_ 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 use bitcoin::blockdata::constants::ChainHash;
  13 use bitcoin::hash_types::{WPubkeyHash, WScriptHash};
  14 use bitcoin::hashes::Hash;
  15 use bitcoin::network::constants::Network;
  16 use bitcoin::secp256k1::{Message, PublicKey};
  17 use bitcoin::secp256k1::schnorr::Signature;
  18 use bitcoin::util::address::{Address, Payload, WitnessVersion};
  19 use bitcoin::util::schnorr::TweakedPublicKey;
  20 use core::convert::TryFrom;
  21 use core::time::Duration;
  22 use crate::io;
  23 use crate::ln::PaymentHash;
  24 use crate::ln::features::{BlindedHopFeatures, Bolt12InvoiceFeatures};
  25 use crate::ln::msgs::DecodeError;
  26 use crate::offers::invoice_request::{InvoiceRequest, InvoiceRequestContents, InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef};
  27 use crate::offers::merkle::{SignError, SignatureTlvStream, SignatureTlvStreamRef, WithoutSignatures, self};
  28 use crate::offers::offer::{Amount, OfferTlvStream, OfferTlvStreamRef};
  29 use crate::offers::parse::{ParseError, ParsedMessage, SemanticError};
  30 use crate::offers::payer::{PayerTlvStream, PayerTlvStreamRef};
  31 use crate::offers::refund::{Refund, RefundContents};
  32 use crate::onion_message::BlindedPath;
  33 use crate::util::ser::{HighZeroBytesDroppedBigSize, Iterable, SeekReadable, WithoutLength, Writeable, Writer};
  34
  35 use crate::prelude::*;
  36
  37 #[cfg(feature = "std")]
  38 use std::time::SystemTime;
  39
  40 const DEFAULT_RELATIVE_EXPIRY: Duration = Duration::from_secs(7200);
  41
  42 const SIGNATURE_TAG: &'static str = concat!("lightning", "invoice", "signature");
  43
  44 /// Builds an [`Invoice`] from either:
  45 /// - an [`InvoiceRequest`] for the "offer to be paid" flow or
  46 /// - a [`Refund`] for the "offer for money" flow.
  47 ///
  48 /// See [module-level documentation] for usage.
  49 ///
  50 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
  51 /// [`Refund`]: crate::offers::refund::Refund
  52 /// [module-level documentation]: self
  53 pub struct InvoiceBuilder<'a> {
  54         invreq_bytes: &'a Vec<u8>,
  55         invoice: InvoiceContents,
  56 }
  57
  58 impl<'a> InvoiceBuilder<'a> {
  59         pub(super) fn for_offer(
  60                 invoice_request: &'a InvoiceRequest, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>,
  61                 created_at: Duration, payment_hash: PaymentHash
  62         ) -> Result<Self, SemanticError> {
  63                 let amount_msats = match invoice_request.amount_msats() {
  64                         Some(amount_msats) => amount_msats,
  65                         None => match invoice_request.contents.offer.amount() {
  66                                 Some(Amount::Bitcoin { amount_msats }) => {
  67                                         amount_msats * invoice_request.quantity().unwrap_or(1)
  68                                 },
  69                                 Some(Amount::Currency { .. }) => return Err(SemanticError::UnsupportedCurrency),
  70                                 None => return Err(SemanticError::MissingAmount),
  71                         },
  72                 };
  73
  74                 let contents = InvoiceContents::ForOffer {
  75                         invoice_request: invoice_request.contents.clone(),
  76                         fields: InvoiceFields {
  77                                 payment_paths, created_at, relative_expiry: None, payment_hash, amount_msats,
  78                                 fallbacks: None, features: Bolt12InvoiceFeatures::empty(),
  79                                 signing_pubkey: invoice_request.contents.offer.signing_pubkey(),
  80                         },
  81                 };
  82
  83                 Self::new(&invoice_request.bytes, contents)
  84         }
  85
  86         pub(super) fn for_refund(
  87                 refund: &'a Refund, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>, created_at: Duration,
  88                 payment_hash: PaymentHash, signing_pubkey: PublicKey
  89         ) -> Result<Self, SemanticError> {
  90                 let contents = InvoiceContents::ForRefund {
  91                         refund: refund.contents.clone(),
  92                         fields: InvoiceFields {
  93                                 payment_paths, created_at, relative_expiry: None, payment_hash,
  94                                 amount_msats: refund.amount_msats(), fallbacks: None,
  95                                 features: Bolt12InvoiceFeatures::empty(), signing_pubkey,
  96                         },
  97                 };
  98
  99                 Self::new(&refund.bytes, contents)
 100         }
 101
 102         fn new(invreq_bytes: &'a Vec<u8>, contents: InvoiceContents) -> Result<Self, SemanticError> {
 103                 if contents.fields().payment_paths.is_empty() {
 104                         return Err(SemanticError::MissingPaths);
 105                 }
 106
 107                 Ok(Self { invreq_bytes, invoice: contents })
 108         }
 109
 110         /// Sets the [`Invoice::relative_expiry`] as seconds since [`Invoice::created_at`]. Any expiry
 111         /// that has already passed is valid and can be checked for using [`Invoice::is_expired`].
 112         ///
 113         /// Successive calls to this method will override the previous setting.
 114         pub fn relative_expiry(mut self, relative_expiry_secs: u32) -> Self {
 115                 let relative_expiry = Duration::from_secs(relative_expiry_secs as u64);
 116                 self.invoice.fields_mut().relative_expiry = Some(relative_expiry);
 117                 self
 118         }
 119
 120         /// Adds a P2WSH address to [`Invoice::fallbacks`].
 121         ///
 122         /// Successive calls to this method will add another address. Caller is responsible for not
 123         /// adding duplicate addresses and only calling if capable of receiving to P2WSH addresses.
 124         pub fn fallback_v0_p2wsh(mut self, script_hash: &WScriptHash) -> Self {
 125                 let address = FallbackAddress {
 126                         version: WitnessVersion::V0.to_num(),
 127                         program: Vec::from(&script_hash.into_inner()[..]),
 128                 };
 129                 self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
 130                 self
 131         }
 132
 133         /// Adds a P2WPKH address to [`Invoice::fallbacks`].
 134         ///
 135         /// Successive calls to this method will add another address. Caller is responsible for not
 136         /// adding duplicate addresses and only calling if capable of receiving to P2WPKH addresses.
 137         pub fn fallback_v0_p2wpkh(mut self, pubkey_hash: &WPubkeyHash) -> Self {
 138                 let address = FallbackAddress {
 139                         version: WitnessVersion::V0.to_num(),
 140                         program: Vec::from(&pubkey_hash.into_inner()[..]),
 141                 };
 142                 self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
 143                 self
 144         }
 145
 146         /// Adds a P2TR address to [`Invoice::fallbacks`].
 147         ///
 148         /// Successive calls to this method will add another address. Caller is responsible for not
 149         /// adding duplicate addresses and only calling if capable of receiving to P2TR addresses.
 150         pub fn fallback_v1_p2tr_tweaked(mut self, output_key: &TweakedPublicKey) -> Self {
 151                 let address = FallbackAddress {
 152                         version: WitnessVersion::V1.to_num(),
 153                         program: Vec::from(&output_key.serialize()[..]),
 154                 };
 155                 self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
 156                 self
 157         }
 158
 159         /// Sets [`Invoice::features`] to indicate MPP may be used. Otherwise, MPP is disallowed.
 160         pub fn allow_mpp(mut self) -> Self {
 161                 self.invoice.fields_mut().features.set_basic_mpp_optional();
 162                 self
 163         }
 164
 165         /// Builds an unsigned [`Invoice`] after checking for valid semantics. It can be signed by
 166         /// [`UnsignedInvoice::sign`].
 167         pub fn build(self) -> Result<UnsignedInvoice<'a>, SemanticError> {
 168                 #[cfg(feature = "std")] {
 169                         if self.invoice.is_offer_or_refund_expired() {
 170                                 return Err(SemanticError::AlreadyExpired);
 171                         }
 172                 }
 173
 174                 let InvoiceBuilder { invreq_bytes, invoice } = self;
 175                 Ok(UnsignedInvoice { invreq_bytes, invoice })
 176         }
 177 }
 178
 179 /// A semantically valid [`Invoice`] that hasn't been signed.
 180 pub struct UnsignedInvoice<'a> {
 181         invreq_bytes: &'a Vec<u8>,
 182         invoice: InvoiceContents,
 183 }
 184
 185 impl<'a> UnsignedInvoice<'a> {
 186         /// Signs the invoice using the given function.
 187         pub fn sign<F, E>(self, sign: F) -> Result<Invoice, SignError<E>>
 188         where
 189                 F: FnOnce(&Message) -> Result<Signature, E>
 190         {
 191                 // Use the invoice_request bytes instead of the invoice_request TLV stream as the latter may
 192                 // have contained unknown TLV records, which are not stored in `InvoiceRequestContents` or
 193                 // `RefundContents`.
 194                 let (_, _, _, invoice_tlv_stream) = self.invoice.as_tlv_stream();
 195                 let invoice_request_bytes = WithoutSignatures(self.invreq_bytes);
 196                 let unsigned_tlv_stream = (invoice_request_bytes, invoice_tlv_stream);
 197
 198                 let mut bytes = Vec::new();
 199                 unsigned_tlv_stream.write(&mut bytes).unwrap();
 200
 201                 let pubkey = self.invoice.fields().signing_pubkey;
 202                 let signature = merkle::sign_message(sign, SIGNATURE_TAG, &bytes, pubkey)?;
 203
 204                 // Append the signature TLV record to the bytes.
 205                 let signature_tlv_stream = SignatureTlvStreamRef {
 206                         signature: Some(&signature),
 207                 };
 208                 signature_tlv_stream.write(&mut bytes).unwrap();
 209
 210                 Ok(Invoice {
 211                         bytes,
 212                         contents: self.invoice,
 213                         signature,
 214                 })
 215         }
 216 }
 217
 218 /// An `Invoice` is a payment request, typically corresponding to an [`Offer`] or a [`Refund`].
 219 ///
 220 /// An invoice may be sent in response to an [`InvoiceRequest`] in the case of an offer or sent
 221 /// directly after scanning a refund. It includes all the information needed to pay a recipient.
 222 ///
 223 /// [`Offer`]: crate::offers::offer::Offer
 224 /// [`Refund`]: crate::offers::refund::Refund
 225 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 226 pub struct Invoice {
 227         bytes: Vec<u8>,
 228         contents: InvoiceContents,
 229         signature: Signature,
 230 }
 231
 232 /// The contents of an [`Invoice`] for responding to either an [`Offer`] or a [`Refund`].
 233 ///
 234 /// [`Offer`]: crate::offers::offer::Offer
 235 /// [`Refund`]: crate::offers::refund::Refund
 236 enum InvoiceContents {
 237         /// Contents for an [`Invoice`] corresponding to an [`Offer`].
 238         ///
 239         /// [`Offer`]: crate::offers::offer::Offer
 240         ForOffer {
 241                 invoice_request: InvoiceRequestContents,
 242                 fields: InvoiceFields,
 243         },
 244         /// Contents for an [`Invoice`] corresponding to a [`Refund`].
 245         ///
 246         /// [`Refund`]: crate::offers::refund::Refund
 247         ForRefund {
 248                 refund: RefundContents,
 249                 fields: InvoiceFields,
 250         },
 251 }
 252
 253 /// Invoice-specific fields for an `invoice` message.
 254 struct InvoiceFields {
 255         payment_paths: Vec<(BlindedPath, BlindedPayInfo)>,
 256         created_at: Duration,
 257         relative_expiry: Option<Duration>,
 258         payment_hash: PaymentHash,
 259         amount_msats: u64,
 260         fallbacks: Option<Vec<FallbackAddress>>,
 261         features: Bolt12InvoiceFeatures,
 262         signing_pubkey: PublicKey,
 263 }
 264
 265 impl Invoice {
 266         /// Paths to the recipient originating from publicly reachable nodes, including information
 267         /// needed for routing payments across them. Blinded paths provide recipient privacy by
 268         /// obfuscating its node id.
 269         pub fn payment_paths(&self) -> &[(BlindedPath, BlindedPayInfo)] {
 270                 &self.contents.fields().payment_paths[..]
 271         }
 272
 273         /// Duration since the Unix epoch when the invoice was created.
 274         pub fn created_at(&self) -> Duration {
 275                 self.contents.fields().created_at
 276         }
 277
 278         /// Duration since [`Invoice::created_at`] when the invoice has expired and therefore should no
 279         /// longer be paid.
 280         pub fn relative_expiry(&self) -> Duration {
 281                 self.contents.fields().relative_expiry.unwrap_or(DEFAULT_RELATIVE_EXPIRY)
 282         }
 283
 284         /// Whether the invoice has expired.
 285         #[cfg(feature = "std")]
 286         pub fn is_expired(&self) -> bool {
 287                 let absolute_expiry = self.created_at().checked_add(self.relative_expiry());
 288                 match absolute_expiry {
 289                         Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() {
 290                                 Ok(elapsed) => elapsed > seconds_from_epoch,
 291                                 Err(_) => false,
 292                         },
 293                         None => false,
 294                 }
 295         }
 296
 297         /// SHA256 hash of the payment preimage that will be given in return for paying the invoice.
 298         pub fn payment_hash(&self) -> PaymentHash {
 299                 self.contents.fields().payment_hash
 300         }
 301
 302         /// The minimum amount required for a successful payment of the invoice.
 303         pub fn amount_msats(&self) -> u64 {
 304                 self.contents.fields().amount_msats
 305         }
 306
 307         /// Fallback addresses for paying the invoice on-chain, in order of most-preferred to
 308         /// least-preferred.
 309         pub fn fallbacks(&self) -> Vec<Address> {
 310                 let network = match self.network() {
 311                         None => return Vec::new(),
 312                         Some(network) => network,
 313                 };
 314
 315                 let to_valid_address = |address: &FallbackAddress| {
 316                         let version = match WitnessVersion::try_from(address.version) {
 317                                 Ok(version) => version,
 318                                 Err(_) => return None,
 319                         };
 320
 321                         let program = &address.program;
 322                         if program.len() < 2 || program.len() > 40 {
 323                                 return None;
 324                         }
 325
 326                         let address = Address {
 327                                 payload: Payload::WitnessProgram {
 328                                         version,
 329                                         program: address.program.clone(),
 330                                 },
 331                                 network,
 332                         };
 333
 334                         if !address.is_standard() && version == WitnessVersion::V0 {
 335                                 return None;
 336                         }
 337
 338                         Some(address)
 339                 };
 340
 341                 self.contents.fields().fallbacks
 342                         .as_ref()
 343                         .map(|fallbacks| fallbacks.iter().filter_map(to_valid_address).collect())
 344                         .unwrap_or_else(Vec::new)
 345         }
 346
 347         fn network(&self) -> Option<Network> {
 348                 let chain = self.contents.chain();
 349                 if chain == ChainHash::using_genesis_block(Network::Bitcoin) {
 350                         Some(Network::Bitcoin)
 351                 } else if chain == ChainHash::using_genesis_block(Network::Testnet) {
 352                         Some(Network::Testnet)
 353                 } else if chain == ChainHash::using_genesis_block(Network::Signet) {
 354                         Some(Network::Signet)
 355                 } else if chain == ChainHash::using_genesis_block(Network::Regtest) {
 356                         Some(Network::Regtest)
 357                 } else {
 358                         None
 359                 }
 360         }
 361
 362         /// Features pertaining to paying an invoice.
 363         pub fn features(&self) -> &Bolt12InvoiceFeatures {
 364                 &self.contents.fields().features
 365         }
 366
 367         /// The public key used to sign invoices.
 368         pub fn signing_pubkey(&self) -> PublicKey {
 369                 self.contents.fields().signing_pubkey
 370         }
 371
 372         /// Signature of the invoice using [`Invoice::signing_pubkey`].
 373         pub fn signature(&self) -> Signature {
 374                 self.signature
 375         }
 376 }
 377
 378 impl InvoiceContents {
 379         /// Whether the original offer or refund has expired.
 380         #[cfg(feature = "std")]
 381         fn is_offer_or_refund_expired(&self) -> bool {
 382                 match self {
 383                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.offer.is_expired(),
 384                         InvoiceContents::ForRefund { refund, .. } => refund.is_expired(),
 385                 }
 386         }
 387
 388         fn chain(&self) -> ChainHash {
 389                 match self {
 390                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.chain(),
 391                         InvoiceContents::ForRefund { refund, .. } => refund.chain(),
 392                 }
 393         }
 394
 395         fn fields(&self) -> &InvoiceFields {
 396                 match self {
 397                         InvoiceContents::ForOffer { fields, .. } => fields,
 398                         InvoiceContents::ForRefund { fields, .. } => fields,
 399                 }
 400         }
 401
 402         fn fields_mut(&mut self) -> &mut InvoiceFields {
 403                 match self {
 404                         InvoiceContents::ForOffer { fields, .. } => fields,
 405                         InvoiceContents::ForRefund { fields, .. } => fields,
 406                 }
 407         }
 408
 409         fn as_tlv_stream(&self) -> PartialInvoiceTlvStreamRef {
 410                 let (payer, offer, invoice_request) = match self {
 411                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.as_tlv_stream(),
 412                         InvoiceContents::ForRefund { refund, .. } => refund.as_tlv_stream(),
 413                 };
 414                 let invoice = self.fields().as_tlv_stream();
 415
 416                 (payer, offer, invoice_request, invoice)
 417         }
 418 }
 419
 420 impl InvoiceFields {
 421         fn as_tlv_stream(&self) -> InvoiceTlvStreamRef {
 422                 let features = {
 423                         if self.features == Bolt12InvoiceFeatures::empty() { None }
 424                         else { Some(&self.features) }
 425                 };
 426
 427                 InvoiceTlvStreamRef {
 428                         paths: Some(Iterable(self.payment_paths.iter().map(|(path, _)| path))),
 429                         blindedpay: Some(Iterable(self.payment_paths.iter().map(|(_, payinfo)| payinfo))),
 430                         created_at: Some(self.created_at.as_secs()),
 431                         relative_expiry: self.relative_expiry.map(|duration| duration.as_secs() as u32),
 432                         payment_hash: Some(&self.payment_hash),
 433                         amount: Some(self.amount_msats),
 434                         fallbacks: self.fallbacks.as_ref(),
 435                         features,
 436                         node_id: Some(&self.signing_pubkey),
 437                 }
 438         }
 439 }
 440
 441 impl Writeable for Invoice {
 442         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 443                 WithoutLength(&self.bytes).write(writer)
 444         }
 445 }
 446
 447 impl TryFrom<Vec<u8>> for Invoice {
 448         type Error = ParseError;
 449
 450         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 451                 let parsed_invoice = ParsedMessage::<FullInvoiceTlvStream>::try_from(bytes)?;
 452                 Invoice::try_from(parsed_invoice)
 453         }
 454 }
 455
 456 tlv_stream!(InvoiceTlvStream, InvoiceTlvStreamRef, 160..240, {
 457         (160, paths: (Vec<BlindedPath>, WithoutLength, Iterable<'a, BlindedPathIter<'a>, BlindedPath>)),
 458         (162, blindedpay: (Vec<BlindedPayInfo>, WithoutLength, Iterable<'a, BlindedPayInfoIter<'a>, BlindedPayInfo>)),
 459         (164, created_at: (u64, HighZeroBytesDroppedBigSize)),
 460         (166, relative_expiry: (u32, HighZeroBytesDroppedBigSize)),
 461         (168, payment_hash: PaymentHash),
 462         (170, amount: (u64, HighZeroBytesDroppedBigSize)),
 463         (172, fallbacks: (Vec<FallbackAddress>, WithoutLength)),
 464         (174, features: (Bolt12InvoiceFeatures, WithoutLength)),
 465         (176, node_id: PublicKey),
 466 });
 467
 468 type BlindedPathIter<'a> = core::iter::Map<
 469         core::slice::Iter<'a, (BlindedPath, BlindedPayInfo)>,
 470         for<'r> fn(&'r (BlindedPath, BlindedPayInfo)) -> &'r BlindedPath,
 471 >;
 472
 473 type BlindedPayInfoIter<'a> = core::iter::Map<
 474         core::slice::Iter<'a, (BlindedPath, BlindedPayInfo)>,
 475         for<'r> fn(&'r (BlindedPath, BlindedPayInfo)) -> &'r BlindedPayInfo,
 476 >;
 477
 478 /// Information needed to route a payment across a [`BlindedPath`].
 479 #[derive(Debug, PartialEq)]
 480 pub struct BlindedPayInfo {
 481         fee_base_msat: u32,
 482         fee_proportional_millionths: u32,
 483         cltv_expiry_delta: u16,
 484         htlc_minimum_msat: u64,
 485         htlc_maximum_msat: u64,
 486         features: BlindedHopFeatures,
 487 }
 488
 489 impl_writeable!(BlindedPayInfo, {
 490         fee_base_msat,
 491         fee_proportional_millionths,
 492         cltv_expiry_delta,
 493         htlc_minimum_msat,
 494         htlc_maximum_msat,
 495         features
 496 });
 497
 498 /// Wire representation for an on-chain fallback address.
 499 #[derive(Debug, PartialEq)]
 500 pub(super) struct FallbackAddress {
 501         version: u8,
 502         program: Vec<u8>,
 503 }
 504
 505 impl_writeable!(FallbackAddress, { version, program });
 506
 507 type FullInvoiceTlvStream =
 508         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, InvoiceTlvStream, SignatureTlvStream);
 509
 510 impl SeekReadable for FullInvoiceTlvStream {
 511         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 512                 let payer = SeekReadable::read(r)?;
 513                 let offer = SeekReadable::read(r)?;
 514                 let invoice_request = SeekReadable::read(r)?;
 515                 let invoice = SeekReadable::read(r)?;
 516                 let signature = SeekReadable::read(r)?;
 517
 518                 Ok((payer, offer, invoice_request, invoice, signature))
 519         }
 520 }
 521
 522 type PartialInvoiceTlvStream =
 523         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, InvoiceTlvStream);
 524
 525 type PartialInvoiceTlvStreamRef<'a> = (
 526         PayerTlvStreamRef<'a>,
 527         OfferTlvStreamRef<'a>,
 528         InvoiceRequestTlvStreamRef<'a>,
 529         InvoiceTlvStreamRef<'a>,
 530 );
 531
 532 impl TryFrom<ParsedMessage<FullInvoiceTlvStream>> for Invoice {
 533         type Error = ParseError;
 534
 535         fn try_from(invoice: ParsedMessage<FullInvoiceTlvStream>) -> Result<Self, Self::Error> {
 536                 let ParsedMessage { bytes, tlv_stream } = invoice;
 537                 let (
 538                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
 539                         SignatureTlvStream { signature },
 540                 ) = tlv_stream;
 541                 let contents = InvoiceContents::try_from(
 542                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream)
 543                 )?;
 544
 545                 let signature = match signature {
 546                         None => return Err(ParseError::InvalidSemantics(SemanticError::MissingSignature)),
 547                         Some(signature) => signature,
 548                 };
 549                 let pubkey = contents.fields().signing_pubkey;
 550                 merkle::verify_signature(&signature, SIGNATURE_TAG, &bytes, pubkey)?;
 551
 552                 Ok(Invoice { bytes, contents, signature })
 553         }
 554 }
 555
 556 impl TryFrom<PartialInvoiceTlvStream> for InvoiceContents {
 557         type Error = SemanticError;
 558
 559         fn try_from(tlv_stream: PartialInvoiceTlvStream) -> Result<Self, Self::Error> {
 560                 let (
 561                         payer_tlv_stream,
 562                         offer_tlv_stream,
 563                         invoice_request_tlv_stream,
 564                         InvoiceTlvStream {
 565                                 paths, blindedpay, created_at, relative_expiry, payment_hash, amount, fallbacks,
 566                                 features, node_id,
 567                         },
 568                 ) = tlv_stream;
 569
 570                 let payment_paths = match (paths, blindedpay) {
 571                         (None, _) => return Err(SemanticError::MissingPaths),
 572                         (_, None) => return Err(SemanticError::InvalidPayInfo),
 573                         (Some(paths), _) if paths.is_empty() => return Err(SemanticError::MissingPaths),
 574                         (Some(paths), Some(blindedpay)) if paths.len() != blindedpay.len() => {
 575                                 return Err(SemanticError::InvalidPayInfo);
 576                         },
 577                         (Some(paths), Some(blindedpay)) => {
 578                                 paths.into_iter().zip(blindedpay.into_iter()).collect::<Vec<_>>()
 579                         },
 580                 };
 581
 582                 let created_at = match created_at {
 583                         None => return Err(SemanticError::MissingCreationTime),
 584                         Some(timestamp) => Duration::from_secs(timestamp),
 585                 };
 586
 587                 let relative_expiry = relative_expiry
 588                         .map(Into::<u64>::into)
 589                         .map(Duration::from_secs);
 590
 591                 let payment_hash = match payment_hash {
 592                         None => return Err(SemanticError::MissingPaymentHash),
 593                         Some(payment_hash) => payment_hash,
 594                 };
 595
 596                 let amount_msats = match amount {
 597                         None => return Err(SemanticError::MissingAmount),
 598                         Some(amount) => amount,
 599                 };
 600
 601                 let features = features.unwrap_or_else(Bolt12InvoiceFeatures::empty);
 602
 603                 let signing_pubkey = match node_id {
 604                         None => return Err(SemanticError::MissingSigningPubkey),
 605                         Some(node_id) => node_id,
 606                 };
 607
 608                 let fields = InvoiceFields {
 609                         payment_paths, created_at, relative_expiry, payment_hash, amount_msats, fallbacks,
 610                         features, signing_pubkey,
 611                 };
 612
 613                 match offer_tlv_stream.node_id {
 614                         Some(expected_signing_pubkey) => {
 615                                 if fields.signing_pubkey != expected_signing_pubkey {
 616                                         return Err(SemanticError::InvalidSigningPubkey);
 617                                 }
 618
 619                                 let invoice_request = InvoiceRequestContents::try_from(
 620                                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 621                                 )?;
 622                                 Ok(InvoiceContents::ForOffer { invoice_request, fields })
 623                         },
 624                         None => {
 625                                 let refund = RefundContents::try_from(
 626                                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 627                                 )?;
 628                                 Ok(InvoiceContents::ForRefund { refund, fields })
 629                         },
 630                 }
 631         }
 632 }