git.bitcoin.ninja 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::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::{ParseError, ParsedMessage, SemanticError};
  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, SemanticError> {
 175                 let chain = ChainHash::using_genesis_block(network);
 176                 if !self.offer.supports_chain(chain) {
 177                         return Err(SemanticError::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, SemanticError> {
 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, SemanticError> {
 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                 SemanticError
 219         > {
 220                 #[cfg(feature = "std")] {
 221                         if self.offer.is_expired() {
 222                                 return Err(SemanticError::AlreadyExpired);
 223                         }
 224                 }
 225
 226                 let chain = self.invoice_request.chain();
 227                 if !self.offer.supports_chain(chain) {
 228                         return Err(SemanticError::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(SemanticError::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 an Invoice.
 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>, SemanticError> {
 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, SemanticError> {
 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 an [`Invoice`] 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 /// [`Invoice`]: crate::offers::invoice::Invoice
 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 [`Invoice`].
 400 ///
 401 /// [`Invoice`]: crate::offers::invoice::Invoice
 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         /// [`payer_id`]: Self::payer_id
 468         pub fn signature(&self) -> Signature {
 469                 self.signature
 470         }
 471
 472         /// Creates an [`InvoiceBuilder`] for the request with the given required fields and using the
 473         /// [`Duration`] since [`std::time::SystemTime::UNIX_EPOCH`] as the creation time.
 474         ///
 475         /// See [`InvoiceRequest::respond_with_no_std`] for further details where the aforementioned
 476         /// creation time is used for the `created_at` parameter.
 477         ///
 478         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 479         ///
 480         /// [`Duration`]: core::time::Duration
 481         #[cfg(feature = "std")]
 482         pub fn respond_with(
 483                 &self, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>, payment_hash: PaymentHash
 484         ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, SemanticError> {
 485                 let created_at = std::time::SystemTime::now()
 486                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 487                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 488
 489                 self.respond_with_no_std(payment_paths, payment_hash, created_at)
 490         }
 491
 492         /// Creates an [`InvoiceBuilder`] for the request with the given required fields.
 493         ///
 494         /// Unless [`InvoiceBuilder::relative_expiry`] is set, the invoice will expire two hours after
 495         /// `created_at`, which is used to set [`Invoice::created_at`]. Useful for `no-std` builds where
 496         /// [`std::time::SystemTime`] is not available.
 497         ///
 498         /// The caller is expected to remember the preimage of `payment_hash` in order to claim a payment
 499         /// for the invoice.
 500         ///
 501         /// The `payment_paths` parameter is useful for maintaining the payment recipient's privacy. It
 502         /// must contain one or more elements ordered from most-preferred to least-preferred, if there's
 503         /// a preference. Note, however, that any privacy is lost if a public node id was used for
 504         /// [`Offer::signing_pubkey`].
 505         ///
 506         /// Errors if the request contains unknown required features.
 507         ///
 508         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 509         ///
 510         /// [`Invoice::created_at`]: crate::offers::invoice::Invoice::created_at
 511         pub fn respond_with_no_std(
 512                 &self, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>, payment_hash: PaymentHash,
 513                 created_at: core::time::Duration
 514         ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, SemanticError> {
 515                 if self.features().requires_unknown_bits() {
 516                         return Err(SemanticError::UnknownRequiredFeatures);
 517                 }
 518
 519                 InvoiceBuilder::for_offer(self, payment_paths, created_at, payment_hash)
 520         }
 521
 522         /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
 523         /// derived signing keys from the originating [`Offer`] to sign the [`Invoice`]. Must use the
 524         /// same [`ExpandedKey`] as the one used to create the offer.
 525         ///
 526         /// See [`InvoiceRequest::respond_with`] for further details.
 527         ///
 528         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 529         ///
 530         /// [`Invoice`]: crate::offers::invoice::Invoice
 531         #[cfg(feature = "std")]
 532         pub fn verify_and_respond_using_derived_keys<T: secp256k1::Signing>(
 533                 &self, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>, payment_hash: PaymentHash,
 534                 expanded_key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 535         ) -> Result<InvoiceBuilder<DerivedSigningPubkey>, SemanticError> {
 536                 let created_at = std::time::SystemTime::now()
 537                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 538                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 539
 540                 self.verify_and_respond_using_derived_keys_no_std(
 541                         payment_paths, payment_hash, created_at, expanded_key, secp_ctx
 542                 )
 543         }
 544
 545         /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
 546         /// derived signing keys from the originating [`Offer`] to sign the [`Invoice`]. Must use the
 547         /// same [`ExpandedKey`] as the one used to create the offer.
 548         ///
 549         /// See [`InvoiceRequest::respond_with_no_std`] for further details.
 550         ///
 551         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 552         ///
 553         /// [`Invoice`]: crate::offers::invoice::Invoice
 554         pub fn verify_and_respond_using_derived_keys_no_std<T: secp256k1::Signing>(
 555                 &self, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>, payment_hash: PaymentHash,
 556                 created_at: core::time::Duration, expanded_key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 557         ) -> Result<InvoiceBuilder<DerivedSigningPubkey>, SemanticError> {
 558                 if self.features().requires_unknown_bits() {
 559                         return Err(SemanticError::UnknownRequiredFeatures);
 560                 }
 561
 562                 let keys = match self.verify(expanded_key, secp_ctx) {
 563                         Err(()) => return Err(SemanticError::InvalidMetadata),
 564                         Ok(None) => return Err(SemanticError::InvalidMetadata),
 565                         Ok(Some(keys)) => keys,
 566                 };
 567
 568                 InvoiceBuilder::for_offer_using_keys(self, payment_paths, created_at, payment_hash, keys)
 569         }
 570
 571         /// Verifies that the request was for an offer created using the given key. Returns the derived
 572         /// keys need to sign an [`Invoice`] for the request if they could be extracted from the
 573         /// metadata.
 574         ///
 575         /// [`Invoice`]: crate::offers::invoice::Invoice
 576         pub fn verify<T: secp256k1::Signing>(
 577                 &self, key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 578         ) -> Result<Option<KeyPair>, ()> {
 579                 self.contents.inner.offer.verify(&self.bytes, key, secp_ctx)
 580         }
 581
 582         #[cfg(test)]
 583         fn as_tlv_stream(&self) -> FullInvoiceRequestTlvStreamRef {
 584                 let (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream) =
 585                         self.contents.as_tlv_stream();
 586                 let signature_tlv_stream = SignatureTlvStreamRef {
 587                         signature: Some(&self.signature),
 588                 };
 589                 (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, signature_tlv_stream)
 590         }
 591 }
 592
 593 impl InvoiceRequestContents {
 594         pub fn metadata(&self) -> &[u8] {
 595                 self.inner.metadata()
 596         }
 597
 598         pub(super) fn derives_keys(&self) -> bool {
 599                 self.inner.payer.0.derives_keys()
 600         }
 601
 602         pub(super) fn chain(&self) -> ChainHash {
 603                 self.inner.chain()
 604         }
 605
 606         pub(super) fn payer_id(&self) -> PublicKey {
 607                 self.payer_id
 608         }
 609
 610         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 611                 let (payer, offer, mut invoice_request) = self.inner.as_tlv_stream();
 612                 invoice_request.payer_id = Some(&self.payer_id);
 613                 (payer, offer, invoice_request)
 614         }
 615 }
 616
 617 impl InvoiceRequestContentsWithoutPayerId {
 618         pub(super) fn metadata(&self) -> &[u8] {
 619                 self.payer.0.as_bytes().map(|bytes| bytes.as_slice()).unwrap_or(&[])
 620         }
 621
 622         pub(super) fn chain(&self) -> ChainHash {
 623                 self.chain.unwrap_or_else(|| self.offer.implied_chain())
 624         }
 625
 626         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 627                 let payer = PayerTlvStreamRef {
 628                         metadata: self.payer.0.as_bytes(),
 629                 };
 630
 631                 let offer = self.offer.as_tlv_stream();
 632
 633                 let features = {
 634                         if self.features == InvoiceRequestFeatures::empty() { None }
 635                         else { Some(&self.features) }
 636                 };
 637
 638                 let invoice_request = InvoiceRequestTlvStreamRef {
 639                         chain: self.chain.as_ref(),
 640                         amount: self.amount_msats,
 641                         features,
 642                         quantity: self.quantity,
 643                         payer_id: None,
 644                         payer_note: self.payer_note.as_ref(),
 645                 };
 646
 647                 (payer, offer, invoice_request)
 648         }
 649 }
 650
 651 impl Writeable for InvoiceRequest {
 652         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 653                 WithoutLength(&self.bytes).write(writer)
 654         }
 655 }
 656
 657 impl Writeable for InvoiceRequestContents {
 658         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 659                 self.as_tlv_stream().write(writer)
 660         }
 661 }
 662
 663 /// Valid type range for invoice_request TLV records.
 664 pub(super) const INVOICE_REQUEST_TYPES: core::ops::Range<u64> = 80..160;
 665
 666 /// TLV record type for [`InvoiceRequest::payer_id`] and [`Refund::payer_id`].
 667 ///
 668 /// [`Refund::payer_id`]: crate::offers::refund::Refund::payer_id
 669 pub(super) const INVOICE_REQUEST_PAYER_ID_TYPE: u64 = 88;
 670
 671 tlv_stream!(InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef, INVOICE_REQUEST_TYPES, {
 672         (80, chain: ChainHash),
 673         (82, amount: (u64, HighZeroBytesDroppedBigSize)),
 674         (84, features: (InvoiceRequestFeatures, WithoutLength)),
 675         (86, quantity: (u64, HighZeroBytesDroppedBigSize)),
 676         (INVOICE_REQUEST_PAYER_ID_TYPE, payer_id: PublicKey),
 677         (89, payer_note: (String, WithoutLength)),
 678 });
 679
 680 type FullInvoiceRequestTlvStream =
 681         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, SignatureTlvStream);
 682
 683 #[cfg(test)]
 684 type FullInvoiceRequestTlvStreamRef<'a> = (
 685         PayerTlvStreamRef<'a>,
 686         OfferTlvStreamRef<'a>,
 687         InvoiceRequestTlvStreamRef<'a>,
 688         SignatureTlvStreamRef<'a>,
 689 );
 690
 691 impl SeekReadable for FullInvoiceRequestTlvStream {
 692         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 693                 let payer = SeekReadable::read(r)?;
 694                 let offer = SeekReadable::read(r)?;
 695                 let invoice_request = SeekReadable::read(r)?;
 696                 let signature = SeekReadable::read(r)?;
 697
 698                 Ok((payer, offer, invoice_request, signature))
 699         }
 700 }
 701
 702 type PartialInvoiceRequestTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
 703
 704 type PartialInvoiceRequestTlvStreamRef<'a> = (
 705         PayerTlvStreamRef<'a>,
 706         OfferTlvStreamRef<'a>,
 707         InvoiceRequestTlvStreamRef<'a>,
 708 );
 709
 710 impl TryFrom<Vec<u8>> for InvoiceRequest {
 711         type Error = ParseError;
 712
 713         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 714                 let invoice_request = ParsedMessage::<FullInvoiceRequestTlvStream>::try_from(bytes)?;
 715                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
 716                 let (
 717                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
 718                         SignatureTlvStream { signature },
 719                 ) = tlv_stream;
 720                 let contents = InvoiceRequestContents::try_from(
 721                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 722                 )?;
 723
 724                 let signature = match signature {
 725                         None => return Err(ParseError::InvalidSemantics(SemanticError::MissingSignature)),
 726                         Some(signature) => signature,
 727                 };
 728                 merkle::verify_signature(&signature, SIGNATURE_TAG, &bytes, contents.payer_id)?;
 729
 730                 Ok(InvoiceRequest { bytes, contents, signature })
 731         }
 732 }
 733
 734 impl TryFrom<PartialInvoiceRequestTlvStream> for InvoiceRequestContents {
 735         type Error = SemanticError;
 736
 737         fn try_from(tlv_stream: PartialInvoiceRequestTlvStream) -> Result<Self, Self::Error> {
 738                 let (
 739                         PayerTlvStream { metadata },
 740                         offer_tlv_stream,
 741                         InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
 742                 ) = tlv_stream;
 743
 744                 let payer = match metadata {
 745                         None => return Err(SemanticError::MissingPayerMetadata),
 746                         Some(metadata) => PayerContents(Metadata::Bytes(metadata)),
 747                 };
 748                 let offer = OfferContents::try_from(offer_tlv_stream)?;
 749
 750                 if !offer.supports_chain(chain.unwrap_or_else(|| offer.implied_chain())) {
 751                         return Err(SemanticError::UnsupportedChain);
 752                 }
 753
 754                 if offer.amount().is_none() && amount.is_none() {
 755                         return Err(SemanticError::MissingAmount);
 756                 }
 757
 758                 offer.check_quantity(quantity)?;
 759                 offer.check_amount_msats_for_quantity(amount, quantity)?;
 760
 761                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
 762
 763                 let payer_id = match payer_id {
 764                         None => return Err(SemanticError::MissingPayerId),
 765                         Some(payer_id) => payer_id,
 766                 };
 767
 768                 Ok(InvoiceRequestContents {
 769                         inner: InvoiceRequestContentsWithoutPayerId {
 770                                 payer, offer, chain, amount_msats: amount, features, quantity, payer_note,
 771                         },
 772                         payer_id,
 773                 })
 774         }
 775 }
 776
 777 #[cfg(test)]
 778 mod tests {
 779         use super::{InvoiceRequest, InvoiceRequestTlvStreamRef, SIGNATURE_TAG};
 780
 781         use bitcoin::blockdata::constants::ChainHash;
 782         use bitcoin::network::constants::Network;
 783         use bitcoin::secp256k1::{KeyPair, Secp256k1, SecretKey, self};
 784         use core::convert::{Infallible, TryFrom};
 785         use core::num::NonZeroU64;
 786         #[cfg(feature = "std")]
 787         use core::time::Duration;
 788         use crate::sign::KeyMaterial;
 789         use crate::ln::features::InvoiceRequestFeatures;
 790         use crate::ln::inbound_payment::ExpandedKey;
 791         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 792         use crate::offers::invoice::{Invoice, SIGNATURE_TAG as INVOICE_SIGNATURE_TAG};
 793         use crate::offers::merkle::{SignError, SignatureTlvStreamRef, self};
 794         use crate::offers::offer::{Amount, OfferBuilder, OfferTlvStreamRef, Quantity};
 795         use crate::offers::parse::{ParseError, SemanticError};
 796         use crate::offers::payer::PayerTlvStreamRef;
 797         use crate::offers::test_utils::*;
 798         use crate::util::ser::{BigSize, Writeable};
 799         use crate::util::string::PrintableString;
 800
 801         #[test]
 802         fn builds_invoice_request_with_defaults() {
 803                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 804                         .amount_msats(1000)
 805                         .build().unwrap()
 806                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 807                         .build().unwrap()
 808                         .sign(payer_sign).unwrap();
 809
 810                 let mut buffer = Vec::new();
 811                 invoice_request.write(&mut buffer).unwrap();
 812
 813                 assert_eq!(invoice_request.bytes, buffer.as_slice());
 814                 assert_eq!(invoice_request.metadata(), &[1; 32]);
 815                 assert_eq!(invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
 816                 assert_eq!(invoice_request.amount_msats(), None);
 817                 assert_eq!(invoice_request.features(), &InvoiceRequestFeatures::empty());
 818                 assert_eq!(invoice_request.quantity(), None);
 819                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
 820                 assert_eq!(invoice_request.payer_note(), None);
 821                 assert!(
 822                         merkle::verify_signature(
 823                                 &invoice_request.signature, SIGNATURE_TAG, &invoice_request.bytes, payer_pubkey()
 824                         ).is_ok()
 825                 );
 826
 827                 assert_eq!(
 828                         invoice_request.as_tlv_stream(),
 829                         (
 830                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
 831                                 OfferTlvStreamRef {
 832                                         chains: None,
 833                                         metadata: None,
 834                                         currency: None,
 835                                         amount: Some(1000),
 836                                         description: Some(&String::from("foo")),
 837                                         features: None,
 838                                         absolute_expiry: None,
 839                                         paths: None,
 840                                         issuer: None,
 841                                         quantity_max: None,
 842                                         node_id: Some(&recipient_pubkey()),
 843                                 },
 844                                 InvoiceRequestTlvStreamRef {
 845                                         chain: None,
 846                                         amount: None,
 847                                         features: None,
 848                                         quantity: None,
 849                                         payer_id: Some(&payer_pubkey()),
 850                                         payer_note: None,
 851                                 },
 852                                 SignatureTlvStreamRef { signature: Some(&invoice_request.signature()) },
 853                         ),
 854                 );
 855
 856                 if let Err(e) = InvoiceRequest::try_from(buffer) {
 857                         panic!("error parsing invoice request: {:?}", e);
 858                 }
 859         }
 860
 861         #[cfg(feature = "std")]
 862         #[test]
 863         fn builds_invoice_request_from_offer_with_expiration() {
 864                 let future_expiry = Duration::from_secs(u64::max_value());
 865                 let past_expiry = Duration::from_secs(0);
 866
 867                 if let Err(e) = OfferBuilder::new("foo".into(), recipient_pubkey())
 868                         .amount_msats(1000)
 869                         .absolute_expiry(future_expiry)
 870                         .build().unwrap()
 871                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 872                         .build()
 873                 {
 874                         panic!("error building invoice_request: {:?}", e);
 875                 }
 876
 877                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 878                         .amount_msats(1000)
 879                         .absolute_expiry(past_expiry)
 880                         .build().unwrap()
 881                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 882                         .build()
 883                 {
 884                         Ok(_) => panic!("expected error"),
 885                         Err(e) => assert_eq!(e, SemanticError::AlreadyExpired),
 886                 }
 887         }
 888
 889         #[test]
 890         fn builds_invoice_request_with_derived_metadata() {
 891                 let payer_id = payer_pubkey();
 892                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
 893                 let entropy = FixedEntropy {};
 894                 let secp_ctx = Secp256k1::new();
 895
 896                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
 897                         .amount_msats(1000)
 898                         .build().unwrap();
 899                 let invoice_request = offer
 900                         .request_invoice_deriving_metadata(payer_id, &expanded_key, &entropy)
 901                         .unwrap()
 902                         .build().unwrap()
 903                         .sign(payer_sign).unwrap();
 904                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
 905
 906                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
 907                         .unwrap()
 908                         .build().unwrap()
 909                         .sign(recipient_sign).unwrap();
 910                 assert!(invoice.verify(&expanded_key, &secp_ctx));
 911
 912                 // Fails verification with altered fields
 913                 let (
 914                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
 915                         mut invoice_tlv_stream, mut signature_tlv_stream
 916                 ) = invoice.as_tlv_stream();
 917                 invoice_request_tlv_stream.amount = Some(2000);
 918                 invoice_tlv_stream.amount = Some(2000);
 919
 920                 let tlv_stream =
 921                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
 922                 let mut bytes = Vec::new();
 923                 tlv_stream.write(&mut bytes).unwrap();
 924
 925                 let signature = merkle::sign_message(
 926                         recipient_sign, INVOICE_SIGNATURE_TAG, &bytes, recipient_pubkey()
 927                 ).unwrap();
 928                 signature_tlv_stream.signature = Some(&signature);
 929
 930                 let mut encoded_invoice = bytes;
 931                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
 932
 933                 let invoice = Invoice::try_from(encoded_invoice).unwrap();
 934                 assert!(!invoice.verify(&expanded_key, &secp_ctx));
 935
 936                 // Fails verification with altered metadata
 937                 let (
 938                         mut payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
 939                         mut signature_tlv_stream
 940                 ) = invoice.as_tlv_stream();
 941                 let metadata = payer_tlv_stream.metadata.unwrap().iter().copied().rev().collect();
 942                 payer_tlv_stream.metadata = Some(&metadata);
 943
 944                 let tlv_stream =
 945                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
 946                 let mut bytes = Vec::new();
 947                 tlv_stream.write(&mut bytes).unwrap();
 948
 949                 let signature = merkle::sign_message(
 950                         recipient_sign, INVOICE_SIGNATURE_TAG, &bytes, recipient_pubkey()
 951                 ).unwrap();
 952                 signature_tlv_stream.signature = Some(&signature);
 953
 954                 let mut encoded_invoice = bytes;
 955                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
 956
 957                 let invoice = Invoice::try_from(encoded_invoice).unwrap();
 958                 assert!(!invoice.verify(&expanded_key, &secp_ctx));
 959         }
 960
 961         #[test]
 962         fn builds_invoice_request_with_derived_payer_id() {
 963                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
 964                 let entropy = FixedEntropy {};
 965                 let secp_ctx = Secp256k1::new();
 966
 967                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
 968                         .amount_msats(1000)
 969                         .build().unwrap();
 970                 let invoice_request = offer
 971                         .request_invoice_deriving_payer_id(&expanded_key, &entropy, &secp_ctx)
 972                         .unwrap()
 973                         .build_and_sign()
 974                         .unwrap();
 975
 976                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
 977                         .unwrap()
 978                         .build().unwrap()
 979                         .sign(recipient_sign).unwrap();
 980                 assert!(invoice.verify(&expanded_key, &secp_ctx));
 981
 982                 // Fails verification with altered fields
 983                 let (
 984                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
 985                         mut invoice_tlv_stream, mut signature_tlv_stream
 986                 ) = invoice.as_tlv_stream();
 987                 invoice_request_tlv_stream.amount = Some(2000);
 988                 invoice_tlv_stream.amount = Some(2000);
 989
 990                 let tlv_stream =
 991                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
 992                 let mut bytes = Vec::new();
 993                 tlv_stream.write(&mut bytes).unwrap();
 994
 995                 let signature = merkle::sign_message(
 996                         recipient_sign, INVOICE_SIGNATURE_TAG, &bytes, recipient_pubkey()
 997                 ).unwrap();
 998                 signature_tlv_stream.signature = Some(&signature);
 999
1000                 let mut encoded_invoice = bytes;
1001                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1002
1003                 let invoice = Invoice::try_from(encoded_invoice).unwrap();
1004                 assert!(!invoice.verify(&expanded_key, &secp_ctx));
1005
1006                 // Fails verification with altered payer id
1007                 let (
1008                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream, invoice_tlv_stream,
1009                         mut signature_tlv_stream
1010                 ) = invoice.as_tlv_stream();
1011                 let payer_id = pubkey(1);
1012                 invoice_request_tlv_stream.payer_id = Some(&payer_id);
1013
1014                 let tlv_stream =
1015                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1016                 let mut bytes = Vec::new();
1017                 tlv_stream.write(&mut bytes).unwrap();
1018
1019                 let signature = merkle::sign_message(
1020                         recipient_sign, INVOICE_SIGNATURE_TAG, &bytes, recipient_pubkey()
1021                 ).unwrap();
1022                 signature_tlv_stream.signature = Some(&signature);
1023
1024                 let mut encoded_invoice = bytes;
1025                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1026
1027                 let invoice = Invoice::try_from(encoded_invoice).unwrap();
1028                 assert!(!invoice.verify(&expanded_key, &secp_ctx));
1029         }
1030
1031         #[test]
1032         fn builds_invoice_request_with_chain() {
1033                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
1034                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
1035
1036                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1037                         .amount_msats(1000)
1038                         .build().unwrap()
1039                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1040                         .chain(Network::Bitcoin).unwrap()
1041                         .build().unwrap()
1042                         .sign(payer_sign).unwrap();
1043                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1044                 assert_eq!(invoice_request.chain(), mainnet);
1045                 assert_eq!(tlv_stream.chain, None);
1046
1047                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1048                         .amount_msats(1000)
1049                         .chain(Network::Testnet)
1050                         .build().unwrap()
1051                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1052                         .chain(Network::Testnet).unwrap()
1053                         .build().unwrap()
1054                         .sign(payer_sign).unwrap();
1055                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1056                 assert_eq!(invoice_request.chain(), testnet);
1057                 assert_eq!(tlv_stream.chain, Some(&testnet));
1058
1059                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1060                         .amount_msats(1000)
1061                         .chain(Network::Bitcoin)
1062                         .chain(Network::Testnet)
1063                         .build().unwrap()
1064                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1065                         .chain(Network::Bitcoin).unwrap()
1066                         .build().unwrap()
1067                         .sign(payer_sign).unwrap();
1068                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1069                 assert_eq!(invoice_request.chain(), mainnet);
1070                 assert_eq!(tlv_stream.chain, None);
1071
1072                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1073                         .amount_msats(1000)
1074                         .chain(Network::Bitcoin)
1075                         .chain(Network::Testnet)
1076                         .build().unwrap()
1077                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1078                         .chain(Network::Bitcoin).unwrap()
1079                         .chain(Network::Testnet).unwrap()
1080                         .build().unwrap()
1081                         .sign(payer_sign).unwrap();
1082                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1083                 assert_eq!(invoice_request.chain(), testnet);
1084                 assert_eq!(tlv_stream.chain, Some(&testnet));
1085
1086                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1087                         .amount_msats(1000)
1088                         .chain(Network::Testnet)
1089                         .build().unwrap()
1090                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1091                         .chain(Network::Bitcoin)
1092                 {
1093                         Ok(_) => panic!("expected error"),
1094                         Err(e) => assert_eq!(e, SemanticError::UnsupportedChain),
1095                 }
1096
1097                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1098                         .amount_msats(1000)
1099                         .chain(Network::Testnet)
1100                         .build().unwrap()
1101                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1102                         .build()
1103                 {
1104                         Ok(_) => panic!("expected error"),
1105                         Err(e) => assert_eq!(e, SemanticError::UnsupportedChain),
1106                 }
1107         }
1108
1109         #[test]
1110         fn builds_invoice_request_with_amount() {
1111                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1112                         .amount_msats(1000)
1113                         .build().unwrap()
1114                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1115                         .amount_msats(1000).unwrap()
1116                         .build().unwrap()
1117                         .sign(payer_sign).unwrap();
1118                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1119                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1120                 assert_eq!(tlv_stream.amount, Some(1000));
1121
1122                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1123                         .amount_msats(1000)
1124                         .build().unwrap()
1125                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1126                         .amount_msats(1001).unwrap()
1127                         .amount_msats(1000).unwrap()
1128                         .build().unwrap()
1129                         .sign(payer_sign).unwrap();
1130                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1131                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1132                 assert_eq!(tlv_stream.amount, Some(1000));
1133
1134                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1135                         .amount_msats(1000)
1136                         .build().unwrap()
1137                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1138                         .amount_msats(1001).unwrap()
1139                         .build().unwrap()
1140                         .sign(payer_sign).unwrap();
1141                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1142                 assert_eq!(invoice_request.amount_msats(), Some(1001));
1143                 assert_eq!(tlv_stream.amount, Some(1001));
1144
1145                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1146                         .amount_msats(1000)
1147                         .build().unwrap()
1148                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1149                         .amount_msats(999)
1150                 {
1151                         Ok(_) => panic!("expected error"),
1152                         Err(e) => assert_eq!(e, SemanticError::InsufficientAmount),
1153                 }
1154
1155                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1156                         .amount_msats(1000)
1157                         .supported_quantity(Quantity::Unbounded)
1158                         .build().unwrap()
1159                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1160                         .quantity(2).unwrap()
1161                         .amount_msats(1000)
1162                 {
1163                         Ok(_) => panic!("expected error"),
1164                         Err(e) => assert_eq!(e, SemanticError::InsufficientAmount),
1165                 }
1166
1167                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1168                         .amount_msats(1000)
1169                         .build().unwrap()
1170                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1171                         .amount_msats(MAX_VALUE_MSAT + 1)
1172                 {
1173                         Ok(_) => panic!("expected error"),
1174                         Err(e) => assert_eq!(e, SemanticError::InvalidAmount),
1175                 }
1176
1177                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1178                         .amount_msats(1000)
1179                         .supported_quantity(Quantity::Unbounded)
1180                         .build().unwrap()
1181                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1182                         .amount_msats(1000).unwrap()
1183                         .quantity(2).unwrap()
1184                         .build()
1185                 {
1186                         Ok(_) => panic!("expected error"),
1187                         Err(e) => assert_eq!(e, SemanticError::InsufficientAmount),
1188                 }
1189
1190                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1191                         .build().unwrap()
1192                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1193                         .build()
1194                 {
1195                         Ok(_) => panic!("expected error"),
1196                         Err(e) => assert_eq!(e, SemanticError::MissingAmount),
1197                 }
1198
1199                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1200                         .amount_msats(1000)
1201                         .supported_quantity(Quantity::Unbounded)
1202                         .build().unwrap()
1203                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1204                         .quantity(u64::max_value()).unwrap()
1205                         .build()
1206                 {
1207                         Ok(_) => panic!("expected error"),
1208                         Err(e) => assert_eq!(e, SemanticError::InvalidAmount),
1209                 }
1210         }
1211
1212         #[test]
1213         fn builds_invoice_request_with_features() {
1214                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1215                         .amount_msats(1000)
1216                         .build().unwrap()
1217                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1218                         .features_unchecked(InvoiceRequestFeatures::unknown())
1219                         .build().unwrap()
1220                         .sign(payer_sign).unwrap();
1221                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1222                 assert_eq!(invoice_request.features(), &InvoiceRequestFeatures::unknown());
1223                 assert_eq!(tlv_stream.features, Some(&InvoiceRequestFeatures::unknown()));
1224
1225                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1226                         .amount_msats(1000)
1227                         .build().unwrap()
1228                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1229                         .features_unchecked(InvoiceRequestFeatures::unknown())
1230                         .features_unchecked(InvoiceRequestFeatures::empty())
1231                         .build().unwrap()
1232                         .sign(payer_sign).unwrap();
1233                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1234                 assert_eq!(invoice_request.features(), &InvoiceRequestFeatures::empty());
1235                 assert_eq!(tlv_stream.features, None);
1236         }
1237
1238         #[test]
1239         fn builds_invoice_request_with_quantity() {
1240                 let one = NonZeroU64::new(1).unwrap();
1241                 let ten = NonZeroU64::new(10).unwrap();
1242
1243                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1244                         .amount_msats(1000)
1245                         .supported_quantity(Quantity::One)
1246                         .build().unwrap()
1247                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1248                         .build().unwrap()
1249                         .sign(payer_sign).unwrap();
1250                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1251                 assert_eq!(invoice_request.quantity(), None);
1252                 assert_eq!(tlv_stream.quantity, None);
1253
1254                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1255                         .amount_msats(1000)
1256                         .supported_quantity(Quantity::One)
1257                         .build().unwrap()
1258                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1259                         .amount_msats(2_000).unwrap()
1260                         .quantity(2)
1261                 {
1262                         Ok(_) => panic!("expected error"),
1263                         Err(e) => assert_eq!(e, SemanticError::UnexpectedQuantity),
1264                 }
1265
1266                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1267                         .amount_msats(1000)
1268                         .supported_quantity(Quantity::Bounded(ten))
1269                         .build().unwrap()
1270                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1271                         .amount_msats(10_000).unwrap()
1272                         .quantity(10).unwrap()
1273                         .build().unwrap()
1274                         .sign(payer_sign).unwrap();
1275                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1276                 assert_eq!(invoice_request.amount_msats(), Some(10_000));
1277                 assert_eq!(tlv_stream.amount, Some(10_000));
1278
1279                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1280                         .amount_msats(1000)
1281                         .supported_quantity(Quantity::Bounded(ten))
1282                         .build().unwrap()
1283                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1284                         .amount_msats(11_000).unwrap()
1285                         .quantity(11)
1286                 {
1287                         Ok(_) => panic!("expected error"),
1288                         Err(e) => assert_eq!(e, SemanticError::InvalidQuantity),
1289                 }
1290
1291                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1292                         .amount_msats(1000)
1293                         .supported_quantity(Quantity::Unbounded)
1294                         .build().unwrap()
1295                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1296                         .amount_msats(2_000).unwrap()
1297                         .quantity(2).unwrap()
1298                         .build().unwrap()
1299                         .sign(payer_sign).unwrap();
1300                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1301                 assert_eq!(invoice_request.amount_msats(), Some(2_000));
1302                 assert_eq!(tlv_stream.amount, Some(2_000));
1303
1304                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1305                         .amount_msats(1000)
1306                         .supported_quantity(Quantity::Unbounded)
1307                         .build().unwrap()
1308                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1309                         .build()
1310                 {
1311                         Ok(_) => panic!("expected error"),
1312                         Err(e) => assert_eq!(e, SemanticError::MissingQuantity),
1313                 }
1314
1315                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1316                         .amount_msats(1000)
1317                         .supported_quantity(Quantity::Bounded(one))
1318                         .build().unwrap()
1319                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1320                         .build()
1321                 {
1322                         Ok(_) => panic!("expected error"),
1323                         Err(e) => assert_eq!(e, SemanticError::MissingQuantity),
1324                 }
1325         }
1326
1327         #[test]
1328         fn builds_invoice_request_with_payer_note() {
1329                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1330                         .amount_msats(1000)
1331                         .build().unwrap()
1332                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1333                         .payer_note("bar".into())
1334                         .build().unwrap()
1335                         .sign(payer_sign).unwrap();
1336                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1337                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("bar")));
1338                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
1339
1340                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1341                         .amount_msats(1000)
1342                         .build().unwrap()
1343                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1344                         .payer_note("bar".into())
1345                         .payer_note("baz".into())
1346                         .build().unwrap()
1347                         .sign(payer_sign).unwrap();
1348                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1349                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("baz")));
1350                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
1351         }
1352
1353         #[test]
1354         fn fails_signing_invoice_request() {
1355                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1356                         .amount_msats(1000)
1357                         .build().unwrap()
1358                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1359                         .build().unwrap()
1360                         .sign(|_| Err(()))
1361                 {
1362                         Ok(_) => panic!("expected error"),
1363                         Err(e) => assert_eq!(e, SignError::Signing(())),
1364                 }
1365
1366                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1367                         .amount_msats(1000)
1368                         .build().unwrap()
1369                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1370                         .build().unwrap()
1371                         .sign(recipient_sign)
1372                 {
1373                         Ok(_) => panic!("expected error"),
1374                         Err(e) => assert_eq!(e, SignError::Verification(secp256k1::Error::InvalidSignature)),
1375                 }
1376         }
1377
1378         #[test]
1379         fn fails_responding_with_unknown_required_features() {
1380                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1381                         .amount_msats(1000)
1382                         .build().unwrap()
1383                         .request_invoice(vec![42; 32], payer_pubkey()).unwrap()
1384                         .features_unchecked(InvoiceRequestFeatures::unknown())
1385                         .build().unwrap()
1386                         .sign(payer_sign).unwrap()
1387                         .respond_with_no_std(payment_paths(), payment_hash(), now())
1388                 {
1389                         Ok(_) => panic!("expected error"),
1390                         Err(e) => assert_eq!(e, SemanticError::UnknownRequiredFeatures),
1391                 }
1392         }
1393
1394         #[test]
1395         fn parses_invoice_request_with_metadata() {
1396                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1397                         .amount_msats(1000)
1398                         .build().unwrap()
1399                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1400                         .build().unwrap()
1401                         .sign(payer_sign).unwrap();
1402
1403                 let mut buffer = Vec::new();
1404                 invoice_request.write(&mut buffer).unwrap();
1405
1406                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1407                         panic!("error parsing invoice_request: {:?}", e);
1408                 }
1409         }
1410
1411         #[test]
1412         fn parses_invoice_request_with_chain() {
1413                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1414                         .amount_msats(1000)
1415                         .build().unwrap()
1416                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1417                         .chain(Network::Bitcoin).unwrap()
1418                         .build().unwrap()
1419                         .sign(payer_sign).unwrap();
1420
1421                 let mut buffer = Vec::new();
1422                 invoice_request.write(&mut buffer).unwrap();
1423
1424                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1425                         panic!("error parsing invoice_request: {:?}", e);
1426                 }
1427
1428                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1429                         .amount_msats(1000)
1430                         .build().unwrap()
1431                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1432                         .chain_unchecked(Network::Testnet)
1433                         .build_unchecked()
1434                         .sign(payer_sign).unwrap();
1435
1436                 let mut buffer = Vec::new();
1437                 invoice_request.write(&mut buffer).unwrap();
1438
1439                 match InvoiceRequest::try_from(buffer) {
1440                         Ok(_) => panic!("expected error"),
1441                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnsupportedChain)),
1442                 }
1443         }
1444
1445         #[test]
1446         fn parses_invoice_request_with_amount() {
1447                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1448                         .amount_msats(1000)
1449                         .build().unwrap()
1450                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1451                         .build().unwrap()
1452                         .sign(payer_sign).unwrap();
1453
1454                 let mut buffer = Vec::new();
1455                 invoice_request.write(&mut buffer).unwrap();
1456
1457                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1458                         panic!("error parsing invoice_request: {:?}", e);
1459                 }
1460
1461                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1462                         .build().unwrap()
1463                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1464                         .amount_msats(1000).unwrap()
1465                         .build().unwrap()
1466                         .sign(payer_sign).unwrap();
1467
1468                 let mut buffer = Vec::new();
1469                 invoice_request.write(&mut buffer).unwrap();
1470
1471                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1472                         panic!("error parsing invoice_request: {:?}", e);
1473                 }
1474
1475                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1476                         .build().unwrap()
1477                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1478                         .build_unchecked()
1479                         .sign(payer_sign).unwrap();
1480
1481                 let mut buffer = Vec::new();
1482                 invoice_request.write(&mut buffer).unwrap();
1483
1484                 match InvoiceRequest::try_from(buffer) {
1485                         Ok(_) => panic!("expected error"),
1486                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingAmount)),
1487                 }
1488
1489                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1490                         .amount_msats(1000)
1491                         .build().unwrap()
1492                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1493                         .amount_msats_unchecked(999)
1494                         .build_unchecked()
1495                         .sign(payer_sign).unwrap();
1496
1497                 let mut buffer = Vec::new();
1498                 invoice_request.write(&mut buffer).unwrap();
1499
1500                 match InvoiceRequest::try_from(buffer) {
1501                         Ok(_) => panic!("expected error"),
1502                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::InsufficientAmount)),
1503                 }
1504
1505                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1506                         .amount(Amount::Currency { iso4217_code: *b"USD", amount: 1000 })
1507                         .build_unchecked()
1508                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1509                         .build_unchecked()
1510                         .sign(payer_sign).unwrap();
1511
1512                 let mut buffer = Vec::new();
1513                 invoice_request.write(&mut buffer).unwrap();
1514
1515                 match InvoiceRequest::try_from(buffer) {
1516                         Ok(_) => panic!("expected error"),
1517                         Err(e) => {
1518                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnsupportedCurrency));
1519                         },
1520                 }
1521
1522                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1523                         .amount_msats(1000)
1524                         .supported_quantity(Quantity::Unbounded)
1525                         .build().unwrap()
1526                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1527                         .quantity(u64::max_value()).unwrap()
1528                         .build_unchecked()
1529                         .sign(payer_sign).unwrap();
1530
1531                 let mut buffer = Vec::new();
1532                 invoice_request.write(&mut buffer).unwrap();
1533
1534                 match InvoiceRequest::try_from(buffer) {
1535                         Ok(_) => panic!("expected error"),
1536                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::InvalidAmount)),
1537                 }
1538         }
1539
1540         #[test]
1541         fn parses_invoice_request_with_quantity() {
1542                 let one = NonZeroU64::new(1).unwrap();
1543                 let ten = NonZeroU64::new(10).unwrap();
1544
1545                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1546                         .amount_msats(1000)
1547                         .supported_quantity(Quantity::One)
1548                         .build().unwrap()
1549                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1550                         .build().unwrap()
1551                         .sign(payer_sign).unwrap();
1552
1553                 let mut buffer = Vec::new();
1554                 invoice_request.write(&mut buffer).unwrap();
1555
1556                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1557                         panic!("error parsing invoice_request: {:?}", e);
1558                 }
1559
1560                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1561                         .amount_msats(1000)
1562                         .supported_quantity(Quantity::One)
1563                         .build().unwrap()
1564                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1565                         .amount_msats(2_000).unwrap()
1566                         .quantity_unchecked(2)
1567                         .build_unchecked()
1568                         .sign(payer_sign).unwrap();
1569
1570                 let mut buffer = Vec::new();
1571                 invoice_request.write(&mut buffer).unwrap();
1572
1573                 match InvoiceRequest::try_from(buffer) {
1574                         Ok(_) => panic!("expected error"),
1575                         Err(e) => {
1576                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedQuantity));
1577                         },
1578                 }
1579
1580                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1581                         .amount_msats(1000)
1582                         .supported_quantity(Quantity::Bounded(ten))
1583                         .build().unwrap()
1584                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1585                         .amount_msats(10_000).unwrap()
1586                         .quantity(10).unwrap()
1587                         .build().unwrap()
1588                         .sign(payer_sign).unwrap();
1589
1590                 let mut buffer = Vec::new();
1591                 invoice_request.write(&mut buffer).unwrap();
1592
1593                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1594                         panic!("error parsing invoice_request: {:?}", e);
1595                 }
1596
1597                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1598                         .amount_msats(1000)
1599                         .supported_quantity(Quantity::Bounded(ten))
1600                         .build().unwrap()
1601                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1602                         .amount_msats(11_000).unwrap()
1603                         .quantity_unchecked(11)
1604                         .build_unchecked()
1605                         .sign(payer_sign).unwrap();
1606
1607                 let mut buffer = Vec::new();
1608                 invoice_request.write(&mut buffer).unwrap();
1609
1610                 match InvoiceRequest::try_from(buffer) {
1611                         Ok(_) => panic!("expected error"),
1612                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::InvalidQuantity)),
1613                 }
1614
1615                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1616                         .amount_msats(1000)
1617                         .supported_quantity(Quantity::Unbounded)
1618                         .build().unwrap()
1619                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1620                         .amount_msats(2_000).unwrap()
1621                         .quantity(2).unwrap()
1622                         .build().unwrap()
1623                         .sign(payer_sign).unwrap();
1624
1625                 let mut buffer = Vec::new();
1626                 invoice_request.write(&mut buffer).unwrap();
1627
1628                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1629                         panic!("error parsing invoice_request: {:?}", e);
1630                 }
1631
1632                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1633                         .amount_msats(1000)
1634                         .supported_quantity(Quantity::Unbounded)
1635                         .build().unwrap()
1636                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1637                         .build_unchecked()
1638                         .sign(payer_sign).unwrap();
1639
1640                 let mut buffer = Vec::new();
1641                 invoice_request.write(&mut buffer).unwrap();
1642
1643                 match InvoiceRequest::try_from(buffer) {
1644                         Ok(_) => panic!("expected error"),
1645                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingQuantity)),
1646                 }
1647
1648                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1649                         .amount_msats(1000)
1650                         .supported_quantity(Quantity::Bounded(one))
1651                         .build().unwrap()
1652                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1653                         .build_unchecked()
1654                         .sign(payer_sign).unwrap();
1655
1656                 let mut buffer = Vec::new();
1657                 invoice_request.write(&mut buffer).unwrap();
1658
1659                 match InvoiceRequest::try_from(buffer) {
1660                         Ok(_) => panic!("expected error"),
1661                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingQuantity)),
1662                 }
1663         }
1664
1665         #[test]
1666         fn fails_parsing_invoice_request_without_metadata() {
1667                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1668                         .amount_msats(1000)
1669                         .build().unwrap();
1670                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1671                         .build().unwrap();
1672                 let mut tlv_stream = unsigned_invoice_request.invoice_request.as_tlv_stream();
1673                 tlv_stream.0.metadata = None;
1674
1675                 let mut buffer = Vec::new();
1676                 tlv_stream.write(&mut buffer).unwrap();
1677
1678                 match InvoiceRequest::try_from(buffer) {
1679                         Ok(_) => panic!("expected error"),
1680                         Err(e) => {
1681                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPayerMetadata));
1682                         },
1683                 }
1684         }
1685
1686         #[test]
1687         fn fails_parsing_invoice_request_without_payer_id() {
1688                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1689                         .amount_msats(1000)
1690                         .build().unwrap();
1691                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1692                         .build().unwrap();
1693                 let mut tlv_stream = unsigned_invoice_request.invoice_request.as_tlv_stream();
1694                 tlv_stream.2.payer_id = None;
1695
1696                 let mut buffer = Vec::new();
1697                 tlv_stream.write(&mut buffer).unwrap();
1698
1699                 match InvoiceRequest::try_from(buffer) {
1700                         Ok(_) => panic!("expected error"),
1701                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPayerId)),
1702                 }
1703         }
1704
1705         #[test]
1706         fn fails_parsing_invoice_request_without_node_id() {
1707                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1708                         .amount_msats(1000)
1709                         .build().unwrap();
1710                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1711                         .build().unwrap();
1712                 let mut tlv_stream = unsigned_invoice_request.invoice_request.as_tlv_stream();
1713                 tlv_stream.1.node_id = None;
1714
1715                 let mut buffer = Vec::new();
1716                 tlv_stream.write(&mut buffer).unwrap();
1717
1718                 match InvoiceRequest::try_from(buffer) {
1719                         Ok(_) => panic!("expected error"),
1720                         Err(e) => {
1721                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingSigningPubkey));
1722                         },
1723                 }
1724         }
1725
1726         #[test]
1727         fn fails_parsing_invoice_request_without_signature() {
1728                 let mut buffer = Vec::new();
1729                 OfferBuilder::new("foo".into(), recipient_pubkey())
1730                         .amount_msats(1000)
1731                         .build().unwrap()
1732                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1733                         .build().unwrap()
1734                         .invoice_request
1735                         .write(&mut buffer).unwrap();
1736
1737                 match InvoiceRequest::try_from(buffer) {
1738                         Ok(_) => panic!("expected error"),
1739                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingSignature)),
1740                 }
1741         }
1742
1743         #[test]
1744         fn fails_parsing_invoice_request_with_invalid_signature() {
1745                 let mut invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1746                         .amount_msats(1000)
1747                         .build().unwrap()
1748                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1749                         .build().unwrap()
1750                         .sign(payer_sign).unwrap();
1751                 let last_signature_byte = invoice_request.bytes.last_mut().unwrap();
1752                 *last_signature_byte = last_signature_byte.wrapping_add(1);
1753
1754                 let mut buffer = Vec::new();
1755                 invoice_request.write(&mut buffer).unwrap();
1756
1757                 match InvoiceRequest::try_from(buffer) {
1758                         Ok(_) => panic!("expected error"),
1759                         Err(e) => {
1760                                 assert_eq!(e, ParseError::InvalidSignature(secp256k1::Error::InvalidSignature));
1761                         },
1762                 }
1763         }
1764
1765         #[test]
1766         fn fails_parsing_invoice_request_with_extra_tlv_records() {
1767                 let secp_ctx = Secp256k1::new();
1768                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1769                 let invoice_request = OfferBuilder::new("foo".into(), keys.public_key())
1770                         .amount_msats(1000)
1771                         .build().unwrap()
1772                         .request_invoice(vec![1; 32], keys.public_key()).unwrap()
1773                         .build().unwrap()
1774                         .sign::<_, Infallible>(|digest| Ok(secp_ctx.sign_schnorr_no_aux_rand(digest, &keys)))
1775                         .unwrap();
1776
1777                 let mut encoded_invoice_request = Vec::new();
1778                 invoice_request.write(&mut encoded_invoice_request).unwrap();
1779                 BigSize(1002).write(&mut encoded_invoice_request).unwrap();
1780                 BigSize(32).write(&mut encoded_invoice_request).unwrap();
1781                 [42u8; 32].write(&mut encoded_invoice_request).unwrap();
1782
1783                 match InvoiceRequest::try_from(encoded_invoice_request) {
1784                         Ok(_) => panic!("expected error"),
1785                         Err(e) => assert_eq!(e, ParseError::Decode(DecodeError::InvalidValue)),
1786                 }
1787         }
1788 }