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