_ Git - rust-lightning/blob - lightning/src/offers/invoice.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` messages.
  11 //!
  12 //! An [`Invoice`] can be built from a parsed [`InvoiceRequest`] for the "offer to be paid" flow or
  13 //! from a [`Refund`] as an "offer for money" flow. The expected recipient of the payment then sends
  14 //! the invoice to the intended payer, who will then pay it.
  15 //!
  16 //! The payment recipient must include a [`PaymentHash`], so as to reveal the preimage upon payment
  17 //! receipt, and one or more [`BlindedPath`]s for the payer to use when sending the payment.
  18 //!
  19 //! ```
  20 //! extern crate bitcoin;
  21 //! extern crate lightning;
  22 //!
  23 //! use bitcoin::hashes::Hash;
  24 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
  25 //! use core::convert::{Infallible, TryFrom};
  26 //! use lightning::offers::invoice_request::InvoiceRequest;
  27 //! use lightning::offers::refund::Refund;
  28 //! use lightning::util::ser::Writeable;
  29 //!
  30 //! # use lightning::ln::PaymentHash;
  31 //! # use lightning::offers::invoice::BlindedPayInfo;
  32 //! # use lightning::onion_message::BlindedPath;
  33 //! #
  34 //! # fn create_payment_paths() -> Vec<(BlindedPath, BlindedPayInfo)> { unimplemented!() }
  35 //! # fn create_payment_hash() -> PaymentHash { unimplemented!() }
  36 //! #
  37 //! # fn parse_invoice_request(bytes: Vec<u8>) -> Result<(), lightning::offers::parse::ParseError> {
  38 //! let payment_paths = create_payment_paths();
  39 //! let payment_hash = create_payment_hash();
  40 //! let secp_ctx = Secp256k1::new();
  41 //! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32])?);
  42 //! let pubkey = PublicKey::from(keys);
  43 //! let wpubkey_hash = bitcoin::util::key::PublicKey::new(pubkey).wpubkey_hash().unwrap();
  44 //! let mut buffer = Vec::new();
  45 //!
  46 //! // Invoice for the "offer to be paid" flow.
  47 //! InvoiceRequest::try_from(bytes)?
  48 #![cfg_attr(feature = "std", doc = "
  49     .respond_with(payment_paths, payment_hash)?
  50 ")]
  51 #![cfg_attr(not(feature = "std"), doc = "
  52     .respond_with_no_std(payment_paths, payment_hash, core::time::Duration::from_secs(0))?
  53 ")]
  54 //!     .relative_expiry(3600)
  55 //!     .allow_mpp()
  56 //!     .fallback_v0_p2wpkh(&wpubkey_hash)
  57 //!     .build()?
  58 //!     .sign::<_, Infallible>(|digest| Ok(secp_ctx.sign_schnorr_no_aux_rand(digest, &keys)))
  59 //!     .expect("failed verifying signature")
  60 //!     .write(&mut buffer)
  61 //!     .unwrap();
  62 //! # Ok(())
  63 //! # }
  64 //!
  65 //! # fn parse_refund(bytes: Vec<u8>) -> Result<(), lightning::offers::parse::ParseError> {
  66 //! # let payment_paths = create_payment_paths();
  67 //! # let payment_hash = create_payment_hash();
  68 //! # let secp_ctx = Secp256k1::new();
  69 //! # let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32])?);
  70 //! # let pubkey = PublicKey::from(keys);
  71 //! # let wpubkey_hash = bitcoin::util::key::PublicKey::new(pubkey).wpubkey_hash().unwrap();
  72 //! # let mut buffer = Vec::new();
  73 //!
  74 //! // Invoice for the "offer for money" flow.
  75 //! "lnr1qcp4256ypq"
  76 //!     .parse::<Refund>()?
  77 #![cfg_attr(feature = "std", doc = "
  78     .respond_with(payment_paths, payment_hash, pubkey)?
  79 ")]
  80 #![cfg_attr(not(feature = "std"), doc = "
  81     .respond_with_no_std(payment_paths, payment_hash, pubkey, core::time::Duration::from_secs(0))?
  82 ")]
  83 //!     .relative_expiry(3600)
  84 //!     .allow_mpp()
  85 //!     .fallback_v0_p2wpkh(&wpubkey_hash)
  86 //!     .build()?
  87 //!     .sign::<_, Infallible>(|digest| Ok(secp_ctx.sign_schnorr_no_aux_rand(digest, &keys)))
  88 //!     .expect("failed verifying signature")
  89 //!     .write(&mut buffer)
  90 //!     .unwrap();
  91 //! # Ok(())
  92 //! # }
  93 //!
  94 //! ```
  95
  96 use bitcoin::blockdata::constants::ChainHash;
  97 use bitcoin::hash_types::{WPubkeyHash, WScriptHash};
  98 use bitcoin::hashes::Hash;
  99 use bitcoin::network::constants::Network;
 100 use bitcoin::secp256k1::{Message, PublicKey};
 101 use bitcoin::secp256k1::schnorr::Signature;
 102 use bitcoin::util::address::{Address, Payload, WitnessVersion};
 103 use bitcoin::util::schnorr::TweakedPublicKey;
 104 use core::convert::TryFrom;
 105 use core::time::Duration;
 106 use crate::io;
 107 use crate::ln::PaymentHash;
 108 use crate::ln::features::{BlindedHopFeatures, Bolt12InvoiceFeatures};
 109 use crate::ln::msgs::DecodeError;
 110 use crate::offers::invoice_request::{InvoiceRequest, InvoiceRequestContents, InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef};
 111 use crate::offers::merkle::{SignError, SignatureTlvStream, SignatureTlvStreamRef, WithoutSignatures, self};
 112 use crate::offers::offer::{Amount, OfferTlvStream, OfferTlvStreamRef};
 113 use crate::offers::parse::{ParseError, ParsedMessage, SemanticError};
 114 use crate::offers::payer::{PayerTlvStream, PayerTlvStreamRef};
 115 use crate::offers::refund::{Refund, RefundContents};
 116 use crate::onion_message::BlindedPath;
 117 use crate::util::ser::{HighZeroBytesDroppedBigSize, Iterable, SeekReadable, WithoutLength, Writeable, Writer};
 118
 119 use crate::prelude::*;
 120
 121 #[cfg(feature = "std")]
 122 use std::time::SystemTime;
 123
 124 const DEFAULT_RELATIVE_EXPIRY: Duration = Duration::from_secs(7200);
 125
 126 const SIGNATURE_TAG: &'static str = concat!("lightning", "invoice", "signature");
 127
 128 /// Builds an [`Invoice`] from either:
 129 /// - an [`InvoiceRequest`] for the "offer to be paid" flow or
 130 /// - a [`Refund`] for the "offer for money" flow.
 131 ///
 132 /// See [module-level documentation] for usage.
 133 ///
 134 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 135 /// [`Refund`]: crate::offers::refund::Refund
 136 /// [module-level documentation]: self
 137 pub struct InvoiceBuilder<'a> {
 138         invreq_bytes: &'a Vec<u8>,
 139         invoice: InvoiceContents,
 140 }
 141
 142 impl<'a> InvoiceBuilder<'a> {
 143         pub(super) fn for_offer(
 144                 invoice_request: &'a InvoiceRequest, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>,
 145                 created_at: Duration, payment_hash: PaymentHash
 146         ) -> Result<Self, SemanticError> {
 147                 let amount_msats = match invoice_request.amount_msats() {
 148                         Some(amount_msats) => amount_msats,
 149                         None => match invoice_request.contents.offer.amount() {
 150                                 Some(Amount::Bitcoin { amount_msats }) => {
 151                                         amount_msats.checked_mul(invoice_request.quantity().unwrap_or(1))
 152                                                 .ok_or(SemanticError::InvalidAmount)?
 153                                 },
 154                                 Some(Amount::Currency { .. }) => return Err(SemanticError::UnsupportedCurrency),
 155                                 None => return Err(SemanticError::MissingAmount),
 156                         },
 157                 };
 158
 159                 let contents = InvoiceContents::ForOffer {
 160                         invoice_request: invoice_request.contents.clone(),
 161                         fields: InvoiceFields {
 162                                 payment_paths, created_at, relative_expiry: None, payment_hash, amount_msats,
 163                                 fallbacks: None, features: Bolt12InvoiceFeatures::empty(),
 164                                 signing_pubkey: invoice_request.contents.offer.signing_pubkey(),
 165                         },
 166                 };
 167
 168                 Self::new(&invoice_request.bytes, contents)
 169         }
 170
 171         pub(super) fn for_refund(
 172                 refund: &'a Refund, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>, created_at: Duration,
 173                 payment_hash: PaymentHash, signing_pubkey: PublicKey
 174         ) -> Result<Self, SemanticError> {
 175                 let contents = InvoiceContents::ForRefund {
 176                         refund: refund.contents.clone(),
 177                         fields: InvoiceFields {
 178                                 payment_paths, created_at, relative_expiry: None, payment_hash,
 179                                 amount_msats: refund.amount_msats(), fallbacks: None,
 180                                 features: Bolt12InvoiceFeatures::empty(), signing_pubkey,
 181                         },
 182                 };
 183
 184                 Self::new(&refund.bytes, contents)
 185         }
 186
 187         fn new(invreq_bytes: &'a Vec<u8>, contents: InvoiceContents) -> Result<Self, SemanticError> {
 188                 if contents.fields().payment_paths.is_empty() {
 189                         return Err(SemanticError::MissingPaths);
 190                 }
 191
 192                 Ok(Self { invreq_bytes, invoice: contents })
 193         }
 194
 195         /// Sets the [`Invoice::relative_expiry`] as seconds since [`Invoice::created_at`]. Any expiry
 196         /// that has already passed is valid and can be checked for using [`Invoice::is_expired`].
 197         ///
 198         /// Successive calls to this method will override the previous setting.
 199         pub fn relative_expiry(mut self, relative_expiry_secs: u32) -> Self {
 200                 let relative_expiry = Duration::from_secs(relative_expiry_secs as u64);
 201                 self.invoice.fields_mut().relative_expiry = Some(relative_expiry);
 202                 self
 203         }
 204
 205         /// Adds a P2WSH address to [`Invoice::fallbacks`].
 206         ///
 207         /// Successive calls to this method will add another address. Caller is responsible for not
 208         /// adding duplicate addresses and only calling if capable of receiving to P2WSH addresses.
 209         pub fn fallback_v0_p2wsh(mut self, script_hash: &WScriptHash) -> Self {
 210                 let address = FallbackAddress {
 211                         version: WitnessVersion::V0.to_num(),
 212                         program: Vec::from(&script_hash.into_inner()[..]),
 213                 };
 214                 self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
 215                 self
 216         }
 217
 218         /// Adds a P2WPKH address to [`Invoice::fallbacks`].
 219         ///
 220         /// Successive calls to this method will add another address. Caller is responsible for not
 221         /// adding duplicate addresses and only calling if capable of receiving to P2WPKH addresses.
 222         pub fn fallback_v0_p2wpkh(mut self, pubkey_hash: &WPubkeyHash) -> Self {
 223                 let address = FallbackAddress {
 224                         version: WitnessVersion::V0.to_num(),
 225                         program: Vec::from(&pubkey_hash.into_inner()[..]),
 226                 };
 227                 self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
 228                 self
 229         }
 230
 231         /// Adds a P2TR address to [`Invoice::fallbacks`].
 232         ///
 233         /// Successive calls to this method will add another address. Caller is responsible for not
 234         /// adding duplicate addresses and only calling if capable of receiving to P2TR addresses.
 235         pub fn fallback_v1_p2tr_tweaked(mut self, output_key: &TweakedPublicKey) -> Self {
 236                 let address = FallbackAddress {
 237                         version: WitnessVersion::V1.to_num(),
 238                         program: Vec::from(&output_key.serialize()[..]),
 239                 };
 240                 self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
 241                 self
 242         }
 243
 244         /// Sets [`Invoice::features`] to indicate MPP may be used. Otherwise, MPP is disallowed.
 245         pub fn allow_mpp(mut self) -> Self {
 246                 self.invoice.fields_mut().features.set_basic_mpp_optional();
 247                 self
 248         }
 249
 250         /// Builds an unsigned [`Invoice`] after checking for valid semantics. It can be signed by
 251         /// [`UnsignedInvoice::sign`].
 252         pub fn build(self) -> Result<UnsignedInvoice<'a>, SemanticError> {
 253                 #[cfg(feature = "std")] {
 254                         if self.invoice.is_offer_or_refund_expired() {
 255                                 return Err(SemanticError::AlreadyExpired);
 256                         }
 257                 }
 258
 259                 let InvoiceBuilder { invreq_bytes, invoice } = self;
 260                 Ok(UnsignedInvoice { invreq_bytes, invoice })
 261         }
 262 }
 263
 264 /// A semantically valid [`Invoice`] that hasn't been signed.
 265 pub struct UnsignedInvoice<'a> {
 266         invreq_bytes: &'a Vec<u8>,
 267         invoice: InvoiceContents,
 268 }
 269
 270 impl<'a> UnsignedInvoice<'a> {
 271         /// The public key corresponding to the key needed to sign the invoice.
 272         pub fn signing_pubkey(&self) -> PublicKey {
 273                 self.invoice.fields().signing_pubkey
 274         }
 275
 276         /// Signs the invoice using the given function.
 277         pub fn sign<F, E>(self, sign: F) -> Result<Invoice, SignError<E>>
 278         where
 279                 F: FnOnce(&Message) -> Result<Signature, E>
 280         {
 281                 // Use the invoice_request bytes instead of the invoice_request TLV stream as the latter may
 282                 // have contained unknown TLV records, which are not stored in `InvoiceRequestContents` or
 283                 // `RefundContents`.
 284                 let (_, _, _, invoice_tlv_stream) = self.invoice.as_tlv_stream();
 285                 let invoice_request_bytes = WithoutSignatures(self.invreq_bytes);
 286                 let unsigned_tlv_stream = (invoice_request_bytes, invoice_tlv_stream);
 287
 288                 let mut bytes = Vec::new();
 289                 unsigned_tlv_stream.write(&mut bytes).unwrap();
 290
 291                 let pubkey = self.invoice.fields().signing_pubkey;
 292                 let signature = merkle::sign_message(sign, SIGNATURE_TAG, &bytes, pubkey)?;
 293
 294                 // Append the signature TLV record to the bytes.
 295                 let signature_tlv_stream = SignatureTlvStreamRef {
 296                         signature: Some(&signature),
 297                 };
 298                 signature_tlv_stream.write(&mut bytes).unwrap();
 299
 300                 Ok(Invoice {
 301                         bytes,
 302                         contents: self.invoice,
 303                         signature,
 304                 })
 305         }
 306 }
 307
 308 /// An `Invoice` is a payment request, typically corresponding to an [`Offer`] or a [`Refund`].
 309 ///
 310 /// An invoice may be sent in response to an [`InvoiceRequest`] in the case of an offer or sent
 311 /// directly after scanning a refund. It includes all the information needed to pay a recipient.
 312 ///
 313 /// [`Offer`]: crate::offers::offer::Offer
 314 /// [`Refund`]: crate::offers::refund::Refund
 315 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 316 #[derive(Clone, Debug, PartialEq)]
 317 pub struct Invoice {
 318         bytes: Vec<u8>,
 319         contents: InvoiceContents,
 320         signature: Signature,
 321 }
 322
 323 /// The contents of an [`Invoice`] for responding to either an [`Offer`] or a [`Refund`].
 324 ///
 325 /// [`Offer`]: crate::offers::offer::Offer
 326 /// [`Refund`]: crate::offers::refund::Refund
 327 #[derive(Clone, Debug, PartialEq)]
 328 enum InvoiceContents {
 329         /// Contents for an [`Invoice`] corresponding to an [`Offer`].
 330         ///
 331         /// [`Offer`]: crate::offers::offer::Offer
 332         ForOffer {
 333                 invoice_request: InvoiceRequestContents,
 334                 fields: InvoiceFields,
 335         },
 336         /// Contents for an [`Invoice`] corresponding to a [`Refund`].
 337         ///
 338         /// [`Refund`]: crate::offers::refund::Refund
 339         ForRefund {
 340                 refund: RefundContents,
 341                 fields: InvoiceFields,
 342         },
 343 }
 344
 345 /// Invoice-specific fields for an `invoice` message.
 346 #[derive(Clone, Debug, PartialEq)]
 347 struct InvoiceFields {
 348         payment_paths: Vec<(BlindedPath, BlindedPayInfo)>,
 349         created_at: Duration,
 350         relative_expiry: Option<Duration>,
 351         payment_hash: PaymentHash,
 352         amount_msats: u64,
 353         fallbacks: Option<Vec<FallbackAddress>>,
 354         features: Bolt12InvoiceFeatures,
 355         signing_pubkey: PublicKey,
 356 }
 357
 358 impl Invoice {
 359         /// Paths to the recipient originating from publicly reachable nodes, including information
 360         /// needed for routing payments across them.
 361         ///
 362         /// Blinded paths provide recipient privacy by obfuscating its node id. Note, however, that this
 363         /// privacy is lost if a public node id is used for [`Invoice::signing_pubkey`].
 364         pub fn payment_paths(&self) -> &[(BlindedPath, BlindedPayInfo)] {
 365                 &self.contents.fields().payment_paths[..]
 366         }
 367
 368         /// Duration since the Unix epoch when the invoice was created.
 369         pub fn created_at(&self) -> Duration {
 370                 self.contents.fields().created_at
 371         }
 372
 373         /// Duration since [`Invoice::created_at`] when the invoice has expired and therefore should no
 374         /// longer be paid.
 375         pub fn relative_expiry(&self) -> Duration {
 376                 self.contents.fields().relative_expiry.unwrap_or(DEFAULT_RELATIVE_EXPIRY)
 377         }
 378
 379         /// Whether the invoice has expired.
 380         #[cfg(feature = "std")]
 381         pub fn is_expired(&self) -> bool {
 382                 let absolute_expiry = self.created_at().checked_add(self.relative_expiry());
 383                 match absolute_expiry {
 384                         Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() {
 385                                 Ok(elapsed) => elapsed > seconds_from_epoch,
 386                                 Err(_) => false,
 387                         },
 388                         None => false,
 389                 }
 390         }
 391
 392         /// SHA256 hash of the payment preimage that will be given in return for paying the invoice.
 393         pub fn payment_hash(&self) -> PaymentHash {
 394                 self.contents.fields().payment_hash
 395         }
 396
 397         /// The minimum amount required for a successful payment of the invoice.
 398         pub fn amount_msats(&self) -> u64 {
 399                 self.contents.fields().amount_msats
 400         }
 401
 402         /// Fallback addresses for paying the invoice on-chain, in order of most-preferred to
 403         /// least-preferred.
 404         pub fn fallbacks(&self) -> Vec<Address> {
 405                 let network = match self.network() {
 406                         None => return Vec::new(),
 407                         Some(network) => network,
 408                 };
 409
 410                 let to_valid_address = |address: &FallbackAddress| {
 411                         let version = match WitnessVersion::try_from(address.version) {
 412                                 Ok(version) => version,
 413                                 Err(_) => return None,
 414                         };
 415
 416                         let program = &address.program;
 417                         if program.len() < 2 || program.len() > 40 {
 418                                 return None;
 419                         }
 420
 421                         let address = Address {
 422                                 payload: Payload::WitnessProgram {
 423                                         version,
 424                                         program: address.program.clone(),
 425                                 },
 426                                 network,
 427                         };
 428
 429                         if !address.is_standard() && version == WitnessVersion::V0 {
 430                                 return None;
 431                         }
 432
 433                         Some(address)
 434                 };
 435
 436                 self.contents.fields().fallbacks
 437                         .as_ref()
 438                         .map(|fallbacks| fallbacks.iter().filter_map(to_valid_address).collect())
 439                         .unwrap_or_else(Vec::new)
 440         }
 441
 442         fn network(&self) -> Option<Network> {
 443                 let chain = self.contents.chain();
 444                 if chain == ChainHash::using_genesis_block(Network::Bitcoin) {
 445                         Some(Network::Bitcoin)
 446                 } else if chain == ChainHash::using_genesis_block(Network::Testnet) {
 447                         Some(Network::Testnet)
 448                 } else if chain == ChainHash::using_genesis_block(Network::Signet) {
 449                         Some(Network::Signet)
 450                 } else if chain == ChainHash::using_genesis_block(Network::Regtest) {
 451                         Some(Network::Regtest)
 452                 } else {
 453                         None
 454                 }
 455         }
 456
 457         /// Features pertaining to paying an invoice.
 458         pub fn features(&self) -> &Bolt12InvoiceFeatures {
 459                 &self.contents.fields().features
 460         }
 461
 462         /// The public key corresponding to the key used to sign the invoice.
 463         pub fn signing_pubkey(&self) -> PublicKey {
 464                 self.contents.fields().signing_pubkey
 465         }
 466
 467         /// Signature of the invoice verified using [`Invoice::signing_pubkey`].
 468         pub fn signature(&self) -> Signature {
 469                 self.signature
 470         }
 471
 472         /// Hash that was used for signing the invoice.
 473         pub fn signable_hash(&self) -> [u8; 32] {
 474                 merkle::message_digest(SIGNATURE_TAG, &self.bytes).as_ref().clone()
 475         }
 476
 477         #[cfg(test)]
 478         fn as_tlv_stream(&self) -> FullInvoiceTlvStreamRef {
 479                 let (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream) =
 480                         self.contents.as_tlv_stream();
 481                 let signature_tlv_stream = SignatureTlvStreamRef {
 482                         signature: Some(&self.signature),
 483                 };
 484                 (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
 485                  signature_tlv_stream)
 486         }
 487 }
 488
 489 impl InvoiceContents {
 490         /// Whether the original offer or refund has expired.
 491         #[cfg(feature = "std")]
 492         fn is_offer_or_refund_expired(&self) -> bool {
 493                 match self {
 494                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.offer.is_expired(),
 495                         InvoiceContents::ForRefund { refund, .. } => refund.is_expired(),
 496                 }
 497         }
 498
 499         fn chain(&self) -> ChainHash {
 500                 match self {
 501                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.chain(),
 502                         InvoiceContents::ForRefund { refund, .. } => refund.chain(),
 503                 }
 504         }
 505
 506         fn fields(&self) -> &InvoiceFields {
 507                 match self {
 508                         InvoiceContents::ForOffer { fields, .. } => fields,
 509                         InvoiceContents::ForRefund { fields, .. } => fields,
 510                 }
 511         }
 512
 513         fn fields_mut(&mut self) -> &mut InvoiceFields {
 514                 match self {
 515                         InvoiceContents::ForOffer { fields, .. } => fields,
 516                         InvoiceContents::ForRefund { fields, .. } => fields,
 517                 }
 518         }
 519
 520         fn as_tlv_stream(&self) -> PartialInvoiceTlvStreamRef {
 521                 let (payer, offer, invoice_request) = match self {
 522                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.as_tlv_stream(),
 523                         InvoiceContents::ForRefund { refund, .. } => refund.as_tlv_stream(),
 524                 };
 525                 let invoice = self.fields().as_tlv_stream();
 526
 527                 (payer, offer, invoice_request, invoice)
 528         }
 529 }
 530
 531 impl InvoiceFields {
 532         fn as_tlv_stream(&self) -> InvoiceTlvStreamRef {
 533                 let features = {
 534                         if self.features == Bolt12InvoiceFeatures::empty() { None }
 535                         else { Some(&self.features) }
 536                 };
 537
 538                 InvoiceTlvStreamRef {
 539                         paths: Some(Iterable(self.payment_paths.iter().map(|(path, _)| path))),
 540                         blindedpay: Some(Iterable(self.payment_paths.iter().map(|(_, payinfo)| payinfo))),
 541                         created_at: Some(self.created_at.as_secs()),
 542                         relative_expiry: self.relative_expiry.map(|duration| duration.as_secs() as u32),
 543                         payment_hash: Some(&self.payment_hash),
 544                         amount: Some(self.amount_msats),
 545                         fallbacks: self.fallbacks.as_ref(),
 546                         features,
 547                         node_id: Some(&self.signing_pubkey),
 548                 }
 549         }
 550 }
 551
 552 impl Writeable for Invoice {
 553         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 554                 WithoutLength(&self.bytes).write(writer)
 555         }
 556 }
 557
 558 impl Writeable for InvoiceContents {
 559         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 560                 self.as_tlv_stream().write(writer)
 561         }
 562 }
 563
 564 impl TryFrom<Vec<u8>> for Invoice {
 565         type Error = ParseError;
 566
 567         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 568                 let parsed_invoice = ParsedMessage::<FullInvoiceTlvStream>::try_from(bytes)?;
 569                 Invoice::try_from(parsed_invoice)
 570         }
 571 }
 572
 573 tlv_stream!(InvoiceTlvStream, InvoiceTlvStreamRef, 160..240, {
 574         (160, paths: (Vec<BlindedPath>, WithoutLength, Iterable<'a, BlindedPathIter<'a>, BlindedPath>)),
 575         (162, blindedpay: (Vec<BlindedPayInfo>, WithoutLength, Iterable<'a, BlindedPayInfoIter<'a>, BlindedPayInfo>)),
 576         (164, created_at: (u64, HighZeroBytesDroppedBigSize)),
 577         (166, relative_expiry: (u32, HighZeroBytesDroppedBigSize)),
 578         (168, payment_hash: PaymentHash),
 579         (170, amount: (u64, HighZeroBytesDroppedBigSize)),
 580         (172, fallbacks: (Vec<FallbackAddress>, WithoutLength)),
 581         (174, features: (Bolt12InvoiceFeatures, WithoutLength)),
 582         (176, node_id: PublicKey),
 583 });
 584
 585 type BlindedPathIter<'a> = core::iter::Map<
 586         core::slice::Iter<'a, (BlindedPath, BlindedPayInfo)>,
 587         for<'r> fn(&'r (BlindedPath, BlindedPayInfo)) -> &'r BlindedPath,
 588 >;
 589
 590 type BlindedPayInfoIter<'a> = core::iter::Map<
 591         core::slice::Iter<'a, (BlindedPath, BlindedPayInfo)>,
 592         for<'r> fn(&'r (BlindedPath, BlindedPayInfo)) -> &'r BlindedPayInfo,
 593 >;
 594
 595 /// Information needed to route a payment across a [`BlindedPath`].
 596 #[derive(Clone, Debug, PartialEq)]
 597 pub struct BlindedPayInfo {
 598         /// Base fee charged (in millisatoshi) for the entire blinded path.
 599         pub fee_base_msat: u32,
 600
 601         /// Liquidity fee charged (in millionths of the amount transferred) for the entire blinded path
 602         /// (i.e., 10,000 is 1%).
 603         pub fee_proportional_millionths: u32,
 604
 605         /// Number of blocks subtracted from an incoming HTLC's `cltv_expiry` for the entire blinded
 606         /// path.
 607         pub cltv_expiry_delta: u16,
 608
 609         /// The minimum HTLC value (in millisatoshi) that is acceptable to all channel peers on the
 610         /// blinded path from the introduction node to the recipient, accounting for any fees, i.e., as
 611         /// seen by the recipient.
 612         pub htlc_minimum_msat: u64,
 613
 614         /// The maximum HTLC value (in millisatoshi) that is acceptable to all channel peers on the
 615         /// blinded path from the introduction node to the recipient, accounting for any fees, i.e., as
 616         /// seen by the recipient.
 617         pub htlc_maximum_msat: u64,
 618
 619         /// Features set in `encrypted_data_tlv` for the `encrypted_recipient_data` TLV record in an
 620         /// onion payload.
 621         pub features: BlindedHopFeatures,
 622 }
 623
 624 impl_writeable!(BlindedPayInfo, {
 625         fee_base_msat,
 626         fee_proportional_millionths,
 627         cltv_expiry_delta,
 628         htlc_minimum_msat,
 629         htlc_maximum_msat,
 630         features
 631 });
 632
 633 /// Wire representation for an on-chain fallback address.
 634 #[derive(Clone, Debug, PartialEq)]
 635 pub(super) struct FallbackAddress {
 636         version: u8,
 637         program: Vec<u8>,
 638 }
 639
 640 impl_writeable!(FallbackAddress, { version, program });
 641
 642 type FullInvoiceTlvStream =
 643         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, InvoiceTlvStream, SignatureTlvStream);
 644
 645 #[cfg(test)]
 646 type FullInvoiceTlvStreamRef<'a> = (
 647         PayerTlvStreamRef<'a>,
 648         OfferTlvStreamRef<'a>,
 649         InvoiceRequestTlvStreamRef<'a>,
 650         InvoiceTlvStreamRef<'a>,
 651         SignatureTlvStreamRef<'a>,
 652 );
 653
 654 impl SeekReadable for FullInvoiceTlvStream {
 655         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 656                 let payer = SeekReadable::read(r)?;
 657                 let offer = SeekReadable::read(r)?;
 658                 let invoice_request = SeekReadable::read(r)?;
 659                 let invoice = SeekReadable::read(r)?;
 660                 let signature = SeekReadable::read(r)?;
 661
 662                 Ok((payer, offer, invoice_request, invoice, signature))
 663         }
 664 }
 665
 666 type PartialInvoiceTlvStream =
 667         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, InvoiceTlvStream);
 668
 669 type PartialInvoiceTlvStreamRef<'a> = (
 670         PayerTlvStreamRef<'a>,
 671         OfferTlvStreamRef<'a>,
 672         InvoiceRequestTlvStreamRef<'a>,
 673         InvoiceTlvStreamRef<'a>,
 674 );
 675
 676 impl TryFrom<ParsedMessage<FullInvoiceTlvStream>> for Invoice {
 677         type Error = ParseError;
 678
 679         fn try_from(invoice: ParsedMessage<FullInvoiceTlvStream>) -> Result<Self, Self::Error> {
 680                 let ParsedMessage { bytes, tlv_stream } = invoice;
 681                 let (
 682                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
 683                         SignatureTlvStream { signature },
 684                 ) = tlv_stream;
 685                 let contents = InvoiceContents::try_from(
 686                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream)
 687                 )?;
 688
 689                 let signature = match signature {
 690                         None => return Err(ParseError::InvalidSemantics(SemanticError::MissingSignature)),
 691                         Some(signature) => signature,
 692                 };
 693                 let pubkey = contents.fields().signing_pubkey;
 694                 merkle::verify_signature(&signature, SIGNATURE_TAG, &bytes, pubkey)?;
 695
 696                 Ok(Invoice { bytes, contents, signature })
 697         }
 698 }
 699
 700 impl TryFrom<PartialInvoiceTlvStream> for InvoiceContents {
 701         type Error = SemanticError;
 702
 703         fn try_from(tlv_stream: PartialInvoiceTlvStream) -> Result<Self, Self::Error> {
 704                 let (
 705                         payer_tlv_stream,
 706                         offer_tlv_stream,
 707                         invoice_request_tlv_stream,
 708                         InvoiceTlvStream {
 709                                 paths, blindedpay, created_at, relative_expiry, payment_hash, amount, fallbacks,
 710                                 features, node_id,
 711                         },
 712                 ) = tlv_stream;
 713
 714                 let payment_paths = match (paths, blindedpay) {
 715                         (None, _) => return Err(SemanticError::MissingPaths),
 716                         (_, None) => return Err(SemanticError::InvalidPayInfo),
 717                         (Some(paths), _) if paths.is_empty() => return Err(SemanticError::MissingPaths),
 718                         (Some(paths), Some(blindedpay)) if paths.len() != blindedpay.len() => {
 719                                 return Err(SemanticError::InvalidPayInfo);
 720                         },
 721                         (Some(paths), Some(blindedpay)) => {
 722                                 paths.into_iter().zip(blindedpay.into_iter()).collect::<Vec<_>>()
 723                         },
 724                 };
 725
 726                 let created_at = match created_at {
 727                         None => return Err(SemanticError::MissingCreationTime),
 728                         Some(timestamp) => Duration::from_secs(timestamp),
 729                 };
 730
 731                 let relative_expiry = relative_expiry
 732                         .map(Into::<u64>::into)
 733                         .map(Duration::from_secs);
 734
 735                 let payment_hash = match payment_hash {
 736                         None => return Err(SemanticError::MissingPaymentHash),
 737                         Some(payment_hash) => payment_hash,
 738                 };
 739
 740                 let amount_msats = match amount {
 741                         None => return Err(SemanticError::MissingAmount),
 742                         Some(amount) => amount,
 743                 };
 744
 745                 let features = features.unwrap_or_else(Bolt12InvoiceFeatures::empty);
 746
 747                 let signing_pubkey = match node_id {
 748                         None => return Err(SemanticError::MissingSigningPubkey),
 749                         Some(node_id) => node_id,
 750                 };
 751
 752                 let fields = InvoiceFields {
 753                         payment_paths, created_at, relative_expiry, payment_hash, amount_msats, fallbacks,
 754                         features, signing_pubkey,
 755                 };
 756
 757                 match offer_tlv_stream.node_id {
 758                         Some(expected_signing_pubkey) => {
 759                                 if fields.signing_pubkey != expected_signing_pubkey {
 760                                         return Err(SemanticError::InvalidSigningPubkey);
 761                                 }
 762
 763                                 let invoice_request = InvoiceRequestContents::try_from(
 764                                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 765                                 )?;
 766                                 Ok(InvoiceContents::ForOffer { invoice_request, fields })
 767                         },
 768                         None => {
 769                                 let refund = RefundContents::try_from(
 770                                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 771                                 )?;
 772                                 Ok(InvoiceContents::ForRefund { refund, fields })
 773                         },
 774                 }
 775         }
 776 }
 777
 778 #[cfg(test)]
 779 mod tests {
 780         use super::{DEFAULT_RELATIVE_EXPIRY, BlindedPayInfo, FallbackAddress, FullInvoiceTlvStreamRef, Invoice, InvoiceTlvStreamRef, SIGNATURE_TAG};
 781
 782         use bitcoin::blockdata::script::Script;
 783         use bitcoin::hashes::Hash;
 784         use bitcoin::network::constants::Network;
 785         use bitcoin::secp256k1::{KeyPair, Message, PublicKey, Secp256k1, SecretKey, XOnlyPublicKey, self};
 786         use bitcoin::secp256k1::schnorr::Signature;
 787         use bitcoin::util::address::{Address, Payload, WitnessVersion};
 788         use bitcoin::util::schnorr::TweakedPublicKey;
 789         use core::convert::{Infallible, TryFrom};
 790         use core::time::Duration;
 791         use crate::ln::PaymentHash;
 792         use crate::ln::msgs::DecodeError;
 793         use crate::ln::features::{BlindedHopFeatures, Bolt12InvoiceFeatures};
 794         use crate::offers::invoice_request::InvoiceRequestTlvStreamRef;
 795         use crate::offers::merkle::{SignError, SignatureTlvStreamRef, self};
 796         use crate::offers::offer::{OfferBuilder, OfferTlvStreamRef, Quantity};
 797         use crate::offers::parse::{ParseError, SemanticError};
 798         use crate::offers::payer::PayerTlvStreamRef;
 799         use crate::offers::refund::RefundBuilder;
 800         use crate::onion_message::{BlindedHop, BlindedPath};
 801         use crate::util::ser::{BigSize, Iterable, Writeable};
 802
 803         fn payer_keys() -> KeyPair {
 804                 let secp_ctx = Secp256k1::new();
 805                 KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
 806         }
 807
 808         fn payer_sign(digest: &Message) -> Result<Signature, Infallible> {
 809                 let secp_ctx = Secp256k1::new();
 810                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
 811                 Ok(secp_ctx.sign_schnorr_no_aux_rand(digest, &keys))
 812         }
 813
 814         fn payer_pubkey() -> PublicKey {
 815                 payer_keys().public_key()
 816         }
 817
 818         fn recipient_keys() -> KeyPair {
 819                 let secp_ctx = Secp256k1::new();
 820                 KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[43; 32]).unwrap())
 821         }
 822
 823         fn recipient_sign(digest: &Message) -> Result<Signature, Infallible> {
 824                 let secp_ctx = Secp256k1::new();
 825                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[43; 32]).unwrap());
 826                 Ok(secp_ctx.sign_schnorr_no_aux_rand(digest, &keys))
 827         }
 828
 829         fn recipient_pubkey() -> PublicKey {
 830                 recipient_keys().public_key()
 831         }
 832
 833         fn pubkey(byte: u8) -> PublicKey {
 834                 let secp_ctx = Secp256k1::new();
 835                 PublicKey::from_secret_key(&secp_ctx, &privkey(byte))
 836         }
 837
 838         fn privkey(byte: u8) -> SecretKey {
 839                 SecretKey::from_slice(&[byte; 32]).unwrap()
 840         }
 841
 842         trait ToBytes {
 843                 fn to_bytes(&self) -> Vec<u8>;
 844         }
 845
 846         impl<'a> ToBytes for FullInvoiceTlvStreamRef<'a> {
 847                 fn to_bytes(&self) -> Vec<u8> {
 848                         let mut buffer = Vec::new();
 849                         self.0.write(&mut buffer).unwrap();
 850                         self.1.write(&mut buffer).unwrap();
 851                         self.2.write(&mut buffer).unwrap();
 852                         self.3.write(&mut buffer).unwrap();
 853                         self.4.write(&mut buffer).unwrap();
 854                         buffer
 855                 }
 856         }
 857
 858         fn payment_paths() -> Vec<(BlindedPath, BlindedPayInfo)> {
 859                 let paths = vec![
 860                         BlindedPath {
 861                                 introduction_node_id: pubkey(40),
 862                                 blinding_point: pubkey(41),
 863                                 blinded_hops: vec![
 864                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
 865                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
 866                                 ],
 867                         },
 868                         BlindedPath {
 869                                 introduction_node_id: pubkey(40),
 870                                 blinding_point: pubkey(41),
 871                                 blinded_hops: vec![
 872                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
 873                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
 874                                 ],
 875                         },
 876                 ];
 877
 878                 let payinfo = vec![
 879                         BlindedPayInfo {
 880                                 fee_base_msat: 1,
 881                                 fee_proportional_millionths: 1_000,
 882                                 cltv_expiry_delta: 42,
 883                                 htlc_minimum_msat: 100,
 884                                 htlc_maximum_msat: 1_000_000_000_000,
 885                                 features: BlindedHopFeatures::empty(),
 886                         },
 887                         BlindedPayInfo {
 888                                 fee_base_msat: 1,
 889                                 fee_proportional_millionths: 1_000,
 890                                 cltv_expiry_delta: 42,
 891                                 htlc_minimum_msat: 100,
 892                                 htlc_maximum_msat: 1_000_000_000_000,
 893                                 features: BlindedHopFeatures::empty(),
 894                         },
 895                 ];
 896
 897                 paths.into_iter().zip(payinfo.into_iter()).collect()
 898         }
 899
 900         fn payment_hash() -> PaymentHash {
 901                 PaymentHash([42; 32])
 902         }
 903
 904         fn now() -> Duration {
 905                 std::time::SystemTime::now()
 906                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 907                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH")
 908         }
 909
 910         #[test]
 911         fn builds_invoice_for_offer_with_defaults() {
 912                 let payment_paths = payment_paths();
 913                 let payment_hash = payment_hash();
 914                 let now = now();
 915                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
 916                         .amount_msats(1000)
 917                         .build().unwrap()
 918                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 919                         .build().unwrap()
 920                         .sign(payer_sign).unwrap()
 921                         .respond_with_no_std(payment_paths.clone(), payment_hash, now).unwrap()
 922                         .build().unwrap()
 923                         .sign(recipient_sign).unwrap();
 924
 925                 let mut buffer = Vec::new();
 926                 invoice.write(&mut buffer).unwrap();
 927
 928                 assert_eq!(invoice.bytes, buffer.as_slice());
 929                 assert_eq!(invoice.payment_paths(), payment_paths.as_slice());
 930                 assert_eq!(invoice.created_at(), now);
 931                 assert_eq!(invoice.relative_expiry(), DEFAULT_RELATIVE_EXPIRY);
 932                 #[cfg(feature = "std")]
 933                 assert!(!invoice.is_expired());
 934                 assert_eq!(invoice.payment_hash(), payment_hash);
 935                 assert_eq!(invoice.amount_msats(), 1000);
 936                 assert_eq!(invoice.fallbacks(), vec![]);
 937                 assert_eq!(invoice.features(), &Bolt12InvoiceFeatures::empty());
 938                 assert_eq!(invoice.signing_pubkey(), recipient_pubkey());
 939                 assert!(
 940                         merkle::verify_signature(
 941                                 &invoice.signature, SIGNATURE_TAG, &invoice.bytes, recipient_pubkey()
 942                         ).is_ok()
 943                 );
 944
 945                 let digest = Message::from_slice(&invoice.signable_hash()).unwrap();
 946                 let pubkey = recipient_pubkey().into();
 947                 let secp_ctx = Secp256k1::verification_only();
 948                 assert!(secp_ctx.verify_schnorr(&invoice.signature, &digest, &pubkey).is_ok());
 949
 950                 assert_eq!(
 951                         invoice.as_tlv_stream(),
 952                         (
 953                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
 954                                 OfferTlvStreamRef {
 955                                         chains: None,
 956                                         metadata: None,
 957                                         currency: None,
 958                                         amount: Some(1000),
 959                                         description: Some(&String::from("foo")),
 960                                         features: None,
 961                                         absolute_expiry: None,
 962                                         paths: None,
 963                                         issuer: None,
 964                                         quantity_max: None,
 965                                         node_id: Some(&recipient_pubkey()),
 966                                 },
 967                                 InvoiceRequestTlvStreamRef {
 968                                         chain: None,
 969                                         amount: None,
 970                                         features: None,
 971                                         quantity: None,
 972                                         payer_id: Some(&payer_pubkey()),
 973                                         payer_note: None,
 974                                 },
 975                                 InvoiceTlvStreamRef {
 976                                         paths: Some(Iterable(payment_paths.iter().map(|(path, _)| path))),
 977                                         blindedpay: Some(Iterable(payment_paths.iter().map(|(_, payinfo)| payinfo))),
 978                                         created_at: Some(now.as_secs()),
 979                                         relative_expiry: None,
 980                                         payment_hash: Some(&payment_hash),
 981                                         amount: Some(1000),
 982                                         fallbacks: None,
 983                                         features: None,
 984                                         node_id: Some(&recipient_pubkey()),
 985                                 },
 986                                 SignatureTlvStreamRef { signature: Some(&invoice.signature()) },
 987                         ),
 988                 );
 989
 990                 if let Err(e) = Invoice::try_from(buffer) {
 991                         panic!("error parsing invoice: {:?}", e);
 992                 }
 993         }
 994
 995         #[test]
 996         fn builds_invoice_for_refund_with_defaults() {
 997                 let payment_paths = payment_paths();
 998                 let payment_hash = payment_hash();
 999                 let now = now();
1000                 let invoice = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
1001                         .build().unwrap()
1002                         .respond_with_no_std(payment_paths.clone(), payment_hash, recipient_pubkey(), now)
1003                         .unwrap()
1004                         .build().unwrap()
1005                         .sign(recipient_sign).unwrap();
1006
1007                 let mut buffer = Vec::new();
1008                 invoice.write(&mut buffer).unwrap();
1009
1010                 assert_eq!(invoice.bytes, buffer.as_slice());
1011                 assert_eq!(invoice.payment_paths(), payment_paths.as_slice());
1012                 assert_eq!(invoice.created_at(), now);
1013                 assert_eq!(invoice.relative_expiry(), DEFAULT_RELATIVE_EXPIRY);
1014                 #[cfg(feature = "std")]
1015                 assert!(!invoice.is_expired());
1016                 assert_eq!(invoice.payment_hash(), payment_hash);
1017                 assert_eq!(invoice.amount_msats(), 1000);
1018                 assert_eq!(invoice.fallbacks(), vec![]);
1019                 assert_eq!(invoice.features(), &Bolt12InvoiceFeatures::empty());
1020                 assert_eq!(invoice.signing_pubkey(), recipient_pubkey());
1021                 assert!(
1022                         merkle::verify_signature(
1023                                 &invoice.signature, SIGNATURE_TAG, &invoice.bytes, recipient_pubkey()
1024                         ).is_ok()
1025                 );
1026
1027                 assert_eq!(
1028                         invoice.as_tlv_stream(),
1029                         (
1030                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
1031                                 OfferTlvStreamRef {
1032                                         chains: None,
1033                                         metadata: None,
1034                                         currency: None,
1035                                         amount: None,
1036                                         description: Some(&String::from("foo")),
1037                                         features: None,
1038                                         absolute_expiry: None,
1039                                         paths: None,
1040                                         issuer: None,
1041                                         quantity_max: None,
1042                                         node_id: None,
1043                                 },
1044                                 InvoiceRequestTlvStreamRef {
1045                                         chain: None,
1046                                         amount: Some(1000),
1047                                         features: None,
1048                                         quantity: None,
1049                                         payer_id: Some(&payer_pubkey()),
1050                                         payer_note: None,
1051                                 },
1052                                 InvoiceTlvStreamRef {
1053                                         paths: Some(Iterable(payment_paths.iter().map(|(path, _)| path))),
1054                                         blindedpay: Some(Iterable(payment_paths.iter().map(|(_, payinfo)| payinfo))),
1055                                         created_at: Some(now.as_secs()),
1056                                         relative_expiry: None,
1057                                         payment_hash: Some(&payment_hash),
1058                                         amount: Some(1000),
1059                                         fallbacks: None,
1060                                         features: None,
1061                                         node_id: Some(&recipient_pubkey()),
1062                                 },
1063                                 SignatureTlvStreamRef { signature: Some(&invoice.signature()) },
1064                         ),
1065                 );
1066
1067                 if let Err(e) = Invoice::try_from(buffer) {
1068                         panic!("error parsing invoice: {:?}", e);
1069                 }
1070         }
1071
1072         #[cfg(feature = "std")]
1073         #[test]
1074         fn builds_invoice_from_offer_with_expiration() {
1075                 let future_expiry = Duration::from_secs(u64::max_value());
1076                 let past_expiry = Duration::from_secs(0);
1077
1078                 if let Err(e) = OfferBuilder::new("foo".into(), recipient_pubkey())
1079                         .amount_msats(1000)
1080                         .absolute_expiry(future_expiry)
1081                         .build().unwrap()
1082                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1083                         .build().unwrap()
1084                         .sign(payer_sign).unwrap()
1085                         .respond_with(payment_paths(), payment_hash())
1086                         .unwrap()
1087                         .build()
1088                 {
1089                         panic!("error building invoice: {:?}", e);
1090                 }
1091
1092                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1093                         .amount_msats(1000)
1094                         .absolute_expiry(past_expiry)
1095                         .build().unwrap()
1096                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1097                         .build_unchecked()
1098                         .sign(payer_sign).unwrap()
1099                         .respond_with(payment_paths(), payment_hash())
1100                         .unwrap()
1101                         .build()
1102                 {
1103                         Ok(_) => panic!("expected error"),
1104                         Err(e) => assert_eq!(e, SemanticError::AlreadyExpired),
1105                 }
1106         }
1107
1108         #[cfg(feature = "std")]
1109         #[test]
1110         fn builds_invoice_from_refund_with_expiration() {
1111                 let future_expiry = Duration::from_secs(u64::max_value());
1112                 let past_expiry = Duration::from_secs(0);
1113
1114                 if let Err(e) = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
1115                         .absolute_expiry(future_expiry)
1116                         .build().unwrap()
1117                         .respond_with(payment_paths(), payment_hash(), recipient_pubkey())
1118                         .unwrap()
1119                         .build()
1120                 {
1121                         panic!("error building invoice: {:?}", e);
1122                 }
1123
1124                 match RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
1125                         .absolute_expiry(past_expiry)
1126                         .build().unwrap()
1127                         .respond_with(payment_paths(), payment_hash(), recipient_pubkey())
1128                         .unwrap()
1129                         .build()
1130                 {
1131                         Ok(_) => panic!("expected error"),
1132                         Err(e) => assert_eq!(e, SemanticError::AlreadyExpired),
1133                 }
1134         }
1135
1136         #[test]
1137         fn builds_invoice_with_relative_expiry() {
1138                 let now = now();
1139                 let one_hour = Duration::from_secs(3600);
1140
1141                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1142                         .amount_msats(1000)
1143                         .build().unwrap()
1144                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1145                         .build().unwrap()
1146                         .sign(payer_sign).unwrap()
1147                         .respond_with_no_std(payment_paths(), payment_hash(), now).unwrap()
1148                         .relative_expiry(one_hour.as_secs() as u32)
1149                         .build().unwrap()
1150                         .sign(recipient_sign).unwrap();
1151                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1152                 #[cfg(feature = "std")]
1153                 assert!(!invoice.is_expired());
1154                 assert_eq!(invoice.relative_expiry(), one_hour);
1155                 assert_eq!(tlv_stream.relative_expiry, Some(one_hour.as_secs() as u32));
1156
1157                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1158                         .amount_msats(1000)
1159                         .build().unwrap()
1160                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1161                         .build().unwrap()
1162                         .sign(payer_sign).unwrap()
1163                         .respond_with_no_std(payment_paths(), payment_hash(), now - one_hour).unwrap()
1164                         .relative_expiry(one_hour.as_secs() as u32 - 1)
1165                         .build().unwrap()
1166                         .sign(recipient_sign).unwrap();
1167                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1168                 #[cfg(feature = "std")]
1169                 assert!(invoice.is_expired());
1170                 assert_eq!(invoice.relative_expiry(), one_hour - Duration::from_secs(1));
1171                 assert_eq!(tlv_stream.relative_expiry, Some(one_hour.as_secs() as u32 - 1));
1172         }
1173
1174         #[test]
1175         fn builds_invoice_with_amount_from_request() {
1176                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1177                         .amount_msats(1000)
1178                         .build().unwrap()
1179                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1180                         .amount_msats(1001).unwrap()
1181                         .build().unwrap()
1182                         .sign(payer_sign).unwrap()
1183                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1184                         .build().unwrap()
1185                         .sign(recipient_sign).unwrap();
1186                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1187                 assert_eq!(invoice.amount_msats(), 1001);
1188                 assert_eq!(tlv_stream.amount, Some(1001));
1189         }
1190
1191         #[test]
1192         fn builds_invoice_with_quantity_from_request() {
1193                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1194                         .amount_msats(1000)
1195                         .supported_quantity(Quantity::Unbounded)
1196                         .build().unwrap()
1197                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1198                         .quantity(2).unwrap()
1199                         .build().unwrap()
1200                         .sign(payer_sign).unwrap()
1201                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1202                         .build().unwrap()
1203                         .sign(recipient_sign).unwrap();
1204                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1205                 assert_eq!(invoice.amount_msats(), 2000);
1206                 assert_eq!(tlv_stream.amount, Some(2000));
1207
1208                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1209                         .amount_msats(1000)
1210                         .supported_quantity(Quantity::Unbounded)
1211                         .build().unwrap()
1212                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1213                         .quantity(u64::max_value()).unwrap()
1214                         .build_unchecked()
1215                         .sign(payer_sign).unwrap()
1216                         .respond_with_no_std(payment_paths(), payment_hash(), now())
1217                 {
1218                         Ok(_) => panic!("expected error"),
1219                         Err(e) => assert_eq!(e, SemanticError::InvalidAmount),
1220                 }
1221         }
1222
1223         #[test]
1224         fn builds_invoice_with_fallback_address() {
1225                 let script = Script::new();
1226                 let pubkey = bitcoin::util::key::PublicKey::new(recipient_pubkey());
1227                 let x_only_pubkey = XOnlyPublicKey::from_keypair(&recipient_keys()).0;
1228                 let tweaked_pubkey = TweakedPublicKey::dangerous_assume_tweaked(x_only_pubkey);
1229
1230                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1231                         .amount_msats(1000)
1232                         .build().unwrap()
1233                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1234                         .build().unwrap()
1235                         .sign(payer_sign).unwrap()
1236                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1237                         .fallback_v0_p2wsh(&script.wscript_hash())
1238                         .fallback_v0_p2wpkh(&pubkey.wpubkey_hash().unwrap())
1239                         .fallback_v1_p2tr_tweaked(&tweaked_pubkey)
1240                         .build().unwrap()
1241                         .sign(recipient_sign).unwrap();
1242                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1243                 assert_eq!(
1244                         invoice.fallbacks(),
1245                         vec![
1246                                 Address::p2wsh(&script, Network::Bitcoin),
1247                                 Address::p2wpkh(&pubkey, Network::Bitcoin).unwrap(),
1248                                 Address::p2tr_tweaked(tweaked_pubkey, Network::Bitcoin),
1249                         ],
1250                 );
1251                 assert_eq!(
1252                         tlv_stream.fallbacks,
1253                         Some(&vec![
1254                                 FallbackAddress {
1255                                         version: WitnessVersion::V0.to_num(),
1256                                         program: Vec::from(&script.wscript_hash().into_inner()[..]),
1257                                 },
1258                                 FallbackAddress {
1259                                         version: WitnessVersion::V0.to_num(),
1260                                         program: Vec::from(&pubkey.wpubkey_hash().unwrap().into_inner()[..]),
1261                                 },
1262                                 FallbackAddress {
1263                                         version: WitnessVersion::V1.to_num(),
1264                                         program: Vec::from(&tweaked_pubkey.serialize()[..]),
1265                                 },
1266                         ])
1267                 );
1268         }
1269
1270         #[test]
1271         fn builds_invoice_with_allow_mpp() {
1272                 let mut features = Bolt12InvoiceFeatures::empty();
1273                 features.set_basic_mpp_optional();
1274
1275                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1276                         .amount_msats(1000)
1277                         .build().unwrap()
1278                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1279                         .build().unwrap()
1280                         .sign(payer_sign).unwrap()
1281                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1282                         .allow_mpp()
1283                         .build().unwrap()
1284                         .sign(recipient_sign).unwrap();
1285                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1286                 assert_eq!(invoice.features(), &features);
1287                 assert_eq!(tlv_stream.features, Some(&features));
1288         }
1289
1290         #[test]
1291         fn fails_signing_invoice() {
1292                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1293                         .amount_msats(1000)
1294                         .build().unwrap()
1295                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1296                         .build().unwrap()
1297                         .sign(payer_sign).unwrap()
1298                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1299                         .build().unwrap()
1300                         .sign(|_| Err(()))
1301                 {
1302                         Ok(_) => panic!("expected error"),
1303                         Err(e) => assert_eq!(e, SignError::Signing(())),
1304                 }
1305
1306                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1307                         .amount_msats(1000)
1308                         .build().unwrap()
1309                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1310                         .build().unwrap()
1311                         .sign(payer_sign).unwrap()
1312                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1313                         .build().unwrap()
1314                         .sign(payer_sign)
1315                 {
1316                         Ok(_) => panic!("expected error"),
1317                         Err(e) => assert_eq!(e, SignError::Verification(secp256k1::Error::InvalidSignature)),
1318                 }
1319         }
1320
1321         #[test]
1322         fn parses_invoice_with_payment_paths() {
1323                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1324                         .amount_msats(1000)
1325                         .build().unwrap()
1326                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1327                         .build().unwrap()
1328                         .sign(payer_sign).unwrap()
1329                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1330                         .build().unwrap()
1331                         .sign(recipient_sign).unwrap();
1332
1333                 let mut buffer = Vec::new();
1334                 invoice.write(&mut buffer).unwrap();
1335
1336                 if let Err(e) = Invoice::try_from(buffer) {
1337                         panic!("error parsing invoice: {:?}", e);
1338                 }
1339
1340                 let mut tlv_stream = invoice.as_tlv_stream();
1341                 tlv_stream.3.paths = None;
1342
1343                 match Invoice::try_from(tlv_stream.to_bytes()) {
1344                         Ok(_) => panic!("expected error"),
1345                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPaths)),
1346                 }
1347
1348                 let mut tlv_stream = invoice.as_tlv_stream();
1349                 tlv_stream.3.blindedpay = None;
1350
1351                 match Invoice::try_from(tlv_stream.to_bytes()) {
1352                         Ok(_) => panic!("expected error"),
1353                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::InvalidPayInfo)),
1354                 }
1355
1356                 let empty_payment_paths = vec![];
1357                 let mut tlv_stream = invoice.as_tlv_stream();
1358                 tlv_stream.3.paths = Some(Iterable(empty_payment_paths.iter().map(|(path, _)| path)));
1359
1360                 match Invoice::try_from(tlv_stream.to_bytes()) {
1361                         Ok(_) => panic!("expected error"),
1362                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPaths)),
1363                 }
1364
1365                 let mut payment_paths = payment_paths();
1366                 payment_paths.pop();
1367                 let mut tlv_stream = invoice.as_tlv_stream();
1368                 tlv_stream.3.blindedpay = Some(Iterable(payment_paths.iter().map(|(_, payinfo)| payinfo)));
1369
1370                 match Invoice::try_from(tlv_stream.to_bytes()) {
1371                         Ok(_) => panic!("expected error"),
1372                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::InvalidPayInfo)),
1373                 }
1374         }
1375
1376         #[test]
1377         fn parses_invoice_with_created_at() {
1378                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1379                         .amount_msats(1000)
1380                         .build().unwrap()
1381                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1382                         .build().unwrap()
1383                         .sign(payer_sign).unwrap()
1384                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1385                         .build().unwrap()
1386                         .sign(recipient_sign).unwrap();
1387
1388                 let mut buffer = Vec::new();
1389                 invoice.write(&mut buffer).unwrap();
1390
1391                 if let Err(e) = Invoice::try_from(buffer) {
1392                         panic!("error parsing invoice: {:?}", e);
1393                 }
1394
1395                 let mut tlv_stream = invoice.as_tlv_stream();
1396                 tlv_stream.3.created_at = None;
1397
1398                 match Invoice::try_from(tlv_stream.to_bytes()) {
1399                         Ok(_) => panic!("expected error"),
1400                         Err(e) => {
1401                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingCreationTime));
1402                         },
1403                 }
1404         }
1405
1406         #[test]
1407         fn parses_invoice_with_relative_expiry() {
1408                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1409                         .amount_msats(1000)
1410                         .build().unwrap()
1411                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1412                         .build().unwrap()
1413                         .sign(payer_sign).unwrap()
1414                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1415                         .relative_expiry(3600)
1416                         .build().unwrap()
1417                         .sign(recipient_sign).unwrap();
1418
1419                 let mut buffer = Vec::new();
1420                 invoice.write(&mut buffer).unwrap();
1421
1422                 match Invoice::try_from(buffer) {
1423                         Ok(invoice) => assert_eq!(invoice.relative_expiry(), Duration::from_secs(3600)),
1424                         Err(e) => panic!("error parsing invoice: {:?}", e),
1425                 }
1426         }
1427
1428         #[test]
1429         fn parses_invoice_with_payment_hash() {
1430                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1431                         .amount_msats(1000)
1432                         .build().unwrap()
1433                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1434                         .build().unwrap()
1435                         .sign(payer_sign).unwrap()
1436                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1437                         .build().unwrap()
1438                         .sign(recipient_sign).unwrap();
1439
1440                 let mut buffer = Vec::new();
1441                 invoice.write(&mut buffer).unwrap();
1442
1443                 if let Err(e) = Invoice::try_from(buffer) {
1444                         panic!("error parsing invoice: {:?}", e);
1445                 }
1446
1447                 let mut tlv_stream = invoice.as_tlv_stream();
1448                 tlv_stream.3.payment_hash = None;
1449
1450                 match Invoice::try_from(tlv_stream.to_bytes()) {
1451                         Ok(_) => panic!("expected error"),
1452                         Err(e) => {
1453                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPaymentHash));
1454                         },
1455                 }
1456         }
1457
1458         #[test]
1459         fn parses_invoice_with_amount() {
1460                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1461                         .amount_msats(1000)
1462                         .build().unwrap()
1463                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1464                         .build().unwrap()
1465                         .sign(payer_sign).unwrap()
1466                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1467                         .build().unwrap()
1468                         .sign(recipient_sign).unwrap();
1469
1470                 let mut buffer = Vec::new();
1471                 invoice.write(&mut buffer).unwrap();
1472
1473                 if let Err(e) = Invoice::try_from(buffer) {
1474                         panic!("error parsing invoice: {:?}", e);
1475                 }
1476
1477                 let mut tlv_stream = invoice.as_tlv_stream();
1478                 tlv_stream.3.amount = None;
1479
1480                 match Invoice::try_from(tlv_stream.to_bytes()) {
1481                         Ok(_) => panic!("expected error"),
1482                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingAmount)),
1483                 }
1484         }
1485
1486         #[test]
1487         fn parses_invoice_with_allow_mpp() {
1488                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1489                         .amount_msats(1000)
1490                         .build().unwrap()
1491                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1492                         .build().unwrap()
1493                         .sign(payer_sign).unwrap()
1494                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1495                         .allow_mpp()
1496                         .build().unwrap()
1497                         .sign(recipient_sign).unwrap();
1498
1499                 let mut buffer = Vec::new();
1500                 invoice.write(&mut buffer).unwrap();
1501
1502                 match Invoice::try_from(buffer) {
1503                         Ok(invoice) => {
1504                                 let mut features = Bolt12InvoiceFeatures::empty();
1505                                 features.set_basic_mpp_optional();
1506                                 assert_eq!(invoice.features(), &features);
1507                         },
1508                         Err(e) => panic!("error parsing invoice: {:?}", e),
1509                 }
1510         }
1511
1512         #[test]
1513         fn parses_invoice_with_fallback_address() {
1514                 let script = Script::new();
1515                 let pubkey = bitcoin::util::key::PublicKey::new(recipient_pubkey());
1516                 let x_only_pubkey = XOnlyPublicKey::from_keypair(&recipient_keys()).0;
1517                 let tweaked_pubkey = TweakedPublicKey::dangerous_assume_tweaked(x_only_pubkey);
1518
1519                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1520                         .amount_msats(1000)
1521                         .build().unwrap();
1522                 let invoice_request = offer
1523                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1524                         .build().unwrap()
1525                         .sign(payer_sign).unwrap();
1526                 let mut unsigned_invoice = invoice_request
1527                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1528                         .fallback_v0_p2wsh(&script.wscript_hash())
1529                         .fallback_v0_p2wpkh(&pubkey.wpubkey_hash().unwrap())
1530                         .fallback_v1_p2tr_tweaked(&tweaked_pubkey)
1531                         .build().unwrap();
1532
1533                 // Only standard addresses will be included.
1534                 let fallbacks = unsigned_invoice.invoice.fields_mut().fallbacks.as_mut().unwrap();
1535                 // Non-standard addresses
1536                 fallbacks.push(FallbackAddress { version: 1, program: vec![0u8; 41] });
1537                 fallbacks.push(FallbackAddress { version: 2, program: vec![0u8; 1] });
1538                 fallbacks.push(FallbackAddress { version: 17, program: vec![0u8; 40] });
1539                 // Standard address
1540                 fallbacks.push(FallbackAddress { version: 1, program: vec![0u8; 33] });
1541                 fallbacks.push(FallbackAddress { version: 2, program: vec![0u8; 40] });
1542
1543                 let invoice = unsigned_invoice.sign(recipient_sign).unwrap();
1544                 let mut buffer = Vec::new();
1545                 invoice.write(&mut buffer).unwrap();
1546
1547                 match Invoice::try_from(buffer) {
1548                         Ok(invoice) => {
1549                                 assert_eq!(
1550                                         invoice.fallbacks(),
1551                                         vec![
1552                                                 Address::p2wsh(&script, Network::Bitcoin),
1553                                                 Address::p2wpkh(&pubkey, Network::Bitcoin).unwrap(),
1554                                                 Address::p2tr_tweaked(tweaked_pubkey, Network::Bitcoin),
1555                                                 Address {
1556                                                         payload: Payload::WitnessProgram {
1557                                                                 version: WitnessVersion::V1,
1558                                                                 program: vec![0u8; 33],
1559                                                         },
1560                                                         network: Network::Bitcoin,
1561                                                 },
1562                                                 Address {
1563                                                         payload: Payload::WitnessProgram {
1564                                                                 version: WitnessVersion::V2,
1565                                                                 program: vec![0u8; 40],
1566                                                         },
1567                                                         network: Network::Bitcoin,
1568                                                 },
1569                                         ],
1570                                 );
1571                         },
1572                         Err(e) => panic!("error parsing invoice: {:?}", e),
1573                 }
1574         }
1575
1576         #[test]
1577         fn parses_invoice_with_node_id() {
1578                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1579                         .amount_msats(1000)
1580                         .build().unwrap()
1581                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1582                         .build().unwrap()
1583                         .sign(payer_sign).unwrap()
1584                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1585                         .build().unwrap()
1586                         .sign(recipient_sign).unwrap();
1587
1588                 let mut buffer = Vec::new();
1589                 invoice.write(&mut buffer).unwrap();
1590
1591                 if let Err(e) = Invoice::try_from(buffer) {
1592                         panic!("error parsing invoice: {:?}", e);
1593                 }
1594
1595                 let mut tlv_stream = invoice.as_tlv_stream();
1596                 tlv_stream.3.node_id = None;
1597
1598                 match Invoice::try_from(tlv_stream.to_bytes()) {
1599                         Ok(_) => panic!("expected error"),
1600                         Err(e) => {
1601                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingSigningPubkey));
1602                         },
1603                 }
1604
1605                 let invalid_pubkey = payer_pubkey();
1606                 let mut tlv_stream = invoice.as_tlv_stream();
1607                 tlv_stream.3.node_id = Some(&invalid_pubkey);
1608
1609                 match Invoice::try_from(tlv_stream.to_bytes()) {
1610                         Ok(_) => panic!("expected error"),
1611                         Err(e) => {
1612                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::InvalidSigningPubkey));
1613                         },
1614                 }
1615         }
1616
1617         #[test]
1618         fn fails_parsing_invoice_without_signature() {
1619                 let mut buffer = Vec::new();
1620                 OfferBuilder::new("foo".into(), recipient_pubkey())
1621                         .amount_msats(1000)
1622                         .build().unwrap()
1623                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1624                         .build().unwrap()
1625                         .sign(payer_sign).unwrap()
1626                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1627                         .build().unwrap()
1628                         .invoice
1629                         .write(&mut buffer).unwrap();
1630
1631                 match Invoice::try_from(buffer) {
1632                         Ok(_) => panic!("expected error"),
1633                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingSignature)),
1634                 }
1635         }
1636
1637         #[test]
1638         fn fails_parsing_invoice_with_invalid_signature() {
1639                 let mut invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1640                         .amount_msats(1000)
1641                         .build().unwrap()
1642                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1643                         .build().unwrap()
1644                         .sign(payer_sign).unwrap()
1645                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1646                         .build().unwrap()
1647                         .sign(recipient_sign).unwrap();
1648                 let last_signature_byte = invoice.bytes.last_mut().unwrap();
1649                 *last_signature_byte = last_signature_byte.wrapping_add(1);
1650
1651                 let mut buffer = Vec::new();
1652                 invoice.write(&mut buffer).unwrap();
1653
1654                 match Invoice::try_from(buffer) {
1655                         Ok(_) => panic!("expected error"),
1656                         Err(e) => {
1657                                 assert_eq!(e, ParseError::InvalidSignature(secp256k1::Error::InvalidSignature));
1658                         },
1659                 }
1660         }
1661
1662         #[test]
1663         fn fails_parsing_invoice_with_extra_tlv_records() {
1664                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1665                         .amount_msats(1000)
1666                         .build().unwrap()
1667                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1668                         .build().unwrap()
1669                         .sign(payer_sign).unwrap()
1670                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1671                         .build().unwrap()
1672                         .sign(recipient_sign).unwrap();
1673
1674                 let mut encoded_invoice = Vec::new();
1675                 invoice.write(&mut encoded_invoice).unwrap();
1676                 BigSize(1002).write(&mut encoded_invoice).unwrap();
1677                 BigSize(32).write(&mut encoded_invoice).unwrap();
1678                 [42u8; 32].write(&mut encoded_invoice).unwrap();
1679
1680                 match Invoice::try_from(encoded_invoice) {
1681                         Ok(_) => panic!("expected error"),
1682                         Err(e) => assert_eq!(e, ParseError::Decode(DecodeError::InvalidValue)),
1683                 }
1684         }
1685 }