_ 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 core::convert::Infallible;
  29 //! use lightning::ln::features::OfferFeatures;
  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 //! "lno1qcp4256ypq"
  40 //!     .parse::<Offer>()?
  41 //!     .request_invoice(vec![42; 64], pubkey)?
  42 //!     .chain(Network::Testnet)?
  43 //!     .amount_msats(1000)?
  44 //!     .quantity(5)?
  45 //!     .payer_note("foo".to_string())
  46 //!     .build()?
  47 //!     .sign::<_, Infallible>(|digest| Ok(secp_ctx.sign_schnorr_no_aux_rand(digest, &keys)))
  48 //!     .expect("failed verifying signature")
  49 //!     .write(&mut buffer)
  50 //!     .unwrap();
  51 //! # Ok(())
  52 //! # }
  53 //! ```
  54
  55 use bitcoin::blockdata::constants::ChainHash;
  56 use bitcoin::network::constants::Network;
  57 use bitcoin::secp256k1::{KeyPair, Message, PublicKey, Secp256k1, self};
  58 use bitcoin::secp256k1::schnorr::Signature;
  59 use core::convert::{Infallible, TryFrom};
  60 use core::ops::Deref;
  61 use crate::sign::EntropySource;
  62 use crate::io;
  63 use crate::blinded_path::BlindedPath;
  64 use crate::ln::PaymentHash;
  65 use crate::ln::features::InvoiceRequestFeatures;
  66 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
  67 use crate::ln::msgs::DecodeError;
  68 use crate::offers::invoice::{BlindedPayInfo, DerivedSigningPubkey, ExplicitSigningPubkey, InvoiceBuilder};
  69 use crate::offers::merkle::{SignError, SignatureTlvStream, SignatureTlvStreamRef, self};
  70 use crate::offers::offer::{Offer, OfferContents, OfferTlvStream, OfferTlvStreamRef};
  71 use crate::offers::parse::{Bolt12ParseError, ParsedMessage, Bolt12SemanticError};
  72 use crate::offers::payer::{PayerContents, PayerTlvStream, PayerTlvStreamRef};
  73 use crate::offers::signer::{Metadata, MetadataMaterial};
  74 use crate::util::ser::{HighZeroBytesDroppedBigSize, SeekReadable, WithoutLength, Writeable, Writer};
  75 use crate::util::string::PrintableString;
  76
  77 use crate::prelude::*;
  78
  79 const SIGNATURE_TAG: &'static str = concat!("lightning", "invoice_request", "signature");
  80
  81 pub(super) const IV_BYTES: &[u8; IV_LEN] = b"LDK Invreq ~~~~~";
  82
  83 /// Builds an [`InvoiceRequest`] from an [`Offer`] for the "offer to be paid" flow.
  84 ///
  85 /// See [module-level documentation] for usage.
  86 ///
  87 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
  88 ///
  89 /// [module-level documentation]: self
  90 pub struct InvoiceRequestBuilder<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> {
  91         offer: &'a Offer,
  92         invoice_request: InvoiceRequestContentsWithoutPayerId,
  93         payer_id: Option<PublicKey>,
  94         payer_id_strategy: core::marker::PhantomData<P>,
  95         secp_ctx: Option<&'b Secp256k1<T>>,
  96 }
  97
  98 /// Indicates how [`InvoiceRequest::payer_id`] will be set.
  99 ///
 100 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 101 pub trait PayerIdStrategy {}
 102
 103 /// [`InvoiceRequest::payer_id`] will be explicitly set.
 104 ///
 105 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 106 pub struct ExplicitPayerId {}
 107
 108 /// [`InvoiceRequest::payer_id`] will be derived.
 109 ///
 110 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 111 pub struct DerivedPayerId {}
 112
 113 impl PayerIdStrategy for ExplicitPayerId {}
 114 impl PayerIdStrategy for DerivedPayerId {}
 115
 116 impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, ExplicitPayerId, T> {
 117         pub(super) fn new(offer: &'a Offer, metadata: Vec<u8>, payer_id: PublicKey) -> Self {
 118                 Self {
 119                         offer,
 120                         invoice_request: Self::create_contents(offer, Metadata::Bytes(metadata)),
 121                         payer_id: Some(payer_id),
 122                         payer_id_strategy: core::marker::PhantomData,
 123                         secp_ctx: None,
 124                 }
 125         }
 126
 127         pub(super) fn deriving_metadata<ES: Deref>(
 128                 offer: &'a Offer, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES
 129         ) -> Self where ES::Target: EntropySource {
 130                 let nonce = Nonce::from_entropy_source(entropy_source);
 131                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES);
 132                 let metadata = Metadata::Derived(derivation_material);
 133                 Self {
 134                         offer,
 135                         invoice_request: Self::create_contents(offer, metadata),
 136                         payer_id: Some(payer_id),
 137                         payer_id_strategy: core::marker::PhantomData,
 138                         secp_ctx: None,
 139                 }
 140         }
 141 }
 142
 143 impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T> {
 144         pub(super) fn deriving_payer_id<ES: Deref>(
 145                 offer: &'a Offer, expanded_key: &ExpandedKey, entropy_source: ES, secp_ctx: &'b Secp256k1<T>
 146         ) -> Self where ES::Target: EntropySource {
 147                 let nonce = Nonce::from_entropy_source(entropy_source);
 148                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES);
 149                 let metadata = Metadata::DerivedSigningPubkey(derivation_material);
 150                 Self {
 151                         offer,
 152                         invoice_request: Self::create_contents(offer, metadata),
 153                         payer_id: None,
 154                         payer_id_strategy: core::marker::PhantomData,
 155                         secp_ctx: Some(secp_ctx),
 156                 }
 157         }
 158 }
 159
 160 impl<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, P, T> {
 161         fn create_contents(offer: &Offer, metadata: Metadata) -> InvoiceRequestContentsWithoutPayerId {
 162                 let offer = offer.contents.clone();
 163                 InvoiceRequestContentsWithoutPayerId {
 164                         payer: PayerContents(metadata), offer, chain: None, amount_msats: None,
 165                         features: InvoiceRequestFeatures::empty(), quantity: None, payer_note: None,
 166                 }
 167         }
 168
 169         /// Sets the [`InvoiceRequest::chain`] of the given [`Network`] for paying an invoice. If not
 170         /// called, [`Network::Bitcoin`] is assumed. Errors if the chain for `network` is not supported
 171         /// by the offer.
 172         ///
 173         /// Successive calls to this method will override the previous setting.
 174         pub fn chain(mut self, network: Network) -> Result<Self, Bolt12SemanticError> {
 175                 let chain = ChainHash::using_genesis_block(network);
 176                 if !self.offer.supports_chain(chain) {
 177                         return Err(Bolt12SemanticError::UnsupportedChain);
 178                 }
 179
 180                 self.invoice_request.chain = Some(chain);
 181                 Ok(self)
 182         }
 183
 184         /// Sets the [`InvoiceRequest::amount_msats`] for paying an invoice. Errors if `amount_msats` is
 185         /// not at least the expected invoice amount (i.e., [`Offer::amount`] times [`quantity`]).
 186         ///
 187         /// Successive calls to this method will override the previous setting.
 188         ///
 189         /// [`quantity`]: Self::quantity
 190         pub fn amount_msats(mut self, amount_msats: u64) -> Result<Self, Bolt12SemanticError> {
 191                 self.invoice_request.offer.check_amount_msats_for_quantity(
 192                         Some(amount_msats), self.invoice_request.quantity
 193                 )?;
 194                 self.invoice_request.amount_msats = Some(amount_msats);
 195                 Ok(self)
 196         }
 197
 198         /// Sets [`InvoiceRequest::quantity`] of items. If not set, `1` is assumed. Errors if `quantity`
 199         /// does not conform to [`Offer::is_valid_quantity`].
 200         ///
 201         /// Successive calls to this method will override the previous setting.
 202         pub fn quantity(mut self, quantity: u64) -> Result<Self, Bolt12SemanticError> {
 203                 self.invoice_request.offer.check_quantity(Some(quantity))?;
 204                 self.invoice_request.quantity = Some(quantity);
 205                 Ok(self)
 206         }
 207
 208         /// Sets the [`InvoiceRequest::payer_note`].
 209         ///
 210         /// Successive calls to this method will override the previous setting.
 211         pub fn payer_note(mut self, payer_note: String) -> Self {
 212                 self.invoice_request.payer_note = Some(payer_note);
 213                 self
 214         }
 215
 216         fn build_with_checks(mut self) -> Result<
 217                 (UnsignedInvoiceRequest<'a>, Option<KeyPair>, Option<&'b Secp256k1<T>>),
 218                 Bolt12SemanticError
 219         > {
 220                 #[cfg(feature = "std")] {
 221                         if self.offer.is_expired() {
 222                                 return Err(Bolt12SemanticError::AlreadyExpired);
 223                         }
 224                 }
 225
 226                 let chain = self.invoice_request.chain();
 227                 if !self.offer.supports_chain(chain) {
 228                         return Err(Bolt12SemanticError::UnsupportedChain);
 229                 }
 230
 231                 if chain == self.offer.implied_chain() {
 232                         self.invoice_request.chain = None;
 233                 }
 234
 235                 if self.offer.amount().is_none() && self.invoice_request.amount_msats.is_none() {
 236                         return Err(Bolt12SemanticError::MissingAmount);
 237                 }
 238
 239                 self.invoice_request.offer.check_quantity(self.invoice_request.quantity)?;
 240                 self.invoice_request.offer.check_amount_msats_for_quantity(
 241                         self.invoice_request.amount_msats, self.invoice_request.quantity
 242                 )?;
 243
 244                 Ok(self.build_without_checks())
 245         }
 246
 247         fn build_without_checks(mut self) ->
 248                 (UnsignedInvoiceRequest<'a>, Option<KeyPair>, Option<&'b Secp256k1<T>>)
 249         {
 250                 // Create the metadata for stateless verification of a Bolt12Invoice.
 251                 let mut keys = None;
 252                 let secp_ctx = self.secp_ctx.clone();
 253                 if self.invoice_request.payer.0.has_derivation_material() {
 254                         let mut metadata = core::mem::take(&mut self.invoice_request.payer.0);
 255
 256                         let mut tlv_stream = self.invoice_request.as_tlv_stream();
 257                         debug_assert!(tlv_stream.2.payer_id.is_none());
 258                         tlv_stream.0.metadata = None;
 259                         if !metadata.derives_keys() {
 260                                 tlv_stream.2.payer_id = self.payer_id.as_ref();
 261                         }
 262
 263                         let (derived_metadata, derived_keys) = metadata.derive_from(tlv_stream, self.secp_ctx);
 264                         metadata = derived_metadata;
 265                         keys = derived_keys;
 266                         if let Some(keys) = keys {
 267                                 debug_assert!(self.payer_id.is_none());
 268                                 self.payer_id = Some(keys.public_key());
 269                         }
 270
 271                         self.invoice_request.payer.0 = metadata;
 272                 }
 273
 274                 debug_assert!(self.invoice_request.payer.0.as_bytes().is_some());
 275                 debug_assert!(self.payer_id.is_some());
 276                 let payer_id = self.payer_id.unwrap();
 277
 278                 let unsigned_invoice = UnsignedInvoiceRequest {
 279                         offer: self.offer,
 280                         invoice_request: InvoiceRequestContents {
 281                                 inner: self.invoice_request,
 282                                 payer_id,
 283                         },
 284                 };
 285
 286                 (unsigned_invoice, keys, secp_ctx)
 287         }
 288 }
 289
 290 impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, ExplicitPayerId, T> {
 291         /// Builds an unsigned [`InvoiceRequest`] after checking for valid semantics. It can be signed
 292         /// by [`UnsignedInvoiceRequest::sign`].
 293         pub fn build(self) -> Result<UnsignedInvoiceRequest<'a>, Bolt12SemanticError> {
 294                 let (unsigned_invoice_request, keys, _) = self.build_with_checks()?;
 295                 debug_assert!(keys.is_none());
 296                 Ok(unsigned_invoice_request)
 297         }
 298 }
 299
 300 impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T> {
 301         /// Builds a signed [`InvoiceRequest`] after checking for valid semantics.
 302         pub fn build_and_sign(self) -> Result<InvoiceRequest, Bolt12SemanticError> {
 303                 let (unsigned_invoice_request, keys, secp_ctx) = self.build_with_checks()?;
 304                 debug_assert!(keys.is_some());
 305
 306                 let secp_ctx = secp_ctx.unwrap();
 307                 let keys = keys.unwrap();
 308                 let invoice_request = unsigned_invoice_request
 309                         .sign::<_, Infallible>(|digest| Ok(secp_ctx.sign_schnorr_no_aux_rand(digest, &keys)))
 310                         .unwrap();
 311                 Ok(invoice_request)
 312         }
 313 }
 314
 315 #[cfg(test)]
 316 impl<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, P, T> {
 317         fn chain_unchecked(mut self, network: Network) -> Self {
 318                 let chain = ChainHash::using_genesis_block(network);
 319                 self.invoice_request.chain = Some(chain);
 320                 self
 321         }
 322
 323         fn amount_msats_unchecked(mut self, amount_msats: u64) -> Self {
 324                 self.invoice_request.amount_msats = Some(amount_msats);
 325                 self
 326         }
 327
 328         fn features_unchecked(mut self, features: InvoiceRequestFeatures) -> Self {
 329                 self.invoice_request.features = features;
 330                 self
 331         }
 332
 333         fn quantity_unchecked(mut self, quantity: u64) -> Self {
 334                 self.invoice_request.quantity = Some(quantity);
 335                 self
 336         }
 337
 338         pub(super) fn build_unchecked(self) -> UnsignedInvoiceRequest<'a> {
 339                 self.build_without_checks().0
 340         }
 341 }
 342
 343 /// A semantically valid [`InvoiceRequest`] that hasn't been signed.
 344 pub struct UnsignedInvoiceRequest<'a> {
 345         offer: &'a Offer,
 346         invoice_request: InvoiceRequestContents,
 347 }
 348
 349 impl<'a> UnsignedInvoiceRequest<'a> {
 350         /// Signs the invoice request using the given function.
 351         ///
 352         /// This is not exported to bindings users as functions are not yet mapped.
 353         pub fn sign<F, E>(self, sign: F) -> Result<InvoiceRequest, SignError<E>>
 354         where
 355                 F: FnOnce(&Message) -> Result<Signature, E>
 356         {
 357                 // Use the offer bytes instead of the offer TLV stream as the offer may have contained
 358                 // unknown TLV records, which are not stored in `OfferContents`.
 359                 let (payer_tlv_stream, _offer_tlv_stream, invoice_request_tlv_stream) =
 360                         self.invoice_request.as_tlv_stream();
 361                 let offer_bytes = WithoutLength(&self.offer.bytes);
 362                 let unsigned_tlv_stream = (payer_tlv_stream, offer_bytes, invoice_request_tlv_stream);
 363
 364                 let mut bytes = Vec::new();
 365                 unsigned_tlv_stream.write(&mut bytes).unwrap();
 366
 367                 let pubkey = self.invoice_request.payer_id;
 368                 let signature = merkle::sign_message(sign, SIGNATURE_TAG, &bytes, pubkey)?;
 369
 370                 // Append the signature TLV record to the bytes.
 371                 let signature_tlv_stream = SignatureTlvStreamRef {
 372                         signature: Some(&signature),
 373                 };
 374                 signature_tlv_stream.write(&mut bytes).unwrap();
 375
 376                 Ok(InvoiceRequest {
 377                         bytes,
 378                         contents: self.invoice_request,
 379                         signature,
 380                 })
 381         }
 382 }
 383
 384 /// An `InvoiceRequest` is a request for a [`Bolt12Invoice`] formulated from an [`Offer`].
 385 ///
 386 /// An offer may provide choices such as quantity, amount, chain, features, etc. An invoice request
 387 /// specifies these such that its recipient can send an invoice for payment.
 388 ///
 389 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 390 /// [`Offer`]: crate::offers::offer::Offer
 391 #[derive(Clone, Debug)]
 392 #[cfg_attr(test, derive(PartialEq))]
 393 pub struct InvoiceRequest {
 394         pub(super) bytes: Vec<u8>,
 395         pub(super) contents: InvoiceRequestContents,
 396         signature: Signature,
 397 }
 398
 399 /// The contents of an [`InvoiceRequest`], which may be shared with an [`Bolt12Invoice`].
 400 ///
 401 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 402 #[derive(Clone, Debug)]
 403 #[cfg_attr(test, derive(PartialEq))]
 404 pub(super) struct InvoiceRequestContents {
 405         pub(super) inner: InvoiceRequestContentsWithoutPayerId,
 406         payer_id: PublicKey,
 407 }
 408
 409 #[derive(Clone, Debug)]
 410 #[cfg_attr(test, derive(PartialEq))]
 411 pub(super) struct InvoiceRequestContentsWithoutPayerId {
 412         payer: PayerContents,
 413         pub(super) offer: OfferContents,
 414         chain: Option<ChainHash>,
 415         amount_msats: Option<u64>,
 416         features: InvoiceRequestFeatures,
 417         quantity: Option<u64>,
 418         payer_note: Option<String>,
 419 }
 420
 421 impl InvoiceRequest {
 422         /// An unpredictable series of bytes, typically containing information about the derivation of
 423         /// [`payer_id`].
 424         ///
 425         /// [`payer_id`]: Self::payer_id
 426         pub fn metadata(&self) -> &[u8] {
 427                 self.contents.metadata()
 428         }
 429
 430         /// A chain from [`Offer::chains`] that the offer is valid for.
 431         pub fn chain(&self) -> ChainHash {
 432                 self.contents.chain()
 433         }
 434
 435         /// The amount to pay in msats (i.e., the minimum lightning-payable unit for [`chain`]), which
 436         /// must be greater than or equal to [`Offer::amount`], converted if necessary.
 437         ///
 438         /// [`chain`]: Self::chain
 439         pub fn amount_msats(&self) -> Option<u64> {
 440                 self.contents.inner.amount_msats
 441         }
 442
 443         /// Features pertaining to requesting an invoice.
 444         pub fn features(&self) -> &InvoiceRequestFeatures {
 445                 &self.contents.inner.features
 446         }
 447
 448         /// The quantity of the offer's item conforming to [`Offer::is_valid_quantity`].
 449         pub fn quantity(&self) -> Option<u64> {
 450                 self.contents.inner.quantity
 451         }
 452
 453         /// A possibly transient pubkey used to sign the invoice request.
 454         pub fn payer_id(&self) -> PublicKey {
 455                 self.contents.payer_id
 456         }
 457
 458         /// A payer-provided note which will be seen by the recipient and reflected back in the invoice
 459         /// response.
 460         pub fn payer_note(&self) -> Option<PrintableString> {
 461                 self.contents.inner.payer_note.as_ref()
 462                         .map(|payer_note| PrintableString(payer_note.as_str()))
 463         }
 464
 465         /// Signature of the invoice request using [`payer_id`].
 466         ///
 467         /// This is not exported to bindings users as Signature is not yet mapped.
 468         ///
 469         /// [`payer_id`]: Self::payer_id
 470         pub fn signature(&self) -> Signature {
 471                 self.signature
 472         }
 473
 474         /// Creates an [`InvoiceBuilder`] for the request with the given required fields and using the
 475         /// [`Duration`] since [`std::time::SystemTime::UNIX_EPOCH`] as the creation time.
 476         ///
 477         /// See [`InvoiceRequest::respond_with_no_std`] for further details where the aforementioned
 478         /// creation time is used for the `created_at` parameter.
 479         ///
 480         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 481         ///
 482         /// [`Duration`]: core::time::Duration
 483         #[cfg(feature = "std")]
 484         pub fn respond_with(
 485                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash
 486         ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, Bolt12SemanticError> {
 487                 let created_at = std::time::SystemTime::now()
 488                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 489                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 490
 491                 self.respond_with_no_std(payment_paths, payment_hash, created_at)
 492         }
 493
 494         /// Creates an [`InvoiceBuilder`] for the request with the given required fields.
 495         ///
 496         /// Unless [`InvoiceBuilder::relative_expiry`] is set, the invoice will expire two hours after
 497         /// `created_at`, which is used to set [`Bolt12Invoice::created_at`]. Useful for `no-std` builds
 498         /// where [`std::time::SystemTime`] is not available.
 499         ///
 500         /// The caller is expected to remember the preimage of `payment_hash` in order to claim a payment
 501         /// for the invoice.
 502         ///
 503         /// The `payment_paths` parameter is useful for maintaining the payment recipient's privacy. It
 504         /// must contain one or more elements ordered from most-preferred to least-preferred, if there's
 505         /// a preference. Note, however, that any privacy is lost if a public node id was used for
 506         /// [`Offer::signing_pubkey`].
 507         ///
 508         /// Errors if the request contains unknown required features.
 509         ///
 510         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 511         ///
 512         /// [`Bolt12Invoice::created_at`]: crate::offers::invoice::Bolt12Invoice::created_at
 513         pub fn respond_with_no_std(
 514                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 515                 created_at: core::time::Duration
 516         ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, Bolt12SemanticError> {
 517                 if self.features().requires_unknown_bits() {
 518                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 519                 }
 520
 521                 InvoiceBuilder::for_offer(self, payment_paths, created_at, payment_hash)
 522         }
 523
 524         /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
 525         /// derived signing keys from the originating [`Offer`] to sign the [`Bolt12Invoice`]. Must use
 526         /// the same [`ExpandedKey`] as the one used to create the offer.
 527         ///
 528         /// See [`InvoiceRequest::respond_with`] for further details.
 529         ///
 530         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 531         ///
 532         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 533         #[cfg(feature = "std")]
 534         pub fn verify_and_respond_using_derived_keys<T: secp256k1::Signing>(
 535                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 536                 expanded_key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 537         ) -> Result<InvoiceBuilder<DerivedSigningPubkey>, Bolt12SemanticError> {
 538                 let created_at = std::time::SystemTime::now()
 539                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 540                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 541
 542                 self.verify_and_respond_using_derived_keys_no_std(
 543                         payment_paths, payment_hash, created_at, expanded_key, secp_ctx
 544                 )
 545         }
 546
 547         /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
 548         /// derived signing keys from the originating [`Offer`] to sign the [`Bolt12Invoice`]. Must use
 549         /// the same [`ExpandedKey`] as the one used to create the offer.
 550         ///
 551         /// See [`InvoiceRequest::respond_with_no_std`] for further details.
 552         ///
 553         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 554         ///
 555         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 556         pub fn verify_and_respond_using_derived_keys_no_std<T: secp256k1::Signing>(
 557                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 558                 created_at: core::time::Duration, expanded_key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 559         ) -> Result<InvoiceBuilder<DerivedSigningPubkey>, Bolt12SemanticError> {
 560                 if self.features().requires_unknown_bits() {
 561                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 562                 }
 563
 564                 let keys = match self.verify(expanded_key, secp_ctx) {
 565                         Err(()) => return Err(Bolt12SemanticError::InvalidMetadata),
 566                         Ok(None) => return Err(Bolt12SemanticError::InvalidMetadata),
 567                         Ok(Some(keys)) => keys,
 568                 };
 569
 570                 InvoiceBuilder::for_offer_using_keys(self, payment_paths, created_at, payment_hash, keys)
 571         }
 572
 573         /// Verifies that the request was for an offer created using the given key. Returns the derived
 574         /// keys need to sign an [`Bolt12Invoice`] for the request if they could be extracted from the
 575         /// metadata.
 576         ///
 577         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 578         pub fn verify<T: secp256k1::Signing>(
 579                 &self, key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 580         ) -> Result<Option<KeyPair>, ()> {
 581                 self.contents.inner.offer.verify(&self.bytes, key, secp_ctx)
 582         }
 583
 584         #[cfg(test)]
 585         fn as_tlv_stream(&self) -> FullInvoiceRequestTlvStreamRef {
 586                 let (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream) =
 587                         self.contents.as_tlv_stream();
 588                 let signature_tlv_stream = SignatureTlvStreamRef {
 589                         signature: Some(&self.signature),
 590                 };
 591                 (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, signature_tlv_stream)
 592         }
 593 }
 594
 595 impl InvoiceRequestContents {
 596         pub fn metadata(&self) -> &[u8] {
 597                 self.inner.metadata()
 598         }
 599
 600         pub(super) fn derives_keys(&self) -> bool {
 601                 self.inner.payer.0.derives_keys()
 602         }
 603
 604         pub(super) fn chain(&self) -> ChainHash {
 605                 self.inner.chain()
 606         }
 607
 608         pub(super) fn payer_id(&self) -> PublicKey {
 609                 self.payer_id
 610         }
 611
 612         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 613                 let (payer, offer, mut invoice_request) = self.inner.as_tlv_stream();
 614                 invoice_request.payer_id = Some(&self.payer_id);
 615                 (payer, offer, invoice_request)
 616         }
 617 }
 618
 619 impl InvoiceRequestContentsWithoutPayerId {
 620         pub(super) fn metadata(&self) -> &[u8] {
 621                 self.payer.0.as_bytes().map(|bytes| bytes.as_slice()).unwrap_or(&[])
 622         }
 623
 624         pub(super) fn chain(&self) -> ChainHash {
 625                 self.chain.unwrap_or_else(|| self.offer.implied_chain())
 626         }
 627
 628         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 629                 let payer = PayerTlvStreamRef {
 630                         metadata: self.payer.0.as_bytes(),
 631                 };
 632
 633                 let offer = self.offer.as_tlv_stream();
 634
 635                 let features = {
 636                         if self.features == InvoiceRequestFeatures::empty() { None }
 637                         else { Some(&self.features) }
 638                 };
 639
 640                 let invoice_request = InvoiceRequestTlvStreamRef {
 641                         chain: self.chain.as_ref(),
 642                         amount: self.amount_msats,
 643                         features,
 644                         quantity: self.quantity,
 645                         payer_id: None,
 646                         payer_note: self.payer_note.as_ref(),
 647                 };
 648
 649                 (payer, offer, invoice_request)
 650         }
 651 }
 652
 653 impl Writeable for InvoiceRequest {
 654         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 655                 WithoutLength(&self.bytes).write(writer)
 656         }
 657 }
 658
 659 impl Writeable for InvoiceRequestContents {
 660         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 661                 self.as_tlv_stream().write(writer)
 662         }
 663 }
 664
 665 /// Valid type range for invoice_request TLV records.
 666 pub(super) const INVOICE_REQUEST_TYPES: core::ops::Range<u64> = 80..160;
 667
 668 /// TLV record type for [`InvoiceRequest::payer_id`] and [`Refund::payer_id`].
 669 ///
 670 /// [`Refund::payer_id`]: crate::offers::refund::Refund::payer_id
 671 pub(super) const INVOICE_REQUEST_PAYER_ID_TYPE: u64 = 88;
 672
 673 tlv_stream!(InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef, INVOICE_REQUEST_TYPES, {
 674         (80, chain: ChainHash),
 675         (82, amount: (u64, HighZeroBytesDroppedBigSize)),
 676         (84, features: (InvoiceRequestFeatures, WithoutLength)),
 677         (86, quantity: (u64, HighZeroBytesDroppedBigSize)),
 678         (INVOICE_REQUEST_PAYER_ID_TYPE, payer_id: PublicKey),
 679         (89, payer_note: (String, WithoutLength)),
 680 });
 681
 682 type FullInvoiceRequestTlvStream =
 683         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, SignatureTlvStream);
 684
 685 #[cfg(test)]
 686 type FullInvoiceRequestTlvStreamRef<'a> = (
 687         PayerTlvStreamRef<'a>,
 688         OfferTlvStreamRef<'a>,
 689         InvoiceRequestTlvStreamRef<'a>,
 690         SignatureTlvStreamRef<'a>,
 691 );
 692
 693 impl SeekReadable for FullInvoiceRequestTlvStream {
 694         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 695                 let payer = SeekReadable::read(r)?;
 696                 let offer = SeekReadable::read(r)?;
 697                 let invoice_request = SeekReadable::read(r)?;
 698                 let signature = SeekReadable::read(r)?;
 699
 700                 Ok((payer, offer, invoice_request, signature))
 701         }
 702 }
 703
 704 type PartialInvoiceRequestTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
 705
 706 type PartialInvoiceRequestTlvStreamRef<'a> = (
 707         PayerTlvStreamRef<'a>,
 708         OfferTlvStreamRef<'a>,
 709         InvoiceRequestTlvStreamRef<'a>,
 710 );
 711
 712 impl TryFrom<Vec<u8>> for InvoiceRequest {
 713         type Error = Bolt12ParseError;
 714
 715         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 716                 let invoice_request = ParsedMessage::<FullInvoiceRequestTlvStream>::try_from(bytes)?;
 717                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
 718                 let (
 719                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
 720                         SignatureTlvStream { signature },
 721                 ) = tlv_stream;
 722                 let contents = InvoiceRequestContents::try_from(
 723                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 724                 )?;
 725
 726                 let signature = match signature {
 727                         None => return Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
 728                         Some(signature) => signature,
 729                 };
 730                 merkle::verify_signature(&signature, SIGNATURE_TAG, &bytes, contents.payer_id)?;
 731
 732                 Ok(InvoiceRequest { bytes, contents, signature })
 733         }
 734 }
 735
 736 impl TryFrom<PartialInvoiceRequestTlvStream> for InvoiceRequestContents {
 737         type Error = Bolt12SemanticError;
 738
 739         fn try_from(tlv_stream: PartialInvoiceRequestTlvStream) -> Result<Self, Self::Error> {
 740                 let (
 741                         PayerTlvStream { metadata },
 742                         offer_tlv_stream,
 743                         InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
 744                 ) = tlv_stream;
 745
 746                 let payer = match metadata {
 747                         None => return Err(Bolt12SemanticError::MissingPayerMetadata),
 748                         Some(metadata) => PayerContents(Metadata::Bytes(metadata)),
 749                 };
 750                 let offer = OfferContents::try_from(offer_tlv_stream)?;
 751
 752                 if !offer.supports_chain(chain.unwrap_or_else(|| offer.implied_chain())) {
 753                         return Err(Bolt12SemanticError::UnsupportedChain);
 754                 }
 755
 756                 if offer.amount().is_none() && amount.is_none() {
 757                         return Err(Bolt12SemanticError::MissingAmount);
 758                 }
 759
 760                 offer.check_quantity(quantity)?;
 761                 offer.check_amount_msats_for_quantity(amount, quantity)?;
 762
 763                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
 764
 765                 let payer_id = match payer_id {
 766                         None => return Err(Bolt12SemanticError::MissingPayerId),
 767                         Some(payer_id) => payer_id,
 768                 };
 769
 770                 Ok(InvoiceRequestContents {
 771                         inner: InvoiceRequestContentsWithoutPayerId {
 772                                 payer, offer, chain, amount_msats: amount, features, quantity, payer_note,
 773                         },
 774                         payer_id,
 775                 })
 776         }
 777 }
 778
 779 #[cfg(test)]
 780 mod tests {
 781         use super::{InvoiceRequest, InvoiceRequestTlvStreamRef, SIGNATURE_TAG};
 782
 783         use bitcoin::blockdata::constants::ChainHash;
 784         use bitcoin::network::constants::Network;
 785         use bitcoin::secp256k1::{KeyPair, Secp256k1, SecretKey, self};
 786         use core::convert::{Infallible, TryFrom};
 787         use core::num::NonZeroU64;
 788         #[cfg(feature = "std")]
 789         use core::time::Duration;
 790         use crate::sign::KeyMaterial;
 791         use crate::ln::features::InvoiceRequestFeatures;
 792         use crate::ln::inbound_payment::ExpandedKey;
 793         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 794         use crate::offers::invoice::{Bolt12Invoice, SIGNATURE_TAG as INVOICE_SIGNATURE_TAG};
 795         use crate::offers::merkle::{SignError, SignatureTlvStreamRef, self};
 796         use crate::offers::offer::{Amount, OfferBuilder, OfferTlvStreamRef, Quantity};
 797         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
 798         use crate::offers::payer::PayerTlvStreamRef;
 799         use crate::offers::test_utils::*;
 800         use crate::util::ser::{BigSize, Writeable};
 801         use crate::util::string::PrintableString;
 802
 803         #[test]
 804         fn builds_invoice_request_with_defaults() {
 805                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 806                         .amount_msats(1000)
 807                         .build().unwrap()
 808                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 809                         .build().unwrap()
 810                         .sign(payer_sign).unwrap();
 811
 812                 let mut buffer = Vec::new();
 813                 invoice_request.write(&mut buffer).unwrap();
 814
 815                 assert_eq!(invoice_request.bytes, buffer.as_slice());
 816                 assert_eq!(invoice_request.metadata(), &[1; 32]);
 817                 assert_eq!(invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
 818                 assert_eq!(invoice_request.amount_msats(), None);
 819                 assert_eq!(invoice_request.features(), &InvoiceRequestFeatures::empty());
 820                 assert_eq!(invoice_request.quantity(), None);
 821                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
 822                 assert_eq!(invoice_request.payer_note(), None);
 823                 assert!(
 824                         merkle::verify_signature(
 825                                 &invoice_request.signature, SIGNATURE_TAG, &invoice_request.bytes, payer_pubkey()
 826                         ).is_ok()
 827                 );
 828
 829                 assert_eq!(
 830                         invoice_request.as_tlv_stream(),
 831                         (
 832                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
 833                                 OfferTlvStreamRef {
 834                                         chains: None,
 835                                         metadata: None,
 836                                         currency: None,
 837                                         amount: Some(1000),
 838                                         description: Some(&String::from("foo")),
 839                                         features: None,
 840                                         absolute_expiry: None,
 841                                         paths: None,
 842                                         issuer: None,
 843                                         quantity_max: None,
 844                                         node_id: Some(&recipient_pubkey()),
 845                                 },
 846                                 InvoiceRequestTlvStreamRef {
 847                                         chain: None,
 848                                         amount: None,
 849                                         features: None,
 850                                         quantity: None,
 851                                         payer_id: Some(&payer_pubkey()),
 852                                         payer_note: None,
 853                                 },
 854                                 SignatureTlvStreamRef { signature: Some(&invoice_request.signature()) },
 855                         ),
 856                 );
 857
 858                 if let Err(e) = InvoiceRequest::try_from(buffer) {
 859                         panic!("error parsing invoice request: {:?}", e);
 860                 }
 861         }
 862
 863         #[cfg(feature = "std")]
 864         #[test]
 865         fn builds_invoice_request_from_offer_with_expiration() {
 866                 let future_expiry = Duration::from_secs(u64::max_value());
 867                 let past_expiry = Duration::from_secs(0);
 868
 869                 if let Err(e) = OfferBuilder::new("foo".into(), recipient_pubkey())
 870                         .amount_msats(1000)
 871                         .absolute_expiry(future_expiry)
 872                         .build().unwrap()
 873                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 874                         .build()
 875                 {
 876                         panic!("error building invoice_request: {:?}", e);
 877                 }
 878
 879                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 880                         .amount_msats(1000)
 881                         .absolute_expiry(past_expiry)
 882                         .build().unwrap()
 883                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 884                         .build()
 885                 {
 886                         Ok(_) => panic!("expected error"),
 887                         Err(e) => assert_eq!(e, Bolt12SemanticError::AlreadyExpired),
 888                 }
 889         }
 890
 891         #[test]
 892         fn builds_invoice_request_with_derived_metadata() {
 893                 let payer_id = payer_pubkey();
 894                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
 895                 let entropy = FixedEntropy {};
 896                 let secp_ctx = Secp256k1::new();
 897
 898                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
 899                         .amount_msats(1000)
 900                         .build().unwrap();
 901                 let invoice_request = offer
 902                         .request_invoice_deriving_metadata(payer_id, &expanded_key, &entropy)
 903                         .unwrap()
 904                         .build().unwrap()
 905                         .sign(payer_sign).unwrap();
 906                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
 907
 908                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
 909                         .unwrap()
 910                         .build().unwrap()
 911                         .sign(recipient_sign).unwrap();
 912                 assert!(invoice.verify(&expanded_key, &secp_ctx));
 913
 914                 // Fails verification with altered fields
 915                 let (
 916                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
 917                         mut invoice_tlv_stream, mut signature_tlv_stream
 918                 ) = invoice.as_tlv_stream();
 919                 invoice_request_tlv_stream.amount = Some(2000);
 920                 invoice_tlv_stream.amount = Some(2000);
 921
 922                 let tlv_stream =
 923                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
 924                 let mut bytes = Vec::new();
 925                 tlv_stream.write(&mut bytes).unwrap();
 926
 927                 let signature = merkle::sign_message(
 928                         recipient_sign, INVOICE_SIGNATURE_TAG, &bytes, recipient_pubkey()
 929                 ).unwrap();
 930                 signature_tlv_stream.signature = Some(&signature);
 931
 932                 let mut encoded_invoice = bytes;
 933                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
 934
 935                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
 936                 assert!(!invoice.verify(&expanded_key, &secp_ctx));
 937
 938                 // Fails verification with altered metadata
 939                 let (
 940                         mut payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
 941                         mut signature_tlv_stream
 942                 ) = invoice.as_tlv_stream();
 943                 let metadata = payer_tlv_stream.metadata.unwrap().iter().copied().rev().collect();
 944                 payer_tlv_stream.metadata = Some(&metadata);
 945
 946                 let tlv_stream =
 947                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
 948                 let mut bytes = Vec::new();
 949                 tlv_stream.write(&mut bytes).unwrap();
 950
 951                 let signature = merkle::sign_message(
 952                         recipient_sign, INVOICE_SIGNATURE_TAG, &bytes, recipient_pubkey()
 953                 ).unwrap();
 954                 signature_tlv_stream.signature = Some(&signature);
 955
 956                 let mut encoded_invoice = bytes;
 957                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
 958
 959                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
 960                 assert!(!invoice.verify(&expanded_key, &secp_ctx));
 961         }
 962
 963         #[test]
 964         fn builds_invoice_request_with_derived_payer_id() {
 965                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
 966                 let entropy = FixedEntropy {};
 967                 let secp_ctx = Secp256k1::new();
 968
 969                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
 970                         .amount_msats(1000)
 971                         .build().unwrap();
 972                 let invoice_request = offer
 973                         .request_invoice_deriving_payer_id(&expanded_key, &entropy, &secp_ctx)
 974                         .unwrap()
 975                         .build_and_sign()
 976                         .unwrap();
 977
 978                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
 979                         .unwrap()
 980                         .build().unwrap()
 981                         .sign(recipient_sign).unwrap();
 982                 assert!(invoice.verify(&expanded_key, &secp_ctx));
 983
 984                 // Fails verification with altered fields
 985                 let (
 986                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
 987                         mut invoice_tlv_stream, mut signature_tlv_stream
 988                 ) = invoice.as_tlv_stream();
 989                 invoice_request_tlv_stream.amount = Some(2000);
 990                 invoice_tlv_stream.amount = Some(2000);
 991
 992                 let tlv_stream =
 993                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
 994                 let mut bytes = Vec::new();
 995                 tlv_stream.write(&mut bytes).unwrap();
 996
 997                 let signature = merkle::sign_message(
 998                         recipient_sign, INVOICE_SIGNATURE_TAG, &bytes, recipient_pubkey()
 999                 ).unwrap();
1000                 signature_tlv_stream.signature = Some(&signature);
1001
1002                 let mut encoded_invoice = bytes;
1003                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1004
1005                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1006                 assert!(!invoice.verify(&expanded_key, &secp_ctx));
1007
1008                 // Fails verification with altered payer id
1009                 let (
1010                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream, invoice_tlv_stream,
1011                         mut signature_tlv_stream
1012                 ) = invoice.as_tlv_stream();
1013                 let payer_id = pubkey(1);
1014                 invoice_request_tlv_stream.payer_id = Some(&payer_id);
1015
1016                 let tlv_stream =
1017                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1018                 let mut bytes = Vec::new();
1019                 tlv_stream.write(&mut bytes).unwrap();
1020
1021                 let signature = merkle::sign_message(
1022                         recipient_sign, INVOICE_SIGNATURE_TAG, &bytes, recipient_pubkey()
1023                 ).unwrap();
1024                 signature_tlv_stream.signature = Some(&signature);
1025
1026                 let mut encoded_invoice = bytes;
1027                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1028
1029                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1030                 assert!(!invoice.verify(&expanded_key, &secp_ctx));
1031         }
1032
1033         #[test]
1034         fn builds_invoice_request_with_chain() {
1035                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
1036                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
1037
1038                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1039                         .amount_msats(1000)
1040                         .build().unwrap()
1041                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1042                         .chain(Network::Bitcoin).unwrap()
1043                         .build().unwrap()
1044                         .sign(payer_sign).unwrap();
1045                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1046                 assert_eq!(invoice_request.chain(), mainnet);
1047                 assert_eq!(tlv_stream.chain, None);
1048
1049                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1050                         .amount_msats(1000)
1051                         .chain(Network::Testnet)
1052                         .build().unwrap()
1053                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1054                         .chain(Network::Testnet).unwrap()
1055                         .build().unwrap()
1056                         .sign(payer_sign).unwrap();
1057                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1058                 assert_eq!(invoice_request.chain(), testnet);
1059                 assert_eq!(tlv_stream.chain, Some(&testnet));
1060
1061                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1062                         .amount_msats(1000)
1063                         .chain(Network::Bitcoin)
1064                         .chain(Network::Testnet)
1065                         .build().unwrap()
1066                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1067                         .chain(Network::Bitcoin).unwrap()
1068                         .build().unwrap()
1069                         .sign(payer_sign).unwrap();
1070                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1071                 assert_eq!(invoice_request.chain(), mainnet);
1072                 assert_eq!(tlv_stream.chain, None);
1073
1074                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1075                         .amount_msats(1000)
1076                         .chain(Network::Bitcoin)
1077                         .chain(Network::Testnet)
1078                         .build().unwrap()
1079                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1080                         .chain(Network::Bitcoin).unwrap()
1081                         .chain(Network::Testnet).unwrap()
1082                         .build().unwrap()
1083                         .sign(payer_sign).unwrap();
1084                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1085                 assert_eq!(invoice_request.chain(), testnet);
1086                 assert_eq!(tlv_stream.chain, Some(&testnet));
1087
1088                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1089                         .amount_msats(1000)
1090                         .chain(Network::Testnet)
1091                         .build().unwrap()
1092                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1093                         .chain(Network::Bitcoin)
1094                 {
1095                         Ok(_) => panic!("expected error"),
1096                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
1097                 }
1098
1099                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1100                         .amount_msats(1000)
1101                         .chain(Network::Testnet)
1102                         .build().unwrap()
1103                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1104                         .build()
1105                 {
1106                         Ok(_) => panic!("expected error"),
1107                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
1108                 }
1109         }
1110
1111         #[test]
1112         fn builds_invoice_request_with_amount() {
1113                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1114                         .amount_msats(1000)
1115                         .build().unwrap()
1116                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1117                         .amount_msats(1000).unwrap()
1118                         .build().unwrap()
1119                         .sign(payer_sign).unwrap();
1120                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1121                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1122                 assert_eq!(tlv_stream.amount, Some(1000));
1123
1124                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1125                         .amount_msats(1000)
1126                         .build().unwrap()
1127                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1128                         .amount_msats(1001).unwrap()
1129                         .amount_msats(1000).unwrap()
1130                         .build().unwrap()
1131                         .sign(payer_sign).unwrap();
1132                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1133                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1134                 assert_eq!(tlv_stream.amount, Some(1000));
1135
1136                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1137                         .amount_msats(1000)
1138                         .build().unwrap()
1139                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1140                         .amount_msats(1001).unwrap()
1141                         .build().unwrap()
1142                         .sign(payer_sign).unwrap();
1143                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1144                 assert_eq!(invoice_request.amount_msats(), Some(1001));
1145                 assert_eq!(tlv_stream.amount, Some(1001));
1146
1147                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1148                         .amount_msats(1000)
1149                         .build().unwrap()
1150                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1151                         .amount_msats(999)
1152                 {
1153                         Ok(_) => panic!("expected error"),
1154                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1155                 }
1156
1157                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1158                         .amount_msats(1000)
1159                         .supported_quantity(Quantity::Unbounded)
1160                         .build().unwrap()
1161                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1162                         .quantity(2).unwrap()
1163                         .amount_msats(1000)
1164                 {
1165                         Ok(_) => panic!("expected error"),
1166                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1167                 }
1168
1169                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1170                         .amount_msats(1000)
1171                         .build().unwrap()
1172                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1173                         .amount_msats(MAX_VALUE_MSAT + 1)
1174                 {
1175                         Ok(_) => panic!("expected error"),
1176                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1177                 }
1178
1179                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1180                         .amount_msats(1000)
1181                         .supported_quantity(Quantity::Unbounded)
1182                         .build().unwrap()
1183                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1184                         .amount_msats(1000).unwrap()
1185                         .quantity(2).unwrap()
1186                         .build()
1187                 {
1188                         Ok(_) => panic!("expected error"),
1189                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1190                 }
1191
1192                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1193                         .build().unwrap()
1194                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1195                         .build()
1196                 {
1197                         Ok(_) => panic!("expected error"),
1198                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingAmount),
1199                 }
1200
1201                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1202                         .amount_msats(1000)
1203                         .supported_quantity(Quantity::Unbounded)
1204                         .build().unwrap()
1205                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1206                         .quantity(u64::max_value()).unwrap()
1207                         .build()
1208                 {
1209                         Ok(_) => panic!("expected error"),
1210                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1211                 }
1212         }
1213
1214         #[test]
1215         fn builds_invoice_request_with_features() {
1216                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1217                         .amount_msats(1000)
1218                         .build().unwrap()
1219                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1220                         .features_unchecked(InvoiceRequestFeatures::unknown())
1221                         .build().unwrap()
1222                         .sign(payer_sign).unwrap();
1223                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1224                 assert_eq!(invoice_request.features(), &InvoiceRequestFeatures::unknown());
1225                 assert_eq!(tlv_stream.features, Some(&InvoiceRequestFeatures::unknown()));
1226
1227                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1228                         .amount_msats(1000)
1229                         .build().unwrap()
1230                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1231                         .features_unchecked(InvoiceRequestFeatures::unknown())
1232                         .features_unchecked(InvoiceRequestFeatures::empty())
1233                         .build().unwrap()
1234                         .sign(payer_sign).unwrap();
1235                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1236                 assert_eq!(invoice_request.features(), &InvoiceRequestFeatures::empty());
1237                 assert_eq!(tlv_stream.features, None);
1238         }
1239
1240         #[test]
1241         fn builds_invoice_request_with_quantity() {
1242                 let one = NonZeroU64::new(1).unwrap();
1243                 let ten = NonZeroU64::new(10).unwrap();
1244
1245                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1246                         .amount_msats(1000)
1247                         .supported_quantity(Quantity::One)
1248                         .build().unwrap()
1249                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1250                         .build().unwrap()
1251                         .sign(payer_sign).unwrap();
1252                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1253                 assert_eq!(invoice_request.quantity(), None);
1254                 assert_eq!(tlv_stream.quantity, None);
1255
1256                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1257                         .amount_msats(1000)
1258                         .supported_quantity(Quantity::One)
1259                         .build().unwrap()
1260                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1261                         .amount_msats(2_000).unwrap()
1262                         .quantity(2)
1263                 {
1264                         Ok(_) => panic!("expected error"),
1265                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnexpectedQuantity),
1266                 }
1267
1268                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1269                         .amount_msats(1000)
1270                         .supported_quantity(Quantity::Bounded(ten))
1271                         .build().unwrap()
1272                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1273                         .amount_msats(10_000).unwrap()
1274                         .quantity(10).unwrap()
1275                         .build().unwrap()
1276                         .sign(payer_sign).unwrap();
1277                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1278                 assert_eq!(invoice_request.amount_msats(), Some(10_000));
1279                 assert_eq!(tlv_stream.amount, Some(10_000));
1280
1281                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1282                         .amount_msats(1000)
1283                         .supported_quantity(Quantity::Bounded(ten))
1284                         .build().unwrap()
1285                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1286                         .amount_msats(11_000).unwrap()
1287                         .quantity(11)
1288                 {
1289                         Ok(_) => panic!("expected error"),
1290                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidQuantity),
1291                 }
1292
1293                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1294                         .amount_msats(1000)
1295                         .supported_quantity(Quantity::Unbounded)
1296                         .build().unwrap()
1297                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1298                         .amount_msats(2_000).unwrap()
1299                         .quantity(2).unwrap()
1300                         .build().unwrap()
1301                         .sign(payer_sign).unwrap();
1302                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1303                 assert_eq!(invoice_request.amount_msats(), Some(2_000));
1304                 assert_eq!(tlv_stream.amount, Some(2_000));
1305
1306                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1307                         .amount_msats(1000)
1308                         .supported_quantity(Quantity::Unbounded)
1309                         .build().unwrap()
1310                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1311                         .build()
1312                 {
1313                         Ok(_) => panic!("expected error"),
1314                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
1315                 }
1316
1317                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1318                         .amount_msats(1000)
1319                         .supported_quantity(Quantity::Bounded(one))
1320                         .build().unwrap()
1321                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1322                         .build()
1323                 {
1324                         Ok(_) => panic!("expected error"),
1325                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
1326                 }
1327         }
1328
1329         #[test]
1330         fn builds_invoice_request_with_payer_note() {
1331                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1332                         .amount_msats(1000)
1333                         .build().unwrap()
1334                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1335                         .payer_note("bar".into())
1336                         .build().unwrap()
1337                         .sign(payer_sign).unwrap();
1338                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1339                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("bar")));
1340                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
1341
1342                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1343                         .amount_msats(1000)
1344                         .build().unwrap()
1345                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1346                         .payer_note("bar".into())
1347                         .payer_note("baz".into())
1348                         .build().unwrap()
1349                         .sign(payer_sign).unwrap();
1350                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1351                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("baz")));
1352                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
1353         }
1354
1355         #[test]
1356         fn fails_signing_invoice_request() {
1357                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1358                         .amount_msats(1000)
1359                         .build().unwrap()
1360                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1361                         .build().unwrap()
1362                         .sign(|_| Err(()))
1363                 {
1364                         Ok(_) => panic!("expected error"),
1365                         Err(e) => assert_eq!(e, SignError::Signing(())),
1366                 }
1367
1368                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1369                         .amount_msats(1000)
1370                         .build().unwrap()
1371                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1372                         .build().unwrap()
1373                         .sign(recipient_sign)
1374                 {
1375                         Ok(_) => panic!("expected error"),
1376                         Err(e) => assert_eq!(e, SignError::Verification(secp256k1::Error::InvalidSignature)),
1377                 }
1378         }
1379
1380         #[test]
1381         fn fails_responding_with_unknown_required_features() {
1382                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1383                         .amount_msats(1000)
1384                         .build().unwrap()
1385                         .request_invoice(vec![42; 32], payer_pubkey()).unwrap()
1386                         .features_unchecked(InvoiceRequestFeatures::unknown())
1387                         .build().unwrap()
1388                         .sign(payer_sign).unwrap()
1389                         .respond_with_no_std(payment_paths(), payment_hash(), now())
1390                 {
1391                         Ok(_) => panic!("expected error"),
1392                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1393                 }
1394         }
1395
1396         #[test]
1397         fn parses_invoice_request_with_metadata() {
1398                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1399                         .amount_msats(1000)
1400                         .build().unwrap()
1401                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1402                         .build().unwrap()
1403                         .sign(payer_sign).unwrap();
1404
1405                 let mut buffer = Vec::new();
1406                 invoice_request.write(&mut buffer).unwrap();
1407
1408                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1409                         panic!("error parsing invoice_request: {:?}", e);
1410                 }
1411         }
1412
1413         #[test]
1414         fn parses_invoice_request_with_chain() {
1415                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1416                         .amount_msats(1000)
1417                         .build().unwrap()
1418                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1419                         .chain(Network::Bitcoin).unwrap()
1420                         .build().unwrap()
1421                         .sign(payer_sign).unwrap();
1422
1423                 let mut buffer = Vec::new();
1424                 invoice_request.write(&mut buffer).unwrap();
1425
1426                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1427                         panic!("error parsing invoice_request: {:?}", e);
1428                 }
1429
1430                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1431                         .amount_msats(1000)
1432                         .build().unwrap()
1433                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1434                         .chain_unchecked(Network::Testnet)
1435                         .build_unchecked()
1436                         .sign(payer_sign).unwrap();
1437
1438                 let mut buffer = Vec::new();
1439                 invoice_request.write(&mut buffer).unwrap();
1440
1441                 match InvoiceRequest::try_from(buffer) {
1442                         Ok(_) => panic!("expected error"),
1443                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnsupportedChain)),
1444                 }
1445         }
1446
1447         #[test]
1448         fn parses_invoice_request_with_amount() {
1449                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1450                         .amount_msats(1000)
1451                         .build().unwrap()
1452                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1453                         .build().unwrap()
1454                         .sign(payer_sign).unwrap();
1455
1456                 let mut buffer = Vec::new();
1457                 invoice_request.write(&mut buffer).unwrap();
1458
1459                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1460                         panic!("error parsing invoice_request: {:?}", e);
1461                 }
1462
1463                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1464                         .build().unwrap()
1465                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1466                         .amount_msats(1000).unwrap()
1467                         .build().unwrap()
1468                         .sign(payer_sign).unwrap();
1469
1470                 let mut buffer = Vec::new();
1471                 invoice_request.write(&mut buffer).unwrap();
1472
1473                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1474                         panic!("error parsing invoice_request: {:?}", e);
1475                 }
1476
1477                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1478                         .build().unwrap()
1479                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1480                         .build_unchecked()
1481                         .sign(payer_sign).unwrap();
1482
1483                 let mut buffer = Vec::new();
1484                 invoice_request.write(&mut buffer).unwrap();
1485
1486                 match InvoiceRequest::try_from(buffer) {
1487                         Ok(_) => panic!("expected error"),
1488                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1489                 }
1490
1491                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1492                         .amount_msats(1000)
1493                         .build().unwrap()
1494                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1495                         .amount_msats_unchecked(999)
1496                         .build_unchecked()
1497                         .sign(payer_sign).unwrap();
1498
1499                 let mut buffer = Vec::new();
1500                 invoice_request.write(&mut buffer).unwrap();
1501
1502                 match InvoiceRequest::try_from(buffer) {
1503                         Ok(_) => panic!("expected error"),
1504                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InsufficientAmount)),
1505                 }
1506
1507                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1508                         .amount(Amount::Currency { iso4217_code: *b"USD", amount: 1000 })
1509                         .build_unchecked()
1510                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1511                         .build_unchecked()
1512                         .sign(payer_sign).unwrap();
1513
1514                 let mut buffer = Vec::new();
1515                 invoice_request.write(&mut buffer).unwrap();
1516
1517                 match InvoiceRequest::try_from(buffer) {
1518                         Ok(_) => panic!("expected error"),
1519                         Err(e) => {
1520                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnsupportedCurrency));
1521                         },
1522                 }
1523
1524                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1525                         .amount_msats(1000)
1526                         .supported_quantity(Quantity::Unbounded)
1527                         .build().unwrap()
1528                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1529                         .quantity(u64::max_value()).unwrap()
1530                         .build_unchecked()
1531                         .sign(payer_sign).unwrap();
1532
1533                 let mut buffer = Vec::new();
1534                 invoice_request.write(&mut buffer).unwrap();
1535
1536                 match InvoiceRequest::try_from(buffer) {
1537                         Ok(_) => panic!("expected error"),
1538                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1539                 }
1540         }
1541
1542         #[test]
1543         fn parses_invoice_request_with_quantity() {
1544                 let one = NonZeroU64::new(1).unwrap();
1545                 let ten = NonZeroU64::new(10).unwrap();
1546
1547                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1548                         .amount_msats(1000)
1549                         .supported_quantity(Quantity::One)
1550                         .build().unwrap()
1551                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1552                         .build().unwrap()
1553                         .sign(payer_sign).unwrap();
1554
1555                 let mut buffer = Vec::new();
1556                 invoice_request.write(&mut buffer).unwrap();
1557
1558                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1559                         panic!("error parsing invoice_request: {:?}", e);
1560                 }
1561
1562                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1563                         .amount_msats(1000)
1564                         .supported_quantity(Quantity::One)
1565                         .build().unwrap()
1566                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1567                         .amount_msats(2_000).unwrap()
1568                         .quantity_unchecked(2)
1569                         .build_unchecked()
1570                         .sign(payer_sign).unwrap();
1571
1572                 let mut buffer = Vec::new();
1573                 invoice_request.write(&mut buffer).unwrap();
1574
1575                 match InvoiceRequest::try_from(buffer) {
1576                         Ok(_) => panic!("expected error"),
1577                         Err(e) => {
1578                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnexpectedQuantity));
1579                         },
1580                 }
1581
1582                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1583                         .amount_msats(1000)
1584                         .supported_quantity(Quantity::Bounded(ten))
1585                         .build().unwrap()
1586                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1587                         .amount_msats(10_000).unwrap()
1588                         .quantity(10).unwrap()
1589                         .build().unwrap()
1590                         .sign(payer_sign).unwrap();
1591
1592                 let mut buffer = Vec::new();
1593                 invoice_request.write(&mut buffer).unwrap();
1594
1595                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1596                         panic!("error parsing invoice_request: {:?}", e);
1597                 }
1598
1599                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1600                         .amount_msats(1000)
1601                         .supported_quantity(Quantity::Bounded(ten))
1602                         .build().unwrap()
1603                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1604                         .amount_msats(11_000).unwrap()
1605                         .quantity_unchecked(11)
1606                         .build_unchecked()
1607                         .sign(payer_sign).unwrap();
1608
1609                 let mut buffer = Vec::new();
1610                 invoice_request.write(&mut buffer).unwrap();
1611
1612                 match InvoiceRequest::try_from(buffer) {
1613                         Ok(_) => panic!("expected error"),
1614                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidQuantity)),
1615                 }
1616
1617                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1618                         .amount_msats(1000)
1619                         .supported_quantity(Quantity::Unbounded)
1620                         .build().unwrap()
1621                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1622                         .amount_msats(2_000).unwrap()
1623                         .quantity(2).unwrap()
1624                         .build().unwrap()
1625                         .sign(payer_sign).unwrap();
1626
1627                 let mut buffer = Vec::new();
1628                 invoice_request.write(&mut buffer).unwrap();
1629
1630                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1631                         panic!("error parsing invoice_request: {:?}", e);
1632                 }
1633
1634                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1635                         .amount_msats(1000)
1636                         .supported_quantity(Quantity::Unbounded)
1637                         .build().unwrap()
1638                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1639                         .build_unchecked()
1640                         .sign(payer_sign).unwrap();
1641
1642                 let mut buffer = Vec::new();
1643                 invoice_request.write(&mut buffer).unwrap();
1644
1645                 match InvoiceRequest::try_from(buffer) {
1646                         Ok(_) => panic!("expected error"),
1647                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
1648                 }
1649
1650                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1651                         .amount_msats(1000)
1652                         .supported_quantity(Quantity::Bounded(one))
1653                         .build().unwrap()
1654                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1655                         .build_unchecked()
1656                         .sign(payer_sign).unwrap();
1657
1658                 let mut buffer = Vec::new();
1659                 invoice_request.write(&mut buffer).unwrap();
1660
1661                 match InvoiceRequest::try_from(buffer) {
1662                         Ok(_) => panic!("expected error"),
1663                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
1664                 }
1665         }
1666
1667         #[test]
1668         fn fails_parsing_invoice_request_without_metadata() {
1669                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1670                         .amount_msats(1000)
1671                         .build().unwrap();
1672                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1673                         .build().unwrap();
1674                 let mut tlv_stream = unsigned_invoice_request.invoice_request.as_tlv_stream();
1675                 tlv_stream.0.metadata = None;
1676
1677                 let mut buffer = Vec::new();
1678                 tlv_stream.write(&mut buffer).unwrap();
1679
1680                 match InvoiceRequest::try_from(buffer) {
1681                         Ok(_) => panic!("expected error"),
1682                         Err(e) => {
1683                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPayerMetadata));
1684                         },
1685                 }
1686         }
1687
1688         #[test]
1689         fn fails_parsing_invoice_request_without_payer_id() {
1690                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1691                         .amount_msats(1000)
1692                         .build().unwrap();
1693                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1694                         .build().unwrap();
1695                 let mut tlv_stream = unsigned_invoice_request.invoice_request.as_tlv_stream();
1696                 tlv_stream.2.payer_id = None;
1697
1698                 let mut buffer = Vec::new();
1699                 tlv_stream.write(&mut buffer).unwrap();
1700
1701                 match InvoiceRequest::try_from(buffer) {
1702                         Ok(_) => panic!("expected error"),
1703                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPayerId)),
1704                 }
1705         }
1706
1707         #[test]
1708         fn fails_parsing_invoice_request_without_node_id() {
1709                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1710                         .amount_msats(1000)
1711                         .build().unwrap();
1712                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1713                         .build().unwrap();
1714                 let mut tlv_stream = unsigned_invoice_request.invoice_request.as_tlv_stream();
1715                 tlv_stream.1.node_id = None;
1716
1717                 let mut buffer = Vec::new();
1718                 tlv_stream.write(&mut buffer).unwrap();
1719
1720                 match InvoiceRequest::try_from(buffer) {
1721                         Ok(_) => panic!("expected error"),
1722                         Err(e) => {
1723                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1724                         },
1725                 }
1726         }
1727
1728         #[test]
1729         fn fails_parsing_invoice_request_without_signature() {
1730                 let mut buffer = Vec::new();
1731                 OfferBuilder::new("foo".into(), recipient_pubkey())
1732                         .amount_msats(1000)
1733                         .build().unwrap()
1734                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1735                         .build().unwrap()
1736                         .invoice_request
1737                         .write(&mut buffer).unwrap();
1738
1739                 match InvoiceRequest::try_from(buffer) {
1740                         Ok(_) => panic!("expected error"),
1741                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
1742                 }
1743         }
1744
1745         #[test]
1746         fn fails_parsing_invoice_request_with_invalid_signature() {
1747                 let mut invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1748                         .amount_msats(1000)
1749                         .build().unwrap()
1750                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1751                         .build().unwrap()
1752                         .sign(payer_sign).unwrap();
1753                 let last_signature_byte = invoice_request.bytes.last_mut().unwrap();
1754                 *last_signature_byte = last_signature_byte.wrapping_add(1);
1755
1756                 let mut buffer = Vec::new();
1757                 invoice_request.write(&mut buffer).unwrap();
1758
1759                 match InvoiceRequest::try_from(buffer) {
1760                         Ok(_) => panic!("expected error"),
1761                         Err(e) => {
1762                                 assert_eq!(e, Bolt12ParseError::InvalidSignature(secp256k1::Error::InvalidSignature));
1763                         },
1764                 }
1765         }
1766
1767         #[test]
1768         fn fails_parsing_invoice_request_with_extra_tlv_records() {
1769                 let secp_ctx = Secp256k1::new();
1770                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1771                 let invoice_request = OfferBuilder::new("foo".into(), keys.public_key())
1772                         .amount_msats(1000)
1773                         .build().unwrap()
1774                         .request_invoice(vec![1; 32], keys.public_key()).unwrap()
1775                         .build().unwrap()
1776                         .sign::<_, Infallible>(|digest| Ok(secp_ctx.sign_schnorr_no_aux_rand(digest, &keys)))
1777                         .unwrap();
1778
1779                 let mut encoded_invoice_request = Vec::new();
1780                 invoice_request.write(&mut encoded_invoice_request).unwrap();
1781                 BigSize(1002).write(&mut encoded_invoice_request).unwrap();
1782                 BigSize(32).write(&mut encoded_invoice_request).unwrap();
1783                 [42u8; 32].write(&mut encoded_invoice_request).unwrap();
1784
1785                 match InvoiceRequest::try_from(encoded_invoice_request) {
1786                         Ok(_) => panic!("expected error"),
1787                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1788                 }
1789         }
1790 }