                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1479                         .chain(Network::Bitcoin)
1480                         .chain(Network::Testnet)
1481                         .build()
1482                         .unwrap();
1483                 if let Err(e) = offer.to_string().parse::<Offer>() {
1484                         panic!("error parsing offer: {:?}", e);
1485                 }
1486         }
1487
1488         #[test]
1489         fn parses_offer_with_amount() {
1490                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1491                         .amount(Amount::Bitcoin { amount_msats: 1000 })
1492                         .build()
1493                         .unwrap();
1494                 if let Err(e) = offer.to_string().parse::<Offer>() {
1495                         panic!("error parsing offer: {:?}", e);
1496                 }
1497
1498                 let mut tlv_stream = offer.as_tlv_stream();
1499                 tlv_stream.amount = Some(1000);
1500                 tlv_stream.currency = Some(b"USD");
1501
1502                 let mut encoded_offer = Vec::new();
1503                 tlv_stream.write(&mut encoded_offer).unwrap();
1504
1505                 if let Err(e) = Offer::try_from(encoded_offer) {
1506                         panic!("error parsing offer: {:?}", e);
1507                 }
1508
1509                 let mut tlv_stream = offer.as_tlv_stream();
1510                 tlv_stream.amount = None;
1511                 tlv_stream.currency = Some(b"USD");
1512
1513                 let mut encoded_offer = Vec::new();
1514                 tlv_stream.write(&mut encoded_offer).unwrap();
1515
1516                 match Offer::try_from(encoded_offer) {
1517                         Ok(_) => panic!("expected error"),
1518                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1519                 }
1520
1521                 let mut tlv_stream = offer.as_tlv_stream();
1522                 tlv_stream.amount = Some(MAX_VALUE_MSAT + 1);
1523                 tlv_stream.currency = None;
1524
1525                 let mut encoded_offer = Vec::new();
1526                 tlv_stream.write(&mut encoded_offer).unwrap();
1527
1528                 match Offer::try_from(encoded_offer) {
1529                         Ok(_) => panic!("expected error"),
1530                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1531                 }
1532         }
1533
1534         #[test]
1535         fn parses_offer_with_description() {
1536                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1537                 if let Err(e) = offer.to_string().parse::<Offer>() {
1538                         panic!("error parsing offer: {:?}", e);
1539                 }
1540
1541                 let mut tlv_stream = offer.as_tlv_stream();
1542                 tlv_stream.description = None;
1543
1544                 let mut encoded_offer = Vec::new();
1545                 tlv_stream.write(&mut encoded_offer).unwrap();
1546
1547                 match Offer::try_from(encoded_offer) {
1548                         Ok(_) => panic!("expected error"),
1549                         Err(e) => {
1550                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription));
1551                         },
1552                 }
1553         }
1554
1555         #[test]
1556         fn parses_offer_with_paths() {
1557                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1558                         .path(BlindedPath {
1559                                 introduction_node_id: pubkey(40),
1560                                 blinding_point: pubkey(41),
1561                                 blinded_hops: vec![
1562                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1563                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1564                                 ],
1565                         })
1566                         .path(BlindedPath {
1567                                 introduction_node_id: pubkey(40),
1568                                 blinding_point: pubkey(41),
1569                                 blinded_hops: vec![
1570                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1571                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1572                                 ],
1573                         })
1574                         .build()
1575                         .unwrap();
1576                 if let Err(e) = offer.to_string().parse::<Offer>() {
1577                         panic!("error parsing offer: {:?}", e);
1578                 }
1579
1580                 let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
1581                 builder.offer.paths = Some(vec![]);
1582
1583                 let offer = builder.build().unwrap();
1584                 if let Err(e) = offer.to_string().parse::<Offer>() {
1585                         panic!("error parsing offer: {:?}", e);
1586                 }
1587         }
1588
1589         #[test]
1590         fn parses_offer_with_quantity() {
1591                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1592                         .supported_quantity(Quantity::One)
1593                         .build()
1594                         .unwrap();
1595                 if let Err(e) = offer.to_string().parse::<Offer>() {
1596                         panic!("error parsing offer: {:?}", e);
1597                 }
1598
1599                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1600                         .supported_quantity(Quantity::Unbounded)
1601                         .build()
1602                         .unwrap();
1603                 if let Err(e) = offer.to_string().parse::<Offer>() {
1604                         panic!("error parsing offer: {:?}", e);
1605                 }
1606
1607                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1608                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(10).unwrap()))
1609                         .build()
1610                         .unwrap();
1611                 if let Err(e) = offer.to_string().parse::<Offer>() {
1612                         panic!("error parsing offer: {:?}", e);
1613                 }
1614
1615                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1616                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(1).unwrap()))
1617                         .build()
1618                         .unwrap();
1619                 if let Err(e) = offer.to_string().parse::<Offer>() {
1620                         panic!("error parsing offer: {:?}", e);
1621                 }
1622         }
1623
1624         #[test]
1625         fn parses_offer_with_node_id() {
1626                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1627                 if let Err(e) = offer.to_string().parse::<Offer>() {
1628                         panic!("error parsing offer: {:?}", e);
1629                 }
1630
1631                 let mut tlv_stream = offer.as_tlv_stream();
1632                 tlv_stream.node_id = None;
1633
1634                 let mut encoded_offer = Vec::new();
1635                 tlv_stream.write(&mut encoded_offer).unwrap();
1636
1637                 match Offer::try_from(encoded_offer) {
1638                         Ok(_) => panic!("expected error"),
1639                         Err(e) => {
1640                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1641                         },
1642                 }
1643         }
1644
1645         #[test]
1646         fn fails_parsing_offer_with_extra_tlv_records() {
1647                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1648
1649                 let mut encoded_offer = Vec::new();
1650                 offer.write(&mut encoded_offer).unwrap();
1651                 BigSize(80).write(&mut encoded_offer).unwrap();
1652                 BigSize(32).write(&mut encoded_offer).unwrap();
1653                 [42u8; 32].write(&mut encoded_offer).unwrap();
1654
1655                 match Offer::try_from(encoded_offer) {
1656                         Ok(_) => panic!("expected error"),
1657                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1658                 }
1659         }
1660 }
1661
1662 #[cfg(test)]
1663 mod bolt12_tests {
1664         use super::{Bolt12ParseError, Bolt12SemanticError, Offer};
1665         use crate::ln::msgs::DecodeError;
1666
1667         #[test]
1668         fn parses_bech32_encoded_offers() {
1669                 let offers = [
1670                         // Minimal bolt12 offer
1671                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1672
1673                         // for testnet
1674                         "lno1qgsyxjtl6luzd9t3pr62xr7eemp6awnejusgf6gw45q75vcfqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1675
1676                         // for bitcoin (redundant)
1677                         "lno1qgsxlc5vp2m0rvmjcxn2y34wv0m5lyc7sdj7zksgn35dvxgqqqqqqqq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1678
1679                         // for bitcoin or liquidv1
1680                         "lno1qfqpge38tqmzyrdjj3x2qkdr5y80dlfw56ztq6yd9sme995g3gsxqqm0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq9qc4r9wd6zqan9vd6x7unnzcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1681
1682                         // with metadata
1683                         "lno1qsgqqqqqqqqqqqqqqqqqqqqqqqqqqzsv23jhxapqwejkxar0wfe3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1684
1685                         // with amount
1686                         "lno1pqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1687
1688                         // with currency
1689                         "lno1qcp4256ypqpzwyq2p32x2um5ypmx2cm5dae8x93pqthvwfzadd7jejes8q9lhc4rvjxd022zv5l44g6qah82ru5rdpnpj",
1690
1691                         // with expiry
1692                         "lno1pgx9getnwss8vetrw3hhyucwq3ay997czcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese",
1693
1694                         // with issuer
1695                         "lno1pgx9getnwss8vetrw3hhyucjy358garswvaz7tmzdak8gvfj9ehhyeeqgf85c4p3xgsxjmnyw4ehgunfv4e3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1696
1697                         // with quantity
1698                         "lno1pgx9getnwss8vetrw3hhyuc5qyz3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1699
1700                         // with unlimited (or unknown) quantity
1701                         "lno1pgx9getnwss8vetrw3hhyuc5qqtzzqhwcuj966ma9n9nqwqtl032xeyv6755yeflt235pmww58egx6rxry",
1702
1703                         // with single quantity (weird but valid)
1704                         "lno1pgx9getnwss8vetrw3hhyuc5qyq3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1705
1706                         // with feature
1707                         "lno1pgx9getnwss8vetrw3hhyucvp5yqqqqqqqqqqqqqqqqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg",
1708
1709                         // with blinded path via Bob (0x424242...), blinding 020202...
1710                         "lno1pgx9getnwss8vetrw3hhyucs5ypjgef743p5fzqq9nqxh0ah7y87rzv3ud0eleps9kl2d5348hq2k8qzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgqpqqqqqqqqqqqqqqqqqqqqqqqqqqqzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqqzq3zyg3zyg3zyg3vggzamrjghtt05kvkvpcp0a79gmy3nt6jsn98ad2xs8de6sl9qmgvcvs",
1711
1712                         // ... and with second blinded path via Carol (0x434343...), blinding 020202...
1713                         "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",
1714
1715                         // unknown odd field
1716                         "lno1pgx9getnwss8vetrw3hhyuckyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxfppf5x2mrvdamk7unvvs",
1717                 ];
1718                 for encoded_offer in &offers {
1719                         if let Err(e) = encoded_offer.parse::<Offer>() {
1720                                 panic!("Invalid offer ({:?}): {}", e, encoded_offer);
1721                         }
1722                 }
1723         }
1724
1725         #[test]
1726         fn fails_parsing_bech32_encoded_offers() {
1727                 // Malformed: fields out of order
1728                 assert_eq!(
1729                         "lno1zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszpgz5znzfgdzs".parse::<Offer>(),
1730                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1731                 );
1732
1733                 // Malformed: unknown even TLV type 78
1734                 assert_eq!(
1735                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpysgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1736                         Err(Bolt12ParseError::Decode(DecodeError::UnknownRequiredFeature)),
1737                 );
1738
1739                 // Malformed: empty
1740                 assert_eq!(
1741                         "lno1".parse::<Offer>(),
1742                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
1743                 );
1744
1745                 // Malformed: truncated at type
1746                 assert_eq!(
1747                         "lno1pg".parse::<Offer>(),
1748                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1749                 );
1750
1751                 // Malformed: truncated in length
1752                 assert_eq!(
1753                         "lno1pt7s".parse::<Offer>(),
1754                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1755                 );
1756
1757                 // Malformed: truncated after length
1758                 assert_eq!(
1759                         "lno1pgpq".parse::<Offer>(),
1760                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1761                 );
1762
1763                 // Malformed: truncated in description
1764                 assert_eq!(
1765                         "lno1pgpyz".parse::<Offer>(),
1766                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1767                 );
1768
1769                 // Malformed: invalid offer_chains length
1770                 assert_eq!(
1771                         "lno1qgqszzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1772                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1773                 );
1774
1775                 // Malformed: truncated currency UTF-8
1776                 assert_eq!(
1777                         "lno1qcqcqzs9g9xyjs69zcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1778                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1779                 );
1780
1781                 // Malformed: invalid currency UTF-8
1782                 assert_eq!(
1783                         "lno1qcpgqsg2q4q5cj2rg5tzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1784                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1785                 );
1786
1787                 // Malformed: truncated description UTF-8
1788                 assert_eq!(
1789                         "lno1pgqcq93pqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqy".parse::<Offer>(),
1790                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1791                 );
1792
1793                 // Malformed: invalid description UTF-8
1794                 assert_eq!(
1795                         "lno1pgpgqsgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1796                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1797                 );
1798
1799                 // Malformed: truncated offer_paths
1800                 assert_eq!(
1801                         "lno1pgz5znzfgdz3qqgpzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1802                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1803                 );
1804
1805                 // Malformed: zero num_hops in blinded_path
1806                 assert_eq!(
1807                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1808                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1809                 );
1810
1811                 // Malformed: truncated onionmsg_hop in blinded_path
1812                 assert_eq!(
1813                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgkyypqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqs".parse::<Offer>(),
1814                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1815                 );
1816
1817                 // Malformed: bad first_node_id in blinded_path
1818                 assert_eq!(
1819                         "lno1pgz5znzfgdz3qqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1820                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1821                 );
1822
1823                 // Malformed: bad blinding in blinded_path
1824                 assert_eq!(
1825                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcpqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1826                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1827                 );
1828
1829                 // Malformed: bad blinded_node_id in onionmsg_hop
1830                 assert_eq!(
1831                         "lno1pgz5znzfgdz3qqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqspqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqgqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1832                         Err(Bolt12ParseError::Decode(DecodeError::ShortRead)),
1833                 );
1834
1835                 // Malformed: truncated issuer UTF-8
1836                 assert_eq!(
1837                         "lno1pgz5znzfgdz3yqvqzcssyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqsz".parse::<Offer>(),
1838                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1839                 );
1840
1841                 // Malformed: invalid issuer UTF-8
1842                 assert_eq!(
1843                         "lno1pgz5znzfgdz3yq5qgytzzqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqg".parse::<Offer>(),
1844                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1845                 );
1846
1847                 // Malformed: invalid offer_node_id
1848                 assert_eq!(
1849                         "lno1pgz5znzfgdz3vggzqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvpsxqcrqvps".parse::<Offer>(),
1850                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1851                 );
1852
1853                 // Contains type >= 80
1854                 assert_eq!(
1855                         "lno1pgz5znzfgdz3vggzqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgpqyqszqgp9qgr0u2xq4dh3kdevrf4zg6hx8a60jv0gxe0ptgyfc6xkryqqqqqqqq".parse::<Offer>(),
1856                         Err(Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1857                 );
1858
1859                 // TODO: Resolved in spec https://github.com/lightning/bolts/pull/798/files#r1334851959
1860                 // Contains unknown feature 22
1861                 assert!(
1862                         "lno1pgx9getnwss8vetrw3hhyucvqdqqqqqkyypwa3eyt44h6txtxquqh7lz5djge4afgfjn7k4rgrkuag0jsd5xvxg".parse::<Offer>().is_ok()
1863                 );
1864
1865                 // Missing offer_description
1866                 assert_eq!(
1867                         "lno1zcss9mk8y3wkklfvevcrszlmu23kfrxh49px20665dqwmn4p72pksese".parse::<Offer>(),
1868                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingDescription)),
1869                 );
1870
1871                 // Missing offer_node_id"
1872                 assert_eq!(
1873                         "lno1pgx9getnwss8vetrw3hhyuc".parse::<Offer>(),
1874                         Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey)),
1875                 );
1876         }
1877 }