_ Git - rust-lightning/blob - lightning/src/offers/invoice_request.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 `invoice_request` messages.
  11 //!
  12 //! An [`InvoiceRequest`] can be built from a parsed [`Offer`] as an "offer to be paid". It is
  13 //! typically constructed by a customer and sent to the merchant who had published the corresponding
  14 //! offer. The recipient of the request responds with a [`Bolt12Invoice`].
  15 //!
  16 //! For an "offer for money" (e.g., refund, ATM withdrawal), where an offer doesn't exist as a
  17 //! precursor, see [`Refund`].
  18 //!
  19 //! [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
  20 //! [`Refund`]: crate::offers::refund::Refund
  21 //!
  22 //! ```
  23 //! extern crate bitcoin;
  24 //! extern crate lightning;
  25 //!
  26 //! use bitcoin::network::constants::Network;
  27 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
  28 //! use lightning::ln::features::OfferFeatures;
  29 //! use lightning::offers::invoice_request::UnsignedInvoiceRequest;
  30 //! use lightning::offers::offer::Offer;
  31 //! use lightning::util::ser::Writeable;
  32 //!
  33 //! # fn parse() -> Result<(), lightning::offers::parse::Bolt12ParseError> {
  34 //! let secp_ctx = Secp256k1::new();
  35 //! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32])?);
  36 //! let pubkey = PublicKey::from(keys);
  37 //! let mut buffer = Vec::new();
  38 //!
  39 //! # use lightning::offers::invoice_request::{ExplicitPayerId, InvoiceRequestBuilder};
  40 //! # <InvoiceRequestBuilder<ExplicitPayerId, _>>::from(
  41 //! "lno1qcp4256ypq"
  42 //!     .parse::<Offer>()?
  43 //!     .request_invoice(vec![42; 64], pubkey)?
  44 //! # )
  45 //!     .chain(Network::Testnet)?
  46 //!     .amount_msats(1000)?
  47 //!     .quantity(5)?
  48 //!     .payer_note("foo".to_string())
  49 //!     .build()?
  50 //!     .sign(|message: &UnsignedInvoiceRequest|
  51 //!         Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
  52 //!     )
  53 //!     .expect("failed verifying signature")
  54 //!     .write(&mut buffer)
  55 //!     .unwrap();
  56 //! # Ok(())
  57 //! # }
  58 //! ```
  59
  60 use bitcoin::blockdata::constants::ChainHash;
  61 use bitcoin::network::constants::Network;
  62 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, self};
  63 use bitcoin::secp256k1::schnorr::Signature;
  64 use core::ops::Deref;
  65 use crate::sign::EntropySource;
  66 use crate::io;
  67 use crate::blinded_path::BlindedPath;
  68 use crate::ln::PaymentHash;
  69 use crate::ln::channelmanager::PaymentId;
  70 use crate::ln::features::InvoiceRequestFeatures;
  71 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
  72 use crate::ln::msgs::DecodeError;
  73 use crate::offers::invoice::BlindedPayInfo;
  74 use crate::offers::merkle::{SignError, SignFn, SignatureTlvStream, SignatureTlvStreamRef, TaggedHash, self};
  75 use crate::offers::offer::{Offer, OfferContents, OfferId, OfferTlvStream, OfferTlvStreamRef};
  76 use crate::offers::parse::{Bolt12ParseError, ParsedMessage, Bolt12SemanticError};
  77 use crate::offers::payer::{PayerContents, PayerTlvStream, PayerTlvStreamRef};
  78 use crate::offers::signer::{Metadata, MetadataMaterial};
  79 use crate::util::ser::{HighZeroBytesDroppedBigSize, Readable, SeekReadable, WithoutLength, Writeable, Writer};
  80 use crate::util::string::{PrintableString, UntrustedString};
  81
  82 #[cfg(not(c_bindings))]
  83 use {
  84         crate::offers::invoice::{DerivedSigningPubkey, ExplicitSigningPubkey, InvoiceBuilder},
  85 };
  86 #[cfg(c_bindings)]
  87 use {
  88         crate::offers::invoice::{InvoiceWithDerivedSigningPubkeyBuilder, InvoiceWithExplicitSigningPubkeyBuilder},
  89 };
  90
  91 #[allow(unused_imports)]
  92 use crate::prelude::*;
  93
  94 /// Tag for the hash function used when signing an [`InvoiceRequest`]'s merkle root.
  95 pub const SIGNATURE_TAG: &'static str = concat!("lightning", "invoice_request", "signature");
  96
  97 pub(super) const IV_BYTES: &[u8; IV_LEN] = b"LDK Invreq ~~~~~";
  98
  99 /// Builds an [`InvoiceRequest`] from an [`Offer`] for the "offer to be paid" flow.
 100 ///
 101 /// See [module-level documentation] for usage.
 102 ///
 103 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 104 ///
 105 /// [module-level documentation]: self
 106 pub struct InvoiceRequestBuilder<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> {
 107         offer: &'a Offer,
 108         invoice_request: InvoiceRequestContentsWithoutPayerId,
 109         payer_id: Option<PublicKey>,
 110         payer_id_strategy: core::marker::PhantomData<P>,
 111         secp_ctx: Option<&'b Secp256k1<T>>,
 112 }
 113
 114 /// Builds an [`InvoiceRequest`] from an [`Offer`] for the "offer to be paid" flow.
 115 ///
 116 /// See [module-level documentation] for usage.
 117 ///
 118 /// [module-level documentation]: self
 119 #[cfg(c_bindings)]
 120 pub struct InvoiceRequestWithExplicitPayerIdBuilder<'a, 'b> {
 121         offer: &'a Offer,
 122         invoice_request: InvoiceRequestContentsWithoutPayerId,
 123         payer_id: Option<PublicKey>,
 124         payer_id_strategy: core::marker::PhantomData<ExplicitPayerId>,
 125         secp_ctx: Option<&'b Secp256k1<secp256k1::All>>,
 126 }
 127
 128 /// Builds an [`InvoiceRequest`] from an [`Offer`] for the "offer to be paid" flow.
 129 ///
 130 /// See [module-level documentation] for usage.
 131 ///
 132 /// [module-level documentation]: self
 133 #[cfg(c_bindings)]
 134 pub struct InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b> {
 135         offer: &'a Offer,
 136         invoice_request: InvoiceRequestContentsWithoutPayerId,
 137         payer_id: Option<PublicKey>,
 138         payer_id_strategy: core::marker::PhantomData<DerivedPayerId>,
 139         secp_ctx: Option<&'b Secp256k1<secp256k1::All>>,
 140 }
 141
 142 /// Indicates how [`InvoiceRequest::payer_id`] will be set.
 143 ///
 144 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 145 pub trait PayerIdStrategy {}
 146
 147 /// [`InvoiceRequest::payer_id`] will be explicitly set.
 148 ///
 149 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 150 pub struct ExplicitPayerId {}
 151
 152 /// [`InvoiceRequest::payer_id`] will be derived.
 153 ///
 154 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 155 pub struct DerivedPayerId {}
 156
 157 impl PayerIdStrategy for ExplicitPayerId {}
 158 impl PayerIdStrategy for DerivedPayerId {}
 159
 160 macro_rules! invoice_request_explicit_payer_id_builder_methods { ($self: ident, $self_type: ty) => {
 161         #[cfg_attr(c_bindings, allow(dead_code))]
 162         pub(super) fn new(offer: &'a Offer, metadata: Vec<u8>, payer_id: PublicKey) -> Self {
 163                 Self {
 164                         offer,
 165                         invoice_request: Self::create_contents(offer, Metadata::Bytes(metadata)),
 166                         payer_id: Some(payer_id),
 167                         payer_id_strategy: core::marker::PhantomData,
 168                         secp_ctx: None,
 169                 }
 170         }
 171
 172         #[cfg_attr(c_bindings, allow(dead_code))]
 173         pub(super) fn deriving_metadata<ES: Deref>(
 174                 offer: &'a Offer, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 175                 payment_id: PaymentId,
 176         ) -> Self where ES::Target: EntropySource {
 177                 let nonce = Nonce::from_entropy_source(entropy_source);
 178                 let payment_id = Some(payment_id);
 179                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, payment_id);
 180                 let metadata = Metadata::Derived(derivation_material);
 181                 Self {
 182                         offer,
 183                         invoice_request: Self::create_contents(offer, metadata),
 184                         payer_id: Some(payer_id),
 185                         payer_id_strategy: core::marker::PhantomData,
 186                         secp_ctx: None,
 187                 }
 188         }
 189
 190         /// Builds an unsigned [`InvoiceRequest`] after checking for valid semantics. It can be signed
 191         /// by [`UnsignedInvoiceRequest::sign`].
 192         pub fn build($self: $self_type) -> Result<UnsignedInvoiceRequest, Bolt12SemanticError> {
 193                 let (unsigned_invoice_request, keys, _) = $self.build_with_checks()?;
 194                 debug_assert!(keys.is_none());
 195                 Ok(unsigned_invoice_request)
 196         }
 197 } }
 198
 199 macro_rules! invoice_request_derived_payer_id_builder_methods { (
 200         $self: ident, $self_type: ty, $secp_context: ty
 201 ) => {
 202         #[cfg_attr(c_bindings, allow(dead_code))]
 203         pub(super) fn deriving_payer_id<ES: Deref>(
 204                 offer: &'a Offer, expanded_key: &ExpandedKey, entropy_source: ES,
 205                 secp_ctx: &'b Secp256k1<$secp_context>, payment_id: PaymentId
 206         ) -> Self where ES::Target: EntropySource {
 207                 let nonce = Nonce::from_entropy_source(entropy_source);
 208                 let payment_id = Some(payment_id);
 209                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, payment_id);
 210                 let metadata = Metadata::DerivedSigningPubkey(derivation_material);
 211                 Self {
 212                         offer,
 213                         invoice_request: Self::create_contents(offer, metadata),
 214                         payer_id: None,
 215                         payer_id_strategy: core::marker::PhantomData,
 216                         secp_ctx: Some(secp_ctx),
 217                 }
 218         }
 219
 220         /// Builds a signed [`InvoiceRequest`] after checking for valid semantics.
 221         pub fn build_and_sign($self: $self_type) -> Result<InvoiceRequest, Bolt12SemanticError> {
 222                 let (unsigned_invoice_request, keys, secp_ctx) = $self.build_with_checks()?;
 223                 #[cfg(c_bindings)]
 224                 let mut unsigned_invoice_request = unsigned_invoice_request;
 225                 debug_assert!(keys.is_some());
 226
 227                 let secp_ctx = secp_ctx.unwrap();
 228                 let keys = keys.unwrap();
 229                 let invoice_request = unsigned_invoice_request
 230                         .sign(|message: &UnsignedInvoiceRequest|
 231                                 Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
 232                         )
 233                         .unwrap();
 234                 Ok(invoice_request)
 235         }
 236 } }
 237
 238 macro_rules! invoice_request_builder_methods { (
 239         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr, $secp_context: ty $(, $self_mut: tt)?
 240 ) => {
 241         #[cfg_attr(c_bindings, allow(dead_code))]
 242         fn create_contents(offer: &Offer, metadata: Metadata) -> InvoiceRequestContentsWithoutPayerId {
 243                 let offer = offer.contents.clone();
 244                 InvoiceRequestContentsWithoutPayerId {
 245                         payer: PayerContents(metadata), offer, chain: None, amount_msats: None,
 246                         features: InvoiceRequestFeatures::empty(), quantity: None, payer_note: None,
 247                 }
 248         }
 249
 250         /// Sets the [`InvoiceRequest::chain`] of the given [`Network`] for paying an invoice. If not
 251         /// called, [`Network::Bitcoin`] is assumed. Errors if the chain for `network` is not supported
 252         /// by the offer.
 253         ///
 254         /// Successive calls to this method will override the previous setting.
 255         pub fn chain($self: $self_type, network: Network) -> Result<$return_type, Bolt12SemanticError> {
 256                 $self.chain_hash(ChainHash::using_genesis_block(network))
 257         }
 258
 259         /// Sets the [`InvoiceRequest::chain`] for paying an invoice. If not called, the chain hash of
 260         /// [`Network::Bitcoin`] is assumed. Errors if the chain for `network` is not supported by the
 261         /// offer.
 262         ///
 263         /// Successive calls to this method will override the previous setting.
 264         pub(crate) fn chain_hash($($self_mut)* $self: $self_type, chain: ChainHash) -> Result<$return_type, Bolt12SemanticError> {
 265                 if !$self.offer.supports_chain(chain) {
 266                         return Err(Bolt12SemanticError::UnsupportedChain);
 267                 }
 268
 269                 $self.invoice_request.chain = Some(chain);
 270                 Ok($return_value)
 271         }
 272
 273         /// Sets the [`InvoiceRequest::amount_msats`] for paying an invoice. Errors if `amount_msats` is
 274         /// not at least the expected invoice amount (i.e., [`Offer::amount`] times [`quantity`]).
 275         ///
 276         /// Successive calls to this method will override the previous setting.
 277         ///
 278         /// [`quantity`]: Self::quantity
 279         pub fn amount_msats($($self_mut)* $self: $self_type, amount_msats: u64) -> Result<$return_type, Bolt12SemanticError> {
 280                 $self.invoice_request.offer.check_amount_msats_for_quantity(
 281                         Some(amount_msats), $self.invoice_request.quantity
 282                 )?;
 283                 $self.invoice_request.amount_msats = Some(amount_msats);
 284                 Ok($return_value)
 285         }
 286
 287         /// Sets [`InvoiceRequest::quantity`] of items. If not set, `1` is assumed. Errors if `quantity`
 288         /// does not conform to [`Offer::is_valid_quantity`].
 289         ///
 290         /// Successive calls to this method will override the previous setting.
 291         pub fn quantity($($self_mut)* $self: $self_type, quantity: u64) -> Result<$return_type, Bolt12SemanticError> {
 292                 $self.invoice_request.offer.check_quantity(Some(quantity))?;
 293                 $self.invoice_request.quantity = Some(quantity);
 294                 Ok($return_value)
 295         }
 296
 297         /// Sets the [`InvoiceRequest::payer_note`].
 298         ///
 299         /// Successive calls to this method will override the previous setting.
 300         pub fn payer_note($($self_mut)* $self: $self_type, payer_note: String) -> $return_type {
 301                 $self.invoice_request.payer_note = Some(payer_note);
 302                 $return_value
 303         }
 304
 305         fn build_with_checks($($self_mut)* $self: $self_type) -> Result<
 306                 (UnsignedInvoiceRequest, Option<KeyPair>, Option<&'b Secp256k1<$secp_context>>),
 307                 Bolt12SemanticError
 308         > {
 309                 #[cfg(feature = "std")] {
 310                         if $self.offer.is_expired() {
 311                                 return Err(Bolt12SemanticError::AlreadyExpired);
 312                         }
 313                 }
 314
 315                 let chain = $self.invoice_request.chain();
 316                 if !$self.offer.supports_chain(chain) {
 317                         return Err(Bolt12SemanticError::UnsupportedChain);
 318                 }
 319
 320                 if chain == $self.offer.implied_chain() {
 321                         $self.invoice_request.chain = None;
 322                 }
 323
 324                 if $self.offer.amount().is_none() && $self.invoice_request.amount_msats.is_none() {
 325                         return Err(Bolt12SemanticError::MissingAmount);
 326                 }
 327
 328                 $self.invoice_request.offer.check_quantity($self.invoice_request.quantity)?;
 329                 $self.invoice_request.offer.check_amount_msats_for_quantity(
 330                         $self.invoice_request.amount_msats, $self.invoice_request.quantity
 331                 )?;
 332
 333                 Ok($self.build_without_checks())
 334         }
 335
 336         fn build_without_checks($($self_mut)* $self: $self_type) ->
 337                 (UnsignedInvoiceRequest, Option<KeyPair>, Option<&'b Secp256k1<$secp_context>>)
 338         {
 339                 // Create the metadata for stateless verification of a Bolt12Invoice.
 340                 let mut keys = None;
 341                 let secp_ctx = $self.secp_ctx.clone();
 342                 if $self.invoice_request.payer.0.has_derivation_material() {
 343                         let mut metadata = core::mem::take(&mut $self.invoice_request.payer.0);
 344
 345                         let mut tlv_stream = $self.invoice_request.as_tlv_stream();
 346                         debug_assert!(tlv_stream.2.payer_id.is_none());
 347                         tlv_stream.0.metadata = None;
 348                         if !metadata.derives_payer_keys() {
 349                                 tlv_stream.2.payer_id = $self.payer_id.as_ref();
 350                         }
 351
 352                         let (derived_metadata, derived_keys) = metadata.derive_from(tlv_stream, $self.secp_ctx);
 353                         metadata = derived_metadata;
 354                         keys = derived_keys;
 355                         if let Some(keys) = keys {
 356                                 debug_assert!($self.payer_id.is_none());
 357                                 $self.payer_id = Some(keys.public_key());
 358                         }
 359
 360                         $self.invoice_request.payer.0 = metadata;
 361                 }
 362
 363                 debug_assert!($self.invoice_request.payer.0.as_bytes().is_some());
 364                 debug_assert!($self.payer_id.is_some());
 365                 let payer_id = $self.payer_id.unwrap();
 366
 367                 let invoice_request = InvoiceRequestContents {
 368                         #[cfg(not(c_bindings))]
 369                         inner: $self.invoice_request,
 370                         #[cfg(c_bindings)]
 371                         inner: $self.invoice_request.clone(),
 372                         payer_id,
 373                 };
 374                 let unsigned_invoice_request = UnsignedInvoiceRequest::new($self.offer, invoice_request);
 375
 376                 (unsigned_invoice_request, keys, secp_ctx)
 377         }
 378 } }
 379
 380 #[cfg(test)]
 381 macro_rules! invoice_request_builder_test_methods { (
 382         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
 383 ) => {
 384         #[cfg_attr(c_bindings, allow(dead_code))]
 385         fn chain_unchecked($($self_mut)* $self: $self_type, network: Network) -> $return_type {
 386                 let chain = ChainHash::using_genesis_block(network);
 387                 $self.invoice_request.chain = Some(chain);
 388                 $return_value
 389         }
 390
 391         #[cfg_attr(c_bindings, allow(dead_code))]
 392         fn amount_msats_unchecked($($self_mut)* $self: $self_type, amount_msats: u64) -> $return_type {
 393                 $self.invoice_request.amount_msats = Some(amount_msats);
 394                 $return_value
 395         }
 396
 397         #[cfg_attr(c_bindings, allow(dead_code))]
 398         fn features_unchecked($($self_mut)* $self: $self_type, features: InvoiceRequestFeatures) -> $return_type {
 399                 $self.invoice_request.features = features;
 400                 $return_value
 401         }
 402
 403         #[cfg_attr(c_bindings, allow(dead_code))]
 404         fn quantity_unchecked($($self_mut)* $self: $self_type, quantity: u64) -> $return_type {
 405                 $self.invoice_request.quantity = Some(quantity);
 406                 $return_value
 407         }
 408
 409         #[cfg_attr(c_bindings, allow(dead_code))]
 410         pub(super) fn build_unchecked($self: $self_type) -> UnsignedInvoiceRequest {
 411                 $self.build_without_checks().0
 412         }
 413 } }
 414
 415 impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, ExplicitPayerId, T> {
 416         invoice_request_explicit_payer_id_builder_methods!(self, Self);
 417 }
 418
 419 impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T> {
 420         invoice_request_derived_payer_id_builder_methods!(self, Self, T);
 421 }
 422
 423 impl<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, P, T> {
 424         invoice_request_builder_methods!(self, Self, Self, self, T, mut);
 425
 426         #[cfg(test)]
 427         invoice_request_builder_test_methods!(self, Self, Self, self, mut);
 428 }
 429
 430 #[cfg(all(c_bindings, not(test)))]
 431 impl<'a, 'b> InvoiceRequestWithExplicitPayerIdBuilder<'a, 'b> {
 432         invoice_request_explicit_payer_id_builder_methods!(self, &mut Self);
 433         invoice_request_builder_methods!(self, &mut Self, (), (), secp256k1::All);
 434 }
 435
 436 #[cfg(all(c_bindings, test))]
 437 impl<'a, 'b> InvoiceRequestWithExplicitPayerIdBuilder<'a, 'b> {
 438         invoice_request_explicit_payer_id_builder_methods!(self, &mut Self);
 439         invoice_request_builder_methods!(self, &mut Self, &mut Self, self, secp256k1::All);
 440         invoice_request_builder_test_methods!(self, &mut Self, &mut Self, self);
 441 }
 442
 443 #[cfg(all(c_bindings, not(test)))]
 444 impl<'a, 'b> InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b> {
 445         invoice_request_derived_payer_id_builder_methods!(self, &mut Self, secp256k1::All);
 446         invoice_request_builder_methods!(self, &mut Self, (), (), secp256k1::All);
 447 }
 448
 449 #[cfg(all(c_bindings, test))]
 450 impl<'a, 'b> InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b> {
 451         invoice_request_derived_payer_id_builder_methods!(self, &mut Self, secp256k1::All);
 452         invoice_request_builder_methods!(self, &mut Self, &mut Self, self, secp256k1::All);
 453         invoice_request_builder_test_methods!(self, &mut Self, &mut Self, self);
 454 }
 455
 456 #[cfg(c_bindings)]
 457 impl<'a, 'b> From<InvoiceRequestWithExplicitPayerIdBuilder<'a, 'b>>
 458 for InvoiceRequestBuilder<'a, 'b, ExplicitPayerId, secp256k1::All> {
 459         fn from(builder: InvoiceRequestWithExplicitPayerIdBuilder<'a, 'b>) -> Self {
 460                 let InvoiceRequestWithExplicitPayerIdBuilder {
 461                         offer, invoice_request, payer_id, payer_id_strategy, secp_ctx,
 462                 } = builder;
 463
 464                 Self {
 465                         offer, invoice_request, payer_id, payer_id_strategy, secp_ctx,
 466                 }
 467         }
 468 }
 469
 470 #[cfg(c_bindings)]
 471 impl<'a, 'b> From<InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b>>
 472 for InvoiceRequestBuilder<'a, 'b, DerivedPayerId, secp256k1::All> {
 473         fn from(builder: InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b>) -> Self {
 474                 let InvoiceRequestWithDerivedPayerIdBuilder {
 475                         offer, invoice_request, payer_id, payer_id_strategy, secp_ctx,
 476                 } = builder;
 477
 478                 Self {
 479                         offer, invoice_request, payer_id, payer_id_strategy, secp_ctx,
 480                 }
 481         }
 482 }
 483
 484 /// A semantically valid [`InvoiceRequest`] that hasn't been signed.
 485 ///
 486 /// # Serialization
 487 ///
 488 /// This is serialized as a TLV stream, which includes TLV records from the originating message. As
 489 /// such, it may include unknown, odd TLV records.
 490 pub struct UnsignedInvoiceRequest {
 491         bytes: Vec<u8>,
 492         contents: InvoiceRequestContents,
 493         tagged_hash: TaggedHash,
 494 }
 495
 496 /// A function for signing an [`UnsignedInvoiceRequest`].
 497 pub trait SignInvoiceRequestFn {
 498         /// Signs a [`TaggedHash`] computed over the merkle root of `message`'s TLV stream.
 499         fn sign_invoice_request(&self, message: &UnsignedInvoiceRequest) -> Result<Signature, ()>;
 500 }
 501
 502 impl<F> SignInvoiceRequestFn for F
 503 where
 504         F: Fn(&UnsignedInvoiceRequest) -> Result<Signature, ()>,
 505 {
 506         fn sign_invoice_request(&self, message: &UnsignedInvoiceRequest) -> Result<Signature, ()> {
 507                 self(message)
 508         }
 509 }
 510
 511 impl<F> SignFn<UnsignedInvoiceRequest> for F
 512 where
 513         F: SignInvoiceRequestFn,
 514 {
 515         fn sign(&self, message: &UnsignedInvoiceRequest) -> Result<Signature, ()> {
 516                 self.sign_invoice_request(message)
 517         }
 518 }
 519
 520 impl UnsignedInvoiceRequest {
 521         fn new(offer: &Offer, contents: InvoiceRequestContents) -> Self {
 522                 // Use the offer bytes instead of the offer TLV stream as the offer may have contained
 523                 // unknown TLV records, which are not stored in `OfferContents`.
 524                 let (payer_tlv_stream, _offer_tlv_stream, invoice_request_tlv_stream) =
 525                         contents.as_tlv_stream();
 526                 let offer_bytes = WithoutLength(&offer.bytes);
 527                 let unsigned_tlv_stream = (payer_tlv_stream, offer_bytes, invoice_request_tlv_stream);
 528
 529                 let mut bytes = Vec::new();
 530                 unsigned_tlv_stream.write(&mut bytes).unwrap();
 531
 532                 let tagged_hash = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &bytes);
 533
 534                 Self { bytes, contents, tagged_hash }
 535         }
 536
 537         /// Returns the [`TaggedHash`] of the invoice to sign.
 538         pub fn tagged_hash(&self) -> &TaggedHash {
 539                 &self.tagged_hash
 540         }
 541 }
 542
 543 macro_rules! unsigned_invoice_request_sign_method { (
 544         $self: ident, $self_type: ty $(, $self_mut: tt)?
 545 ) => {
 546         /// Signs the [`TaggedHash`] of the invoice request using the given function.
 547         ///
 548         /// Note: The hash computation may have included unknown, odd TLV records.
 549         pub fn sign<F: SignInvoiceRequestFn>(
 550                 $($self_mut)* $self: $self_type, sign: F
 551         ) -> Result<InvoiceRequest, SignError> {
 552                 let pubkey = $self.contents.payer_id;
 553                 let signature = merkle::sign_message(sign, &$self, pubkey)?;
 554
 555                 // Append the signature TLV record to the bytes.
 556                 let signature_tlv_stream = SignatureTlvStreamRef {
 557                         signature: Some(&signature),
 558                 };
 559                 signature_tlv_stream.write(&mut $self.bytes).unwrap();
 560
 561                 Ok(InvoiceRequest {
 562                         #[cfg(not(c_bindings))]
 563                         bytes: $self.bytes,
 564                         #[cfg(c_bindings)]
 565                         bytes: $self.bytes.clone(),
 566                         #[cfg(not(c_bindings))]
 567                         contents: $self.contents,
 568                         #[cfg(c_bindings)]
 569                         contents: $self.contents.clone(),
 570                         signature,
 571                 })
 572         }
 573 } }
 574
 575 #[cfg(not(c_bindings))]
 576 impl UnsignedInvoiceRequest {
 577         unsigned_invoice_request_sign_method!(self, Self, mut);
 578 }
 579
 580 #[cfg(c_bindings)]
 581 impl UnsignedInvoiceRequest {
 582         unsigned_invoice_request_sign_method!(self, &mut Self);
 583 }
 584
 585 impl AsRef<TaggedHash> for UnsignedInvoiceRequest {
 586         fn as_ref(&self) -> &TaggedHash {
 587                 &self.tagged_hash
 588         }
 589 }
 590
 591 /// An `InvoiceRequest` is a request for a [`Bolt12Invoice`] formulated from an [`Offer`].
 592 ///
 593 /// An offer may provide choices such as quantity, amount, chain, features, etc. An invoice request
 594 /// specifies these such that its recipient can send an invoice for payment.
 595 ///
 596 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 597 /// [`Offer`]: crate::offers::offer::Offer
 598 #[derive(Clone, Debug)]
 599 #[cfg_attr(test, derive(PartialEq))]
 600 pub struct InvoiceRequest {
 601         pub(super) bytes: Vec<u8>,
 602         pub(super) contents: InvoiceRequestContents,
 603         signature: Signature,
 604 }
 605
 606 /// An [`InvoiceRequest`] that has been verified by [`InvoiceRequest::verify`] and exposes different
 607 /// ways to respond depending on whether the signing keys were derived.
 608 #[derive(Clone, Debug)]
 609 pub struct VerifiedInvoiceRequest {
 610         /// The identifier of the [`Offer`] for which the [`InvoiceRequest`] was made.
 611         pub offer_id: OfferId,
 612
 613         /// The verified request.
 614         inner: InvoiceRequest,
 615
 616         /// Keys used for signing a [`Bolt12Invoice`] if they can be derived.
 617         ///
 618         /// If `Some`, must call [`respond_using_derived_keys`] when responding. Otherwise, call
 619         /// [`respond_with`].
 620         ///
 621         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 622         /// [`respond_using_derived_keys`]: Self::respond_using_derived_keys
 623         /// [`respond_with`]: Self::respond_with
 624         pub keys: Option<KeyPair>,
 625 }
 626
 627 /// The contents of an [`InvoiceRequest`], which may be shared with an [`Bolt12Invoice`].
 628 ///
 629 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 630 #[derive(Clone, Debug)]
 631 #[cfg_attr(test, derive(PartialEq))]
 632 pub(super) struct InvoiceRequestContents {
 633         pub(super) inner: InvoiceRequestContentsWithoutPayerId,
 634         payer_id: PublicKey,
 635 }
 636
 637 #[derive(Clone, Debug)]
 638 #[cfg_attr(test, derive(PartialEq))]
 639 pub(super) struct InvoiceRequestContentsWithoutPayerId {
 640         payer: PayerContents,
 641         pub(super) offer: OfferContents,
 642         chain: Option<ChainHash>,
 643         amount_msats: Option<u64>,
 644         features: InvoiceRequestFeatures,
 645         quantity: Option<u64>,
 646         payer_note: Option<String>,
 647 }
 648
 649 macro_rules! invoice_request_accessors { ($self: ident, $contents: expr) => {
 650         /// An unpredictable series of bytes, typically containing information about the derivation of
 651         /// [`payer_id`].
 652         ///
 653         /// [`payer_id`]: Self::payer_id
 654         pub fn payer_metadata(&$self) -> &[u8] {
 655                 $contents.metadata()
 656         }
 657
 658         /// A chain from [`Offer::chains`] that the offer is valid for.
 659         pub fn chain(&$self) -> ChainHash {
 660                 $contents.chain()
 661         }
 662
 663         /// The amount to pay in msats (i.e., the minimum lightning-payable unit for [`chain`]), which
 664         /// must be greater than or equal to [`Offer::amount`], converted if necessary.
 665         ///
 666         /// [`chain`]: Self::chain
 667         pub fn amount_msats(&$self) -> Option<u64> {
 668                 $contents.amount_msats()
 669         }
 670
 671         /// Features pertaining to requesting an invoice.
 672         pub fn invoice_request_features(&$self) -> &InvoiceRequestFeatures {
 673                 &$contents.features()
 674         }
 675
 676         /// The quantity of the offer's item conforming to [`Offer::is_valid_quantity`].
 677         pub fn quantity(&$self) -> Option<u64> {
 678                 $contents.quantity()
 679         }
 680
 681         /// A possibly transient pubkey used to sign the invoice request.
 682         pub fn payer_id(&$self) -> PublicKey {
 683                 $contents.payer_id()
 684         }
 685
 686         /// A payer-provided note which will be seen by the recipient and reflected back in the invoice
 687         /// response.
 688         pub fn payer_note(&$self) -> Option<PrintableString> {
 689                 $contents.payer_note()
 690         }
 691 } }
 692
 693 impl UnsignedInvoiceRequest {
 694         offer_accessors!(self, self.contents.inner.offer);
 695         invoice_request_accessors!(self, self.contents);
 696 }
 697
 698 macro_rules! invoice_request_respond_with_explicit_signing_pubkey_methods { (
 699         $self: ident, $contents: expr, $builder: ty
 700 ) => {
 701         /// Creates an [`InvoiceBuilder`] for the request with the given required fields and using the
 702         /// [`Duration`] since [`std::time::SystemTime::UNIX_EPOCH`] as the creation time.
 703         ///
 704         /// See [`InvoiceRequest::respond_with_no_std`] for further details where the aforementioned
 705         /// creation time is used for the `created_at` parameter.
 706         ///
 707         /// [`Duration`]: core::time::Duration
 708         #[cfg(feature = "std")]
 709         pub fn respond_with(
 710                 &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash
 711         ) -> Result<$builder, Bolt12SemanticError> {
 712                 let created_at = std::time::SystemTime::now()
 713                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 714                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 715
 716                 $contents.respond_with_no_std(payment_paths, payment_hash, created_at)
 717         }
 718
 719         /// Creates an [`InvoiceBuilder`] for the request with the given required fields.
 720         ///
 721         /// Unless [`InvoiceBuilder::relative_expiry`] is set, the invoice will expire two hours after
 722         /// `created_at`, which is used to set [`Bolt12Invoice::created_at`]. Useful for `no-std` builds
 723         /// where [`std::time::SystemTime`] is not available.
 724         ///
 725         /// The caller is expected to remember the preimage of `payment_hash` in order to claim a payment
 726         /// for the invoice.
 727         ///
 728         /// The `payment_paths` parameter is useful for maintaining the payment recipient's privacy. It
 729         /// must contain one or more elements ordered from most-preferred to least-preferred, if there's
 730         /// a preference. Note, however, that any privacy is lost if a public node id was used for
 731         /// [`Offer::signing_pubkey`].
 732         ///
 733         /// Errors if the request contains unknown required features.
 734         ///
 735         /// # Note
 736         ///
 737         /// If the originating [`Offer`] was created using [`OfferBuilder::deriving_signing_pubkey`],
 738         /// then use [`InvoiceRequest::verify`] and [`VerifiedInvoiceRequest`] methods instead.
 739         ///
 740         /// [`Bolt12Invoice::created_at`]: crate::offers::invoice::Bolt12Invoice::created_at
 741         /// [`OfferBuilder::deriving_signing_pubkey`]: crate::offers::offer::OfferBuilder::deriving_signing_pubkey
 742         pub fn respond_with_no_std(
 743                 &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 744                 created_at: core::time::Duration
 745         ) -> Result<$builder, Bolt12SemanticError> {
 746                 if $contents.invoice_request_features().requires_unknown_bits() {
 747                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 748                 }
 749
 750                 let signing_pubkey = match $contents.contents.inner.offer.signing_pubkey() {
 751                         Some(signing_pubkey) => signing_pubkey,
 752                         None => return Err(Bolt12SemanticError::MissingSigningPubkey),
 753                 };
 754
 755                 <$builder>::for_offer(&$contents, payment_paths, created_at, payment_hash, signing_pubkey)
 756         }
 757
 758         #[cfg(test)]
 759         #[allow(dead_code)]
 760         pub(super) fn respond_with_no_std_using_signing_pubkey(
 761                 &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 762                 created_at: core::time::Duration, signing_pubkey: PublicKey
 763         ) -> Result<$builder, Bolt12SemanticError> {
 764                 debug_assert!($contents.contents.inner.offer.signing_pubkey().is_none());
 765
 766                 if $contents.invoice_request_features().requires_unknown_bits() {
 767                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 768                 }
 769
 770                 <$builder>::for_offer(&$contents, payment_paths, created_at, payment_hash, signing_pubkey)
 771         }
 772 } }
 773
 774 macro_rules! invoice_request_verify_method { ($self: ident, $self_type: ty) => {
 775         /// Verifies that the request was for an offer created using the given key. Returns the verified
 776         /// request which contains the derived keys needed to sign a [`Bolt12Invoice`] for the request
 777         /// if they could be extracted from the metadata.
 778         ///
 779         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 780         pub fn verify<
 781                 #[cfg(not(c_bindings))]
 782                 T: secp256k1::Signing
 783         >(
 784                 $self: $self_type, key: &ExpandedKey,
 785                 #[cfg(not(c_bindings))]
 786                 secp_ctx: &Secp256k1<T>,
 787                 #[cfg(c_bindings)]
 788                 secp_ctx: &Secp256k1<secp256k1::All>,
 789         ) -> Result<VerifiedInvoiceRequest, ()> {
 790                 let (offer_id, keys) = $self.contents.inner.offer.verify(&$self.bytes, key, secp_ctx)?;
 791                 Ok(VerifiedInvoiceRequest {
 792                         offer_id,
 793                         #[cfg(not(c_bindings))]
 794                         inner: $self,
 795                         #[cfg(c_bindings)]
 796                         inner: $self.clone(),
 797                         keys,
 798                 })
 799         }
 800
 801 } }
 802
 803 #[cfg(not(c_bindings))]
 804 impl InvoiceRequest {
 805         offer_accessors!(self, self.contents.inner.offer);
 806         invoice_request_accessors!(self, self.contents);
 807         invoice_request_respond_with_explicit_signing_pubkey_methods!(self, self, InvoiceBuilder<ExplicitSigningPubkey>);
 808         invoice_request_verify_method!(self, Self);
 809 }
 810
 811 #[cfg(c_bindings)]
 812 impl InvoiceRequest {
 813         offer_accessors!(self, self.contents.inner.offer);
 814         invoice_request_accessors!(self, self.contents);
 815         invoice_request_respond_with_explicit_signing_pubkey_methods!(self, self, InvoiceWithExplicitSigningPubkeyBuilder);
 816         invoice_request_verify_method!(self, &Self);
 817 }
 818
 819 impl InvoiceRequest {
 820         /// Signature of the invoice request using [`payer_id`].
 821         ///
 822         /// [`payer_id`]: Self::payer_id
 823         pub fn signature(&self) -> Signature {
 824                 self.signature
 825         }
 826
 827         pub(crate) fn as_tlv_stream(&self) -> FullInvoiceRequestTlvStreamRef {
 828                 let (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream) =
 829                         self.contents.as_tlv_stream();
 830                 let signature_tlv_stream = SignatureTlvStreamRef {
 831                         signature: Some(&self.signature),
 832                 };
 833                 (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, signature_tlv_stream)
 834         }
 835 }
 836
 837 macro_rules! invoice_request_respond_with_derived_signing_pubkey_methods { (
 838         $self: ident, $contents: expr, $builder: ty
 839 ) => {
 840         /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
 841         /// derived signing keys from the originating [`Offer`] to sign the [`Bolt12Invoice`]. Must use
 842         /// the same [`ExpandedKey`] as the one used to create the offer.
 843         ///
 844         /// See [`InvoiceRequest::respond_with`] for further details.
 845         ///
 846         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 847         #[cfg(feature = "std")]
 848         pub fn respond_using_derived_keys(
 849                 &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash
 850         ) -> Result<$builder, Bolt12SemanticError> {
 851                 let created_at = std::time::SystemTime::now()
 852                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 853                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 854
 855                 $self.respond_using_derived_keys_no_std(payment_paths, payment_hash, created_at)
 856         }
 857
 858         /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
 859         /// derived signing keys from the originating [`Offer`] to sign the [`Bolt12Invoice`]. Must use
 860         /// the same [`ExpandedKey`] as the one used to create the offer.
 861         ///
 862         /// See [`InvoiceRequest::respond_with_no_std`] for further details.
 863         ///
 864         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 865         pub fn respond_using_derived_keys_no_std(
 866                 &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 867                 created_at: core::time::Duration
 868         ) -> Result<$builder, Bolt12SemanticError> {
 869                 if $self.inner.invoice_request_features().requires_unknown_bits() {
 870                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 871                 }
 872
 873                 let keys = match $self.keys {
 874                         None => return Err(Bolt12SemanticError::InvalidMetadata),
 875                         Some(keys) => keys,
 876                 };
 877
 878                 match $contents.contents.inner.offer.signing_pubkey() {
 879                         Some(signing_pubkey) => debug_assert_eq!(signing_pubkey, keys.public_key()),
 880                         None => return Err(Bolt12SemanticError::MissingSigningPubkey),
 881                 }
 882
 883                 <$builder>::for_offer_using_keys(
 884                         &$self.inner, payment_paths, created_at, payment_hash, keys
 885                 )
 886         }
 887 } }
 888
 889 impl VerifiedInvoiceRequest {
 890         offer_accessors!(self, self.inner.contents.inner.offer);
 891         invoice_request_accessors!(self, self.inner.contents);
 892         #[cfg(not(c_bindings))]
 893         invoice_request_respond_with_explicit_signing_pubkey_methods!(self, self.inner, InvoiceBuilder<ExplicitSigningPubkey>);
 894         #[cfg(c_bindings)]
 895         invoice_request_respond_with_explicit_signing_pubkey_methods!(self, self.inner, InvoiceWithExplicitSigningPubkeyBuilder);
 896         #[cfg(not(c_bindings))]
 897         invoice_request_respond_with_derived_signing_pubkey_methods!(self, self.inner, InvoiceBuilder<DerivedSigningPubkey>);
 898         #[cfg(c_bindings)]
 899         invoice_request_respond_with_derived_signing_pubkey_methods!(self, self.inner, InvoiceWithDerivedSigningPubkeyBuilder);
 900
 901         pub(crate) fn fields(&self) -> InvoiceRequestFields {
 902                 let InvoiceRequestContents {
 903                         payer_id,
 904                         inner: InvoiceRequestContentsWithoutPayerId {
 905                                 payer: _, offer: _, chain: _, amount_msats: _, features: _, quantity, payer_note
 906                         },
 907                 } = &self.inner.contents;
 908
 909                 InvoiceRequestFields {
 910                         payer_id: *payer_id,
 911                         quantity: *quantity,
 912                         payer_note_truncated: payer_note.clone()
 913                                 .map(|mut s| { s.truncate(PAYER_NOTE_LIMIT); UntrustedString(s) }),
 914                 }
 915         }
 916 }
 917
 918 impl InvoiceRequestContents {
 919         pub(super) fn metadata(&self) -> &[u8] {
 920                 self.inner.metadata()
 921         }
 922
 923         pub(super) fn derives_keys(&self) -> bool {
 924                 self.inner.payer.0.derives_payer_keys()
 925         }
 926
 927         pub(super) fn chain(&self) -> ChainHash {
 928                 self.inner.chain()
 929         }
 930
 931         pub(super) fn amount_msats(&self) -> Option<u64> {
 932                 self.inner.amount_msats
 933         }
 934
 935         pub(super) fn features(&self) -> &InvoiceRequestFeatures {
 936                 &self.inner.features
 937         }
 938
 939         pub(super) fn quantity(&self) -> Option<u64> {
 940                 self.inner.quantity
 941         }
 942
 943         pub(super) fn payer_id(&self) -> PublicKey {
 944                 self.payer_id
 945         }
 946
 947         pub(super) fn payer_note(&self) -> Option<PrintableString> {
 948                 self.inner.payer_note.as_ref()
 949                         .map(|payer_note| PrintableString(payer_note.as_str()))
 950         }
 951
 952         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 953                 let (payer, offer, mut invoice_request) = self.inner.as_tlv_stream();
 954                 invoice_request.payer_id = Some(&self.payer_id);
 955                 (payer, offer, invoice_request)
 956         }
 957 }
 958
 959 impl InvoiceRequestContentsWithoutPayerId {
 960         pub(super) fn metadata(&self) -> &[u8] {
 961                 self.payer.0.as_bytes().map(|bytes| bytes.as_slice()).unwrap_or(&[])
 962         }
 963
 964         pub(super) fn chain(&self) -> ChainHash {
 965                 self.chain.unwrap_or_else(|| self.offer.implied_chain())
 966         }
 967
 968         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 969                 let payer = PayerTlvStreamRef {
 970                         metadata: self.payer.0.as_bytes(),
 971                 };
 972
 973                 let offer = self.offer.as_tlv_stream();
 974
 975                 let features = {
 976                         if self.features == InvoiceRequestFeatures::empty() { None }
 977                         else { Some(&self.features) }
 978                 };
 979
 980                 let invoice_request = InvoiceRequestTlvStreamRef {
 981                         chain: self.chain.as_ref(),
 982                         amount: self.amount_msats,
 983                         features,
 984                         quantity: self.quantity,
 985                         payer_id: None,
 986                         payer_note: self.payer_note.as_ref(),
 987                         paths: None,
 988                 };
 989
 990                 (payer, offer, invoice_request)
 991         }
 992 }
 993
 994 impl Writeable for UnsignedInvoiceRequest {
 995         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 996                 WithoutLength(&self.bytes).write(writer)
 997         }
 998 }
 999
1000 impl Writeable for InvoiceRequest {
1001         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
1002                 WithoutLength(&self.bytes).write(writer)
1003         }
1004 }
1005
1006 impl Writeable for InvoiceRequestContents {
1007         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
1008                 self.as_tlv_stream().write(writer)
1009         }
1010 }
1011
1012 /// Valid type range for invoice_request TLV records.
1013 pub(super) const INVOICE_REQUEST_TYPES: core::ops::Range<u64> = 80..160;
1014
1015 /// TLV record type for [`InvoiceRequest::payer_id`] and [`Refund::payer_id`].
1016 ///
1017 /// [`Refund::payer_id`]: crate::offers::refund::Refund::payer_id
1018 pub(super) const INVOICE_REQUEST_PAYER_ID_TYPE: u64 = 88;
1019
1020 // This TLV stream is used for both InvoiceRequest and Refund, but not all TLV records are valid for
1021 // InvoiceRequest as noted below.
1022 tlv_stream!(InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef, INVOICE_REQUEST_TYPES, {
1023         (80, chain: ChainHash),
1024         (82, amount: (u64, HighZeroBytesDroppedBigSize)),
1025         (84, features: (InvoiceRequestFeatures, WithoutLength)),
1026         (86, quantity: (u64, HighZeroBytesDroppedBigSize)),
1027         (INVOICE_REQUEST_PAYER_ID_TYPE, payer_id: PublicKey),
1028         (89, payer_note: (String, WithoutLength)),
1029         // Only used for Refund since the onion message of an InvoiceRequest has a reply path.
1030         (90, paths: (Vec<BlindedPath>, WithoutLength)),
1031 });
1032
1033 type FullInvoiceRequestTlvStream =
1034         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, SignatureTlvStream);
1035
1036 type FullInvoiceRequestTlvStreamRef<'a> = (
1037         PayerTlvStreamRef<'a>,
1038         OfferTlvStreamRef<'a>,
1039         InvoiceRequestTlvStreamRef<'a>,
1040         SignatureTlvStreamRef<'a>,
1041 );
1042
1043 impl SeekReadable for FullInvoiceRequestTlvStream {
1044         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
1045                 let payer = SeekReadable::read(r)?;
1046                 let offer = SeekReadable::read(r)?;
1047                 let invoice_request = SeekReadable::read(r)?;
1048                 let signature = SeekReadable::read(r)?;
1049
1050                 Ok((payer, offer, invoice_request, signature))
1051         }
1052 }
1053
1054 type PartialInvoiceRequestTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
1055
1056 type PartialInvoiceRequestTlvStreamRef<'a> = (
1057         PayerTlvStreamRef<'a>,
1058         OfferTlvStreamRef<'a>,
1059         InvoiceRequestTlvStreamRef<'a>,
1060 );
1061
1062 impl TryFrom<Vec<u8>> for UnsignedInvoiceRequest {
1063         type Error = Bolt12ParseError;
1064
1065         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
1066                 let invoice_request = ParsedMessage::<PartialInvoiceRequestTlvStream>::try_from(bytes)?;
1067                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
1068                 let (
1069                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
1070                 ) = tlv_stream;
1071                 let contents = InvoiceRequestContents::try_from(
1072                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
1073                 )?;
1074
1075                 let tagged_hash = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &bytes);
1076
1077                 Ok(UnsignedInvoiceRequest { bytes, contents, tagged_hash })
1078         }
1079 }
1080
1081 impl TryFrom<Vec<u8>> for InvoiceRequest {
1082         type Error = Bolt12ParseError;
1083
1084         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
1085                 let invoice_request = ParsedMessage::<FullInvoiceRequestTlvStream>::try_from(bytes)?;
1086                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
1087                 let (
1088                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
1089                         SignatureTlvStream { signature },
1090                 ) = tlv_stream;
1091                 let contents = InvoiceRequestContents::try_from(
1092                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
1093                 )?;
1094
1095                 let signature = match signature {
1096                         None => return Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
1097                         Some(signature) => signature,
1098                 };
1099                 let message = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &bytes);
1100                 merkle::verify_signature(&signature, &message, contents.payer_id)?;
1101
1102                 Ok(InvoiceRequest { bytes, contents, signature })
1103         }
1104 }
1105
1106 impl TryFrom<PartialInvoiceRequestTlvStream> for InvoiceRequestContents {
1107         type Error = Bolt12SemanticError;
1108
1109         fn try_from(tlv_stream: PartialInvoiceRequestTlvStream) -> Result<Self, Self::Error> {
1110                 let (
1111                         PayerTlvStream { metadata },
1112                         offer_tlv_stream,
1113                         InvoiceRequestTlvStream {
1114                                 chain, amount, features, quantity, payer_id, payer_note, paths,
1115                         },
1116                 ) = tlv_stream;
1117
1118                 let payer = match metadata {
1119                         None => return Err(Bolt12SemanticError::MissingPayerMetadata),
1120                         Some(metadata) => PayerContents(Metadata::Bytes(metadata)),
1121                 };
1122                 let offer = OfferContents::try_from(offer_tlv_stream)?;
1123
1124                 if !offer.supports_chain(chain.unwrap_or_else(|| offer.implied_chain())) {
1125                         return Err(Bolt12SemanticError::UnsupportedChain);
1126                 }
1127
1128                 if offer.amount().is_none() && amount.is_none() {
1129                         return Err(Bolt12SemanticError::MissingAmount);
1130                 }
1131
1132                 offer.check_quantity(quantity)?;
1133                 offer.check_amount_msats_for_quantity(amount, quantity)?;
1134
1135                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
1136
1137                 let payer_id = match payer_id {
1138                         None => return Err(Bolt12SemanticError::MissingPayerId),
1139                         Some(payer_id) => payer_id,
1140                 };
1141
1142                 if paths.is_some() {
1143                         return Err(Bolt12SemanticError::UnexpectedPaths);
1144                 }
1145
1146                 Ok(InvoiceRequestContents {
1147                         inner: InvoiceRequestContentsWithoutPayerId {
1148                                 payer, offer, chain, amount_msats: amount, features, quantity, payer_note,
1149                         },
1150                         payer_id,
1151                 })
1152         }
1153 }
1154
1155 /// Fields sent in an [`InvoiceRequest`] message to include in [`PaymentContext::Bolt12Offer`].
1156 ///
1157 /// [`PaymentContext::Bolt12Offer`]: crate::blinded_path::payment::PaymentContext::Bolt12Offer
1158 #[derive(Clone, Debug, Eq, PartialEq)]
1159 pub struct InvoiceRequestFields {
1160         /// A possibly transient pubkey used to sign the invoice request.
1161         pub payer_id: PublicKey,
1162
1163         /// The quantity of the offer's item conforming to [`Offer::is_valid_quantity`].
1164         pub quantity: Option<u64>,
1165
1166         /// A payer-provided note which will be seen by the recipient and reflected back in the invoice
1167         /// response. Truncated to [`PAYER_NOTE_LIMIT`] characters.
1168         pub payer_note_truncated: Option<UntrustedString>,
1169 }
1170
1171 /// The maximum number of characters included in [`InvoiceRequestFields::payer_note_truncated`].
1172 pub const PAYER_NOTE_LIMIT: usize = 512;
1173
1174 impl Writeable for InvoiceRequestFields {
1175         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
1176                 write_tlv_fields!(writer, {
1177                         (0, self.payer_id, required),
1178                         (2, self.quantity.map(|v| HighZeroBytesDroppedBigSize(v)), option),
1179                         (4, self.payer_note_truncated.as_ref().map(|s| WithoutLength(&s.0)), option),
1180                 });
1181                 Ok(())
1182         }
1183 }
1184
1185 impl Readable for InvoiceRequestFields {
1186         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
1187                 _init_and_read_len_prefixed_tlv_fields!(reader, {
1188                         (0, payer_id, required),
1189                         (2, quantity, (option, encoding: (u64, HighZeroBytesDroppedBigSize))),
1190                         (4, payer_note_truncated, (option, encoding: (String, WithoutLength))),
1191                 });
1192
1193                 Ok(InvoiceRequestFields {
1194                         payer_id: payer_id.0.unwrap(),
1195                         quantity,
1196                         payer_note_truncated: payer_note_truncated.map(|s| UntrustedString(s)),
1197                 })
1198         }
1199 }
1200
1201 #[cfg(test)]
1202 mod tests {
1203         use super::{InvoiceRequest, InvoiceRequestFields, InvoiceRequestTlvStreamRef, PAYER_NOTE_LIMIT, SIGNATURE_TAG, UnsignedInvoiceRequest};
1204
1205         use bitcoin::blockdata::constants::ChainHash;
1206         use bitcoin::network::constants::Network;
1207         use bitcoin::secp256k1::{KeyPair, Secp256k1, SecretKey, self};
1208         use core::num::NonZeroU64;
1209         #[cfg(feature = "std")]
1210         use core::time::Duration;
1211         use crate::sign::KeyMaterial;
1212         use crate::ln::channelmanager::PaymentId;
1213         use crate::ln::features::{InvoiceRequestFeatures, OfferFeatures};
1214         use crate::ln::inbound_payment::ExpandedKey;
1215         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
1216         use crate::offers::invoice::{Bolt12Invoice, SIGNATURE_TAG as INVOICE_SIGNATURE_TAG};
1217         use crate::offers::merkle::{SignError, SignatureTlvStreamRef, TaggedHash, self};
1218         use crate::offers::offer::{Amount, OfferTlvStreamRef, Quantity};
1219         #[cfg(not(c_bindings))]
1220         use {
1221                 crate::offers::offer::OfferBuilder,
1222         };
1223         #[cfg(c_bindings)]
1224         use {
1225                 crate::offers::offer::OfferWithExplicitMetadataBuilder as OfferBuilder,
1226         };
1227         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
1228         use crate::offers::payer::PayerTlvStreamRef;
1229         use crate::offers::test_utils::*;
1230         use crate::util::ser::{BigSize, Readable, Writeable};
1231         use crate::util::string::{PrintableString, UntrustedString};
1232
1233         #[test]
1234         fn builds_invoice_request_with_defaults() {
1235                 let unsigned_invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1236                         .amount_msats(1000)
1237                         .build().unwrap()
1238                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1239                         .build().unwrap();
1240                 #[cfg(c_bindings)]
1241                 let mut unsigned_invoice_request = unsigned_invoice_request;
1242
1243                 let mut buffer = Vec::new();
1244                 unsigned_invoice_request.write(&mut buffer).unwrap();
1245
1246                 assert_eq!(unsigned_invoice_request.bytes, buffer.as_slice());
1247                 assert_eq!(unsigned_invoice_request.payer_metadata(), &[1; 32]);
1248                 assert_eq!(unsigned_invoice_request.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
1249                 assert_eq!(unsigned_invoice_request.metadata(), None);
1250                 assert_eq!(unsigned_invoice_request.amount(), Some(&Amount::Bitcoin { amount_msats: 1000 }));
1251                 assert_eq!(unsigned_invoice_request.description(), PrintableString("foo"));
1252                 assert_eq!(unsigned_invoice_request.offer_features(), &OfferFeatures::empty());
1253                 assert_eq!(unsigned_invoice_request.absolute_expiry(), None);
1254                 assert_eq!(unsigned_invoice_request.paths(), &[]);
1255                 assert_eq!(unsigned_invoice_request.issuer(), None);
1256                 assert_eq!(unsigned_invoice_request.supported_quantity(), Quantity::One);
1257                 assert_eq!(unsigned_invoice_request.signing_pubkey(), Some(recipient_pubkey()));
1258                 assert_eq!(unsigned_invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
1259                 assert_eq!(unsigned_invoice_request.amount_msats(), None);
1260                 assert_eq!(unsigned_invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
1261                 assert_eq!(unsigned_invoice_request.quantity(), None);
1262                 assert_eq!(unsigned_invoice_request.payer_id(), payer_pubkey());
1263                 assert_eq!(unsigned_invoice_request.payer_note(), None);
1264
1265                 match UnsignedInvoiceRequest::try_from(buffer) {
1266                         Err(e) => panic!("error parsing unsigned invoice request: {:?}", e),
1267                         Ok(parsed) => {
1268                                 assert_eq!(parsed.bytes, unsigned_invoice_request.bytes);
1269                                 assert_eq!(parsed.tagged_hash, unsigned_invoice_request.tagged_hash);
1270                         },
1271                 }
1272
1273                 let invoice_request = unsigned_invoice_request.sign(payer_sign).unwrap();
1274
1275                 let mut buffer = Vec::new();
1276                 invoice_request.write(&mut buffer).unwrap();
1277
1278                 assert_eq!(invoice_request.bytes, buffer.as_slice());
1279                 assert_eq!(invoice_request.payer_metadata(), &[1; 32]);
1280                 assert_eq!(invoice_request.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
1281                 assert_eq!(invoice_request.metadata(), None);
1282                 assert_eq!(invoice_request.amount(), Some(&Amount::Bitcoin { amount_msats: 1000 }));
1283                 assert_eq!(invoice_request.description(), PrintableString("foo"));
1284                 assert_eq!(invoice_request.offer_features(), &OfferFeatures::empty());
1285                 assert_eq!(invoice_request.absolute_expiry(), None);
1286                 assert_eq!(invoice_request.paths(), &[]);
1287                 assert_eq!(invoice_request.issuer(), None);
1288                 assert_eq!(invoice_request.supported_quantity(), Quantity::One);
1289                 assert_eq!(invoice_request.signing_pubkey(), Some(recipient_pubkey()));
1290                 assert_eq!(invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
1291                 assert_eq!(invoice_request.amount_msats(), None);
1292                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
1293                 assert_eq!(invoice_request.quantity(), None);
1294                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
1295                 assert_eq!(invoice_request.payer_note(), None);
1296
1297                 let message = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &invoice_request.bytes);
1298                 assert!(merkle::verify_signature(&invoice_request.signature, &message, payer_pubkey()).is_ok());
1299
1300                 assert_eq!(
1301                         invoice_request.as_tlv_stream(),
1302                         (
1303                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
1304                                 OfferTlvStreamRef {
1305                                         chains: None,
1306                                         metadata: None,
1307                                         currency: None,
1308                                         amount: Some(1000),
1309                                         description: Some(&String::from("foo")),
1310                                         features: None,
1311                                         absolute_expiry: None,
1312                                         paths: None,
1313                                         issuer: None,
1314                                         quantity_max: None,
1315                                         node_id: Some(&recipient_pubkey()),
1316                                 },
1317                                 InvoiceRequestTlvStreamRef {
1318                                         chain: None,
1319                                         amount: None,
1320                                         features: None,
1321                                         quantity: None,
1322                                         payer_id: Some(&payer_pubkey()),
1323                                         payer_note: None,
1324                                         paths: None,
1325                                 },
1326                                 SignatureTlvStreamRef { signature: Some(&invoice_request.signature()) },
1327                         ),
1328                 );
1329
1330                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1331                         panic!("error parsing invoice request: {:?}", e);
1332                 }
1333         }
1334
1335         #[cfg(feature = "std")]
1336         #[test]
1337         fn builds_invoice_request_from_offer_with_expiration() {
1338                 let future_expiry = Duration::from_secs(u64::max_value());
1339                 let past_expiry = Duration::from_secs(0);
1340
1341                 if let Err(e) = OfferBuilder::new("foo".into(), recipient_pubkey())
1342                         .amount_msats(1000)
1343                         .absolute_expiry(future_expiry)
1344                         .build().unwrap()
1345                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1346                         .build()
1347                 {
1348                         panic!("error building invoice_request: {:?}", e);
1349                 }
1350
1351                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1352                         .amount_msats(1000)
1353                         .absolute_expiry(past_expiry)
1354                         .build().unwrap()
1355                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1356                         .build()
1357                 {
1358                         Ok(_) => panic!("expected error"),
1359                         Err(e) => assert_eq!(e, Bolt12SemanticError::AlreadyExpired),
1360                 }
1361         }
1362
1363         #[test]
1364         fn builds_invoice_request_with_derived_metadata() {
1365                 let payer_id = payer_pubkey();
1366                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1367                 let entropy = FixedEntropy {};
1368                 let secp_ctx = Secp256k1::new();
1369                 let payment_id = PaymentId([1; 32]);
1370
1371                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1372                         .amount_msats(1000)
1373                         .build().unwrap();
1374                 let invoice_request = offer
1375                         .request_invoice_deriving_metadata(payer_id, &expanded_key, &entropy, payment_id)
1376                         .unwrap()
1377                         .build().unwrap()
1378                         .sign(payer_sign).unwrap();
1379                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
1380
1381                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
1382                         .unwrap()
1383                         .build().unwrap()
1384                         .sign(recipient_sign).unwrap();
1385                 match invoice.verify(&expanded_key, &secp_ctx) {
1386                         Ok(payment_id) => assert_eq!(payment_id, PaymentId([1; 32])),
1387                         Err(()) => panic!("verification failed"),
1388                 }
1389
1390                 // Fails verification with altered fields
1391                 let (
1392                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
1393                         mut invoice_tlv_stream, mut signature_tlv_stream
1394                 ) = invoice.as_tlv_stream();
1395                 invoice_request_tlv_stream.amount = Some(2000);
1396                 invoice_tlv_stream.amount = Some(2000);
1397
1398                 let tlv_stream =
1399                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1400                 let mut bytes = Vec::new();
1401                 tlv_stream.write(&mut bytes).unwrap();
1402
1403                 let message = TaggedHash::from_valid_tlv_stream_bytes(INVOICE_SIGNATURE_TAG, &bytes);
1404                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1405                 signature_tlv_stream.signature = Some(&signature);
1406
1407                 let mut encoded_invoice = bytes;
1408                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1409
1410                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1411                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1412
1413                 // Fails verification with altered metadata
1414                 let (
1415                         mut payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
1416                         mut signature_tlv_stream
1417                 ) = invoice.as_tlv_stream();
1418                 let metadata = payer_tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1419                 payer_tlv_stream.metadata = Some(&metadata);
1420
1421                 let tlv_stream =
1422                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1423                 let mut bytes = Vec::new();
1424                 tlv_stream.write(&mut bytes).unwrap();
1425
1426                 let message = TaggedHash::from_valid_tlv_stream_bytes(INVOICE_SIGNATURE_TAG, &bytes);
1427                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1428                 signature_tlv_stream.signature = Some(&signature);
1429
1430                 let mut encoded_invoice = bytes;
1431                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1432
1433                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1434                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1435         }
1436
1437         #[test]
1438         fn builds_invoice_request_with_derived_payer_id() {
1439                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1440                 let entropy = FixedEntropy {};
1441                 let secp_ctx = Secp256k1::new();
1442                 let payment_id = PaymentId([1; 32]);
1443
1444                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1445                         .amount_msats(1000)
1446                         .build().unwrap();
1447                 let invoice_request = offer
1448                         .request_invoice_deriving_payer_id(&expanded_key, &entropy, &secp_ctx, payment_id)
1449                         .unwrap()
1450                         .build_and_sign()
1451                         .unwrap();
1452
1453                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
1454                         .unwrap()
1455                         .build().unwrap()
1456                         .sign(recipient_sign).unwrap();
1457                 match invoice.verify(&expanded_key, &secp_ctx) {
1458                         Ok(payment_id) => assert_eq!(payment_id, PaymentId([1; 32])),
1459                         Err(()) => panic!("verification failed"),
1460                 }
1461
1462                 // Fails verification with altered fields
1463                 let (
1464                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
1465                         mut invoice_tlv_stream, mut signature_tlv_stream
1466                 ) = invoice.as_tlv_stream();
1467                 invoice_request_tlv_stream.amount = Some(2000);
1468                 invoice_tlv_stream.amount = Some(2000);
1469
1470                 let tlv_stream =
1471                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1472                 let mut bytes = Vec::new();
1473                 tlv_stream.write(&mut bytes).unwrap();
1474
1475                 let message = TaggedHash::from_valid_tlv_stream_bytes(INVOICE_SIGNATURE_TAG, &bytes);
1476                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1477                 signature_tlv_stream.signature = Some(&signature);
1478
1479                 let mut encoded_invoice = bytes;
1480                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1481
1482                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1483                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1484
1485                 // Fails verification with altered payer id
1486                 let (
1487                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream, invoice_tlv_stream,
1488                         mut signature_tlv_stream
1489                 ) = invoice.as_tlv_stream();
1490                 let payer_id = pubkey(1);
1491                 invoice_request_tlv_stream.payer_id = Some(&payer_id);
1492
1493                 let tlv_stream =
1494                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1495                 let mut bytes = Vec::new();
1496                 tlv_stream.write(&mut bytes).unwrap();
1497
1498                 let message = TaggedHash::from_valid_tlv_stream_bytes(INVOICE_SIGNATURE_TAG, &bytes);
1499                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1500                 signature_tlv_stream.signature = Some(&signature);
1501
1502                 let mut encoded_invoice = bytes;
1503                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1504
1505                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1506                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1507         }
1508
1509         #[test]
1510         fn builds_invoice_request_with_chain() {
1511                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
1512                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
1513
1514                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1515                         .amount_msats(1000)
1516                         .build().unwrap()
1517                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1518                         .chain(Network::Bitcoin).unwrap()
1519                         .build().unwrap()
1520                         .sign(payer_sign).unwrap();
1521                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1522                 assert_eq!(invoice_request.chain(), mainnet);
1523                 assert_eq!(tlv_stream.chain, None);
1524
1525                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1526                         .amount_msats(1000)
1527                         .chain(Network::Testnet)
1528                         .build().unwrap()
1529                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1530                         .chain(Network::Testnet).unwrap()
1531                         .build().unwrap()
1532                         .sign(payer_sign).unwrap();
1533                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1534                 assert_eq!(invoice_request.chain(), testnet);
1535                 assert_eq!(tlv_stream.chain, Some(&testnet));
1536
1537                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1538                         .amount_msats(1000)
1539                         .chain(Network::Bitcoin)
1540                         .chain(Network::Testnet)
1541                         .build().unwrap()
1542                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1543                         .chain(Network::Bitcoin).unwrap()
1544                         .build().unwrap()
1545                         .sign(payer_sign).unwrap();
1546                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1547                 assert_eq!(invoice_request.chain(), mainnet);
1548                 assert_eq!(tlv_stream.chain, None);
1549
1550                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1551                         .amount_msats(1000)
1552                         .chain(Network::Bitcoin)
1553                         .chain(Network::Testnet)
1554                         .build().unwrap()
1555                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1556                         .chain(Network::Bitcoin).unwrap()
1557                         .chain(Network::Testnet).unwrap()
1558                         .build().unwrap()
1559                         .sign(payer_sign).unwrap();
1560                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1561                 assert_eq!(invoice_request.chain(), testnet);
1562                 assert_eq!(tlv_stream.chain, Some(&testnet));
1563
1564                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1565                         .amount_msats(1000)
1566                         .chain(Network::Testnet)
1567                         .build().unwrap()
1568                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1569                         .chain(Network::Bitcoin)
1570                 {
1571                         Ok(_) => panic!("expected error"),
1572                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
1573                 }
1574
1575                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1576                         .amount_msats(1000)
1577                         .chain(Network::Testnet)
1578                         .build().unwrap()
1579                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1580                         .build()
1581                 {
1582                         Ok(_) => panic!("expected error"),
1583                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
1584                 }
1585         }
1586
1587         #[test]
1588         fn builds_invoice_request_with_amount() {
1589                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1590                         .amount_msats(1000)
1591                         .build().unwrap()
1592                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1593                         .amount_msats(1000).unwrap()
1594                         .build().unwrap()
1595                         .sign(payer_sign).unwrap();
1596                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1597                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1598                 assert_eq!(tlv_stream.amount, Some(1000));
1599
1600                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1601                         .amount_msats(1000)
1602                         .build().unwrap()
1603                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1604                         .amount_msats(1001).unwrap()
1605                         .amount_msats(1000).unwrap()
1606                         .build().unwrap()
1607                         .sign(payer_sign).unwrap();
1608                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1609                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1610                 assert_eq!(tlv_stream.amount, Some(1000));
1611
1612                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1613                         .amount_msats(1000)
1614                         .build().unwrap()
1615                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1616                         .amount_msats(1001).unwrap()
1617                         .build().unwrap()
1618                         .sign(payer_sign).unwrap();
1619                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1620                 assert_eq!(invoice_request.amount_msats(), Some(1001));
1621                 assert_eq!(tlv_stream.amount, Some(1001));
1622
1623                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1624                         .amount_msats(1000)
1625                         .build().unwrap()
1626                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1627                         .amount_msats(999)
1628                 {
1629                         Ok(_) => panic!("expected error"),
1630                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1631                 }
1632
1633                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1634                         .amount_msats(1000)
1635                         .supported_quantity(Quantity::Unbounded)
1636                         .build().unwrap()
1637                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1638                         .quantity(2).unwrap()
1639                         .amount_msats(1000)
1640                 {
1641                         Ok(_) => panic!("expected error"),
1642                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1643                 }
1644
1645                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1646                         .amount_msats(1000)
1647                         .build().unwrap()
1648                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1649                         .amount_msats(MAX_VALUE_MSAT + 1)
1650                 {
1651                         Ok(_) => panic!("expected error"),
1652                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1653                 }
1654
1655                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1656                         .amount_msats(1000)
1657                         .supported_quantity(Quantity::Unbounded)
1658                         .build().unwrap()
1659                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1660                         .amount_msats(1000).unwrap()
1661                         .quantity(2).unwrap()
1662                         .build()
1663                 {
1664                         Ok(_) => panic!("expected error"),
1665                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1666                 }
1667
1668                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1669                         .build().unwrap()
1670                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1671                         .build()
1672                 {
1673                         Ok(_) => panic!("expected error"),
1674                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingAmount),
1675                 }
1676
1677                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1678                         .amount_msats(1000)
1679                         .supported_quantity(Quantity::Unbounded)
1680                         .build().unwrap()
1681                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1682                         .quantity(u64::max_value()).unwrap()
1683                         .build()
1684                 {
1685                         Ok(_) => panic!("expected error"),
1686                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1687                 }
1688         }
1689
1690         #[test]
1691         fn builds_invoice_request_with_features() {
1692                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1693                         .amount_msats(1000)
1694                         .build().unwrap()
1695                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1696                         .features_unchecked(InvoiceRequestFeatures::unknown())
1697                         .build().unwrap()
1698                         .sign(payer_sign).unwrap();
1699                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1700                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::unknown());
1701                 assert_eq!(tlv_stream.features, Some(&InvoiceRequestFeatures::unknown()));
1702
1703                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1704                         .amount_msats(1000)
1705                         .build().unwrap()
1706                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1707                         .features_unchecked(InvoiceRequestFeatures::unknown())
1708                         .features_unchecked(InvoiceRequestFeatures::empty())
1709                         .build().unwrap()
1710                         .sign(payer_sign).unwrap();
1711                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1712                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
1713                 assert_eq!(tlv_stream.features, None);
1714         }
1715
1716         #[test]
1717         fn builds_invoice_request_with_quantity() {
1718                 let one = NonZeroU64::new(1).unwrap();
1719                 let ten = NonZeroU64::new(10).unwrap();
1720
1721                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1722                         .amount_msats(1000)
1723                         .supported_quantity(Quantity::One)
1724                         .build().unwrap()
1725                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1726                         .build().unwrap()
1727                         .sign(payer_sign).unwrap();
1728                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1729                 assert_eq!(invoice_request.quantity(), None);
1730                 assert_eq!(tlv_stream.quantity, None);
1731
1732                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1733                         .amount_msats(1000)
1734                         .supported_quantity(Quantity::One)
1735                         .build().unwrap()
1736                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1737                         .amount_msats(2_000).unwrap()
1738                         .quantity(2)
1739                 {
1740                         Ok(_) => panic!("expected error"),
1741                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnexpectedQuantity),
1742                 }
1743
1744                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1745                         .amount_msats(1000)
1746                         .supported_quantity(Quantity::Bounded(ten))
1747                         .build().unwrap()
1748                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1749                         .amount_msats(10_000).unwrap()
1750                         .quantity(10).unwrap()
1751                         .build().unwrap()
1752                         .sign(payer_sign).unwrap();
1753                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1754                 assert_eq!(invoice_request.amount_msats(), Some(10_000));
1755                 assert_eq!(tlv_stream.amount, Some(10_000));
1756
1757                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1758                         .amount_msats(1000)
1759                         .supported_quantity(Quantity::Bounded(ten))
1760                         .build().unwrap()
1761                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1762                         .amount_msats(11_000).unwrap()
1763                         .quantity(11)
1764                 {
1765                         Ok(_) => panic!("expected error"),
1766                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidQuantity),
1767                 }
1768
1769                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1770                         .amount_msats(1000)
1771                         .supported_quantity(Quantity::Unbounded)
1772                         .build().unwrap()
1773                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1774                         .amount_msats(2_000).unwrap()
1775                         .quantity(2).unwrap()
1776                         .build().unwrap()
1777                         .sign(payer_sign).unwrap();
1778                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1779                 assert_eq!(invoice_request.amount_msats(), Some(2_000));
1780                 assert_eq!(tlv_stream.amount, Some(2_000));
1781
1782                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1783                         .amount_msats(1000)
1784                         .supported_quantity(Quantity::Unbounded)
1785                         .build().unwrap()
1786                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1787                         .build()
1788                 {
1789                         Ok(_) => panic!("expected error"),
1790                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
1791                 }
1792
1793                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1794                         .amount_msats(1000)
1795                         .supported_quantity(Quantity::Bounded(one))
1796                         .build().unwrap()
1797                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1798                         .build()
1799                 {
1800                         Ok(_) => panic!("expected error"),
1801                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
1802                 }
1803         }
1804
1805         #[test]
1806         fn builds_invoice_request_with_payer_note() {
1807                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1808                         .amount_msats(1000)
1809                         .build().unwrap()
1810                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1811                         .payer_note("bar".into())
1812                         .build().unwrap()
1813                         .sign(payer_sign).unwrap();
1814                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1815                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("bar")));
1816                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
1817
1818                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1819                         .amount_msats(1000)
1820                         .build().unwrap()
1821                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1822                         .payer_note("bar".into())
1823                         .payer_note("baz".into())
1824                         .build().unwrap()
1825                         .sign(payer_sign).unwrap();
1826                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1827                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("baz")));
1828                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
1829         }
1830
1831         #[test]
1832         fn fails_signing_invoice_request() {
1833                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1834                         .amount_msats(1000)
1835                         .build().unwrap()
1836                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1837                         .build().unwrap()
1838                         .sign(fail_sign)
1839                 {
1840                         Ok(_) => panic!("expected error"),
1841                         Err(e) => assert_eq!(e, SignError::Signing),
1842                 }
1843
1844                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1845                         .amount_msats(1000)
1846                         .build().unwrap()
1847                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1848                         .build().unwrap()
1849                         .sign(recipient_sign)
1850                 {
1851                         Ok(_) => panic!("expected error"),
1852                         Err(e) => assert_eq!(e, SignError::Verification(secp256k1::Error::InvalidSignature)),
1853                 }
1854         }
1855
1856         #[test]
1857         fn fails_responding_with_unknown_required_features() {
1858                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1859                         .amount_msats(1000)
1860                         .build().unwrap()
1861                         .request_invoice(vec![42; 32], payer_pubkey()).unwrap()
1862                         .features_unchecked(InvoiceRequestFeatures::unknown())
1863                         .build().unwrap()
1864                         .sign(payer_sign).unwrap()
1865                         .respond_with_no_std(payment_paths(), payment_hash(), now())
1866                 {
1867                         Ok(_) => panic!("expected error"),
1868                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1869                 }
1870         }
1871
1872         #[test]
1873         fn parses_invoice_request_with_metadata() {
1874                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1875                         .amount_msats(1000)
1876                         .build().unwrap()
1877                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1878                         .build().unwrap()
1879                         .sign(payer_sign).unwrap();
1880
1881                 let mut buffer = Vec::new();
1882                 invoice_request.write(&mut buffer).unwrap();
1883
1884                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1885                         panic!("error parsing invoice_request: {:?}", e);
1886                 }
1887         }
1888
1889         #[test]
1890         fn parses_invoice_request_with_chain() {
1891                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1892                         .amount_msats(1000)
1893                         .build().unwrap()
1894                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1895                         .chain(Network::Bitcoin).unwrap()
1896                         .build().unwrap()
1897                         .sign(payer_sign).unwrap();
1898
1899                 let mut buffer = Vec::new();
1900                 invoice_request.write(&mut buffer).unwrap();
1901
1902                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1903                         panic!("error parsing invoice_request: {:?}", e);
1904                 }
1905
1906                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1907                         .amount_msats(1000)
1908                         .build().unwrap()
1909                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1910                         .chain_unchecked(Network::Testnet)
1911                         .build_unchecked()
1912                         .sign(payer_sign).unwrap();
1913
1914                 let mut buffer = Vec::new();
1915                 invoice_request.write(&mut buffer).unwrap();
1916
1917                 match InvoiceRequest::try_from(buffer) {
1918                         Ok(_) => panic!("expected error"),
1919                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnsupportedChain)),
1920                 }
1921         }
1922
1923         #[test]
1924         fn parses_invoice_request_with_amount() {
1925                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1926                         .amount_msats(1000)
1927                         .build().unwrap()
1928                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1929                         .build().unwrap()
1930                         .sign(payer_sign).unwrap();
1931
1932                 let mut buffer = Vec::new();
1933                 invoice_request.write(&mut buffer).unwrap();
1934
1935                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1936                         panic!("error parsing invoice_request: {:?}", e);
1937                 }
1938
1939                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1940                         .build().unwrap()
1941                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1942                         .amount_msats(1000).unwrap()
1943                         .build().unwrap()
1944                         .sign(payer_sign).unwrap();
1945
1946                 let mut buffer = Vec::new();
1947                 invoice_request.write(&mut buffer).unwrap();
1948
1949                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1950                         panic!("error parsing invoice_request: {:?}", e);
1951                 }
1952
1953                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1954                         .build().unwrap()
1955                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1956                         .build_unchecked()
1957                         .sign(payer_sign).unwrap();
1958
1959                 let mut buffer = Vec::new();
1960                 invoice_request.write(&mut buffer).unwrap();
1961
1962                 match InvoiceRequest::try_from(buffer) {
1963                         Ok(_) => panic!("expected error"),
1964                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1965                 }
1966
1967                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1968                         .amount_msats(1000)
1969                         .build().unwrap()
1970                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1971                         .amount_msats_unchecked(999)
1972                         .build_unchecked()
1973                         .sign(payer_sign).unwrap();
1974
1975                 let mut buffer = Vec::new();
1976                 invoice_request.write(&mut buffer).unwrap();
1977
1978                 match InvoiceRequest::try_from(buffer) {
1979                         Ok(_) => panic!("expected error"),
1980                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InsufficientAmount)),
1981                 }
1982
1983                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1984                         .amount(Amount::Currency { iso4217_code: *b"USD", amount: 1000 })
1985                         .build_unchecked()
1986                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1987                         .build_unchecked()
1988                         .sign(payer_sign).unwrap();
1989
1990                 let mut buffer = Vec::new();
1991                 invoice_request.write(&mut buffer).unwrap();
1992
1993                 match InvoiceRequest::try_from(buffer) {
1994                         Ok(_) => panic!("expected error"),
1995                         Err(e) => {
1996                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnsupportedCurrency));
1997                         },
1998                 }
1999
2000                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2001                         .amount_msats(1000)
2002                         .supported_quantity(Quantity::Unbounded)
2003                         .build().unwrap()
2004                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2005                         .quantity(u64::max_value()).unwrap()
2006                         .build_unchecked()
2007                         .sign(payer_sign).unwrap();
2008
2009                 let mut buffer = Vec::new();
2010                 invoice_request.write(&mut buffer).unwrap();
2011
2012                 match InvoiceRequest::try_from(buffer) {
2013                         Ok(_) => panic!("expected error"),
2014                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
2015                 }
2016         }
2017
2018         #[test]
2019         fn parses_invoice_request_with_quantity() {
2020                 let one = NonZeroU64::new(1).unwrap();
2021                 let ten = NonZeroU64::new(10).unwrap();
2022
2023                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2024                         .amount_msats(1000)
2025                         .supported_quantity(Quantity::One)
2026                         .build().unwrap()
2027                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2028                         .build().unwrap()
2029                         .sign(payer_sign).unwrap();
2030
2031                 let mut buffer = Vec::new();
2032                 invoice_request.write(&mut buffer).unwrap();
2033
2034                 if let Err(e) = InvoiceRequest::try_from(buffer) {
2035                         panic!("error parsing invoice_request: {:?}", e);
2036                 }
2037
2038                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2039                         .amount_msats(1000)
2040                         .supported_quantity(Quantity::One)
2041                         .build().unwrap()
2042                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2043                         .amount_msats(2_000).unwrap()
2044                         .quantity_unchecked(2)
2045                         .build_unchecked()
2046                         .sign(payer_sign).unwrap();
2047
2048                 let mut buffer = Vec::new();
2049                 invoice_request.write(&mut buffer).unwrap();
2050
2051                 match InvoiceRequest::try_from(buffer) {
2052                         Ok(_) => panic!("expected error"),
2053                         Err(e) => {
2054                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnexpectedQuantity));
2055                         },
2056                 }
2057
2058                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2059                         .amount_msats(1000)
2060                         .supported_quantity(Quantity::Bounded(ten))
2061                         .build().unwrap()
2062                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2063                         .amount_msats(10_000).unwrap()
2064                         .quantity(10).unwrap()
2065                         .build().unwrap()
2066                         .sign(payer_sign).unwrap();
2067
2068                 let mut buffer = Vec::new();
2069                 invoice_request.write(&mut buffer).unwrap();
2070
2071                 if let Err(e) = InvoiceRequest::try_from(buffer) {
2072                         panic!("error parsing invoice_request: {:?}", e);
2073                 }
2074
2075                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2076                         .amount_msats(1000)
2077                         .supported_quantity(Quantity::Bounded(ten))
2078                         .build().unwrap()
2079                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2080                         .amount_msats(11_000).unwrap()
2081                         .quantity_unchecked(11)
2082                         .build_unchecked()
2083                         .sign(payer_sign).unwrap();
2084
2085                 let mut buffer = Vec::new();
2086                 invoice_request.write(&mut buffer).unwrap();
2087
2088                 match InvoiceRequest::try_from(buffer) {
2089                         Ok(_) => panic!("expected error"),
2090                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidQuantity)),
2091                 }
2092
2093                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2094                         .amount_msats(1000)
2095                         .supported_quantity(Quantity::Unbounded)
2096                         .build().unwrap()
2097                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2098                         .amount_msats(2_000).unwrap()
2099                         .quantity(2).unwrap()
2100                         .build().unwrap()
2101                         .sign(payer_sign).unwrap();
2102
2103                 let mut buffer = Vec::new();
2104                 invoice_request.write(&mut buffer).unwrap();
2105
2106                 if let Err(e) = InvoiceRequest::try_from(buffer) {
2107                         panic!("error parsing invoice_request: {:?}", e);
2108                 }
2109
2110                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2111                         .amount_msats(1000)
2112                         .supported_quantity(Quantity::Unbounded)
2113                         .build().unwrap()
2114                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2115                         .build_unchecked()
2116                         .sign(payer_sign).unwrap();
2117
2118                 let mut buffer = Vec::new();
2119                 invoice_request.write(&mut buffer).unwrap();
2120
2121                 match InvoiceRequest::try_from(buffer) {
2122                         Ok(_) => panic!("expected error"),
2123                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
2124                 }
2125
2126                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2127                         .amount_msats(1000)
2128                         .supported_quantity(Quantity::Bounded(one))
2129                         .build().unwrap()
2130                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2131                         .build_unchecked()
2132                         .sign(payer_sign).unwrap();
2133
2134                 let mut buffer = Vec::new();
2135                 invoice_request.write(&mut buffer).unwrap();
2136
2137                 match InvoiceRequest::try_from(buffer) {
2138                         Ok(_) => panic!("expected error"),
2139                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
2140                 }
2141         }
2142
2143         #[test]
2144         fn fails_parsing_invoice_request_without_metadata() {
2145                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
2146                         .amount_msats(1000)
2147                         .build().unwrap();
2148                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2149                         .build().unwrap();
2150                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
2151                 tlv_stream.0.metadata = None;
2152
2153                 let mut buffer = Vec::new();
2154                 tlv_stream.write(&mut buffer).unwrap();
2155
2156                 match InvoiceRequest::try_from(buffer) {
2157                         Ok(_) => panic!("expected error"),
2158                         Err(e) => {
2159                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPayerMetadata));
2160                         },
2161                 }
2162         }
2163
2164         #[test]
2165         fn fails_parsing_invoice_request_without_payer_id() {
2166                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
2167                         .amount_msats(1000)
2168                         .build().unwrap();
2169                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2170                         .build().unwrap();
2171                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
2172                 tlv_stream.2.payer_id = None;
2173
2174                 let mut buffer = Vec::new();
2175                 tlv_stream.write(&mut buffer).unwrap();
2176
2177                 match InvoiceRequest::try_from(buffer) {
2178                         Ok(_) => panic!("expected error"),
2179                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPayerId)),
2180                 }
2181         }
2182
2183         #[test]
2184         fn fails_parsing_invoice_request_without_node_id() {
2185                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
2186                         .amount_msats(1000)
2187                         .build().unwrap();
2188                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2189                         .build().unwrap();
2190                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
2191                 tlv_stream.1.node_id = None;
2192
2193                 let mut buffer = Vec::new();
2194                 tlv_stream.write(&mut buffer).unwrap();
2195
2196                 match InvoiceRequest::try_from(buffer) {
2197                         Ok(_) => panic!("expected error"),
2198                         Err(e) => {
2199                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
2200                         },
2201                 }
2202         }
2203
2204         #[test]
2205         fn fails_parsing_invoice_request_without_signature() {
2206                 let mut buffer = Vec::new();
2207                 OfferBuilder::new("foo".into(), recipient_pubkey())
2208                         .amount_msats(1000)
2209                         .build().unwrap()
2210                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2211                         .build().unwrap()
2212                         .contents
2213                         .write(&mut buffer).unwrap();
2214
2215                 match InvoiceRequest::try_from(buffer) {
2216                         Ok(_) => panic!("expected error"),
2217                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
2218                 }
2219         }
2220
2221         #[test]
2222         fn fails_parsing_invoice_request_with_invalid_signature() {
2223                 let mut invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2224                         .amount_msats(1000)
2225                         .build().unwrap()
2226                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2227                         .build().unwrap()
2228                         .sign(payer_sign).unwrap();
2229                 let last_signature_byte = invoice_request.bytes.last_mut().unwrap();
2230                 *last_signature_byte = last_signature_byte.wrapping_add(1);
2231
2232                 let mut buffer = Vec::new();
2233                 invoice_request.write(&mut buffer).unwrap();
2234
2235                 match InvoiceRequest::try_from(buffer) {
2236                         Ok(_) => panic!("expected error"),
2237                         Err(e) => {
2238                                 assert_eq!(e, Bolt12ParseError::InvalidSignature(secp256k1::Error::InvalidSignature));
2239                         },
2240                 }
2241         }
2242
2243         #[test]
2244         fn fails_parsing_invoice_request_with_extra_tlv_records() {
2245                 let secp_ctx = Secp256k1::new();
2246                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2247                 let invoice_request = OfferBuilder::new("foo".into(), keys.public_key())
2248                         .amount_msats(1000)
2249                         .build().unwrap()
2250                         .request_invoice(vec![1; 32], keys.public_key()).unwrap()
2251                         .build().unwrap()
2252                         .sign(|message: &UnsignedInvoiceRequest|
2253                                 Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
2254                         )
2255                         .unwrap();
2256
2257                 let mut encoded_invoice_request = Vec::new();
2258                 invoice_request.write(&mut encoded_invoice_request).unwrap();
2259                 BigSize(1002).write(&mut encoded_invoice_request).unwrap();
2260                 BigSize(32).write(&mut encoded_invoice_request).unwrap();
2261                 [42u8; 32].write(&mut encoded_invoice_request).unwrap();
2262
2263                 match InvoiceRequest::try_from(encoded_invoice_request) {
2264                         Ok(_) => panic!("expected error"),
2265                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
2266                 }
2267         }
2268
2269         #[test]
2270         fn copies_verified_invoice_request_fields() {
2271                 let desc = "foo".to_string();
2272                 let node_id = recipient_pubkey();
2273                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
2274                 let entropy = FixedEntropy {};
2275                 let secp_ctx = Secp256k1::new();
2276
2277                 #[cfg(c_bindings)]
2278                 use crate::offers::offer::OfferWithDerivedMetadataBuilder as OfferBuilder;
2279                 let offer = OfferBuilder
2280                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
2281                         .chain(Network::Testnet)
2282                         .amount_msats(1000)
2283                         .supported_quantity(Quantity::Unbounded)
2284                         .build().unwrap();
2285                 assert_eq!(offer.signing_pubkey(), Some(node_id));
2286
2287                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2288                         .chain(Network::Testnet).unwrap()
2289                         .quantity(1).unwrap()
2290                         .payer_note("0".repeat(PAYER_NOTE_LIMIT * 2))
2291                         .build().unwrap()
2292                         .sign(payer_sign).unwrap();
2293                 match invoice_request.verify(&expanded_key, &secp_ctx) {
2294                         Ok(invoice_request) => {
2295                                 let fields = invoice_request.fields();
2296                                 assert_eq!(invoice_request.offer_id, offer.id());
2297                                 assert_eq!(
2298                                         fields,
2299                                         InvoiceRequestFields {
2300                                                 payer_id: payer_pubkey(),
2301                                                 quantity: Some(1),
2302                                                 payer_note_truncated: Some(UntrustedString("0".repeat(PAYER_NOTE_LIMIT))),
2303                                         }
2304                                 );
2305
2306                                 let mut buffer = Vec::new();
2307                                 fields.write(&mut buffer).unwrap();
2308
2309                                 let deserialized_fields: InvoiceRequestFields =
2310                                         Readable::read(&mut buffer.as_slice()).unwrap();
2311                                 assert_eq!(deserialized_fields, fields);
2312                         },
2313                         Err(_) => panic!("unexpected error"),
2314                 }
2315         }
2316 }