git.bitcoin.ninja 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 //! ```ignore
  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 //!     .respond_with(payment_paths, payment_hash)?
  49 //!     .relative_expiry(3600)
  50 //!     .allow_mpp()
  51 //!     .fallback_v0_p2wpkh(&wpubkey_hash)
  52 //!     .build()?
  53 //!     .sign::<_, Infallible>(|digest| Ok(secp_ctx.sign_schnorr_no_aux_rand(digest, &keys)))
  54 //!     .expect("failed verifying signature")
  55 //!     .write(&mut buffer)
  56 //!     .unwrap();
  57 //! # Ok(())
  58 //! # }
  59 //!
  60 //! # fn parse_refund(bytes: Vec<u8>) -> Result<(), lightning::offers::parse::ParseError> {
  61 //! # let payment_paths = create_payment_paths();
  62 //! # let payment_hash = create_payment_hash();
  63 //! # let secp_ctx = Secp256k1::new();
  64 //! # let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32])?);
  65 //! # let pubkey = PublicKey::from(keys);
  66 //! # let wpubkey_hash = bitcoin::util::key::PublicKey::new(pubkey).wpubkey_hash().unwrap();
  67 //! # let mut buffer = Vec::new();
  68 //!
  69 //! // Invoice for the "offer for money" flow.
  70 //! "lnr1qcp4256ypq"
  71 //!     .parse::<Refund>()?
  72 //!     .respond_with(payment_paths, payment_hash, pubkey)?
  73 //!     .relative_expiry(3600)
  74 //!     .allow_mpp()
  75 //!     .fallback_v0_p2wpkh(&wpubkey_hash)
  76 //!     .build()?
  77 //!     .sign::<_, Infallible>(|digest| Ok(secp_ctx.sign_schnorr_no_aux_rand(digest, &keys)))
  78 //!     .expect("failed verifying signature")
  79 //!     .write(&mut buffer)
  80 //!     .unwrap();
  81 //! # Ok(())
  82 //! # }
  83 //!
  84 //! ```
  85
  86 use bitcoin::blockdata::constants::ChainHash;
  87 use bitcoin::hash_types::{WPubkeyHash, WScriptHash};
  88 use bitcoin::hashes::Hash;
  89 use bitcoin::network::constants::Network;
  90 use bitcoin::secp256k1::{Message, PublicKey};
  91 use bitcoin::secp256k1::schnorr::Signature;
  92 use bitcoin::util::address::{Address, Payload, WitnessVersion};
  93 use bitcoin::util::schnorr::TweakedPublicKey;
  94 use core::convert::TryFrom;
  95 use core::time::Duration;
  96 use crate::io;
  97 use crate::ln::PaymentHash;
  98 use crate::ln::features::{BlindedHopFeatures, Bolt12InvoiceFeatures};
  99 use crate::ln::msgs::DecodeError;
 100 use crate::offers::invoice_request::{InvoiceRequest, InvoiceRequestContents, InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef};
 101 use crate::offers::merkle::{SignError, SignatureTlvStream, SignatureTlvStreamRef, WithoutSignatures, self};
 102 use crate::offers::offer::{Amount, OfferTlvStream, OfferTlvStreamRef};
 103 use crate::offers::parse::{ParseError, ParsedMessage, SemanticError};
 104 use crate::offers::payer::{PayerTlvStream, PayerTlvStreamRef};
 105 use crate::offers::refund::{Refund, RefundContents};
 106 use crate::onion_message::BlindedPath;
 107 use crate::util::ser::{HighZeroBytesDroppedBigSize, Iterable, SeekReadable, WithoutLength, Writeable, Writer};
 108
 109 use crate::prelude::*;
 110
 111 #[cfg(feature = "std")]
 112 use std::time::SystemTime;
 113
 114 const DEFAULT_RELATIVE_EXPIRY: Duration = Duration::from_secs(7200);
 115
 116 const SIGNATURE_TAG: &'static str = concat!("lightning", "invoice", "signature");
 117
 118 /// Builds an [`Invoice`] from either:
 119 /// - an [`InvoiceRequest`] for the "offer to be paid" flow or
 120 /// - a [`Refund`] for the "offer for money" flow.
 121 ///
 122 /// See [module-level documentation] for usage.
 123 ///
 124 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 125 /// [`Refund`]: crate::offers::refund::Refund
 126 /// [module-level documentation]: self
 127 pub struct InvoiceBuilder<'a> {
 128         invreq_bytes: &'a Vec<u8>,
 129         invoice: InvoiceContents,
 130 }
 131
 132 impl<'a> InvoiceBuilder<'a> {
 133         pub(super) fn for_offer(
 134                 invoice_request: &'a InvoiceRequest, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>,
 135                 created_at: Duration, payment_hash: PaymentHash
 136         ) -> Result<Self, SemanticError> {
 137                 let amount_msats = match invoice_request.amount_msats() {
 138                         Some(amount_msats) => amount_msats,
 139                         None => match invoice_request.contents.offer.amount() {
 140                                 Some(Amount::Bitcoin { amount_msats }) => {
 141                                         amount_msats * invoice_request.quantity().unwrap_or(1)
 142                                 },
 143                                 Some(Amount::Currency { .. }) => return Err(SemanticError::UnsupportedCurrency),
 144                                 None => return Err(SemanticError::MissingAmount),
 145                         },
 146                 };
 147
 148                 let contents = InvoiceContents::ForOffer {
 149                         invoice_request: invoice_request.contents.clone(),
 150                         fields: InvoiceFields {
 151                                 payment_paths, created_at, relative_expiry: None, payment_hash, amount_msats,
 152                                 fallbacks: None, features: Bolt12InvoiceFeatures::empty(),
 153                                 signing_pubkey: invoice_request.contents.offer.signing_pubkey(),
 154                         },
 155                 };
 156
 157                 Self::new(&invoice_request.bytes, contents)
 158         }
 159
 160         pub(super) fn for_refund(
 161                 refund: &'a Refund, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>, created_at: Duration,
 162                 payment_hash: PaymentHash, signing_pubkey: PublicKey
 163         ) -> Result<Self, SemanticError> {
 164                 let contents = InvoiceContents::ForRefund {
 165                         refund: refund.contents.clone(),
 166                         fields: InvoiceFields {
 167                                 payment_paths, created_at, relative_expiry: None, payment_hash,
 168                                 amount_msats: refund.amount_msats(), fallbacks: None,
 169                                 features: Bolt12InvoiceFeatures::empty(), signing_pubkey,
 170                         },
 171                 };
 172
 173                 Self::new(&refund.bytes, contents)
 174         }
 175
 176         fn new(invreq_bytes: &'a Vec<u8>, contents: InvoiceContents) -> Result<Self, SemanticError> {
 177                 if contents.fields().payment_paths.is_empty() {
 178                         return Err(SemanticError::MissingPaths);
 179                 }
 180
 181                 Ok(Self { invreq_bytes, invoice: contents })
 182         }
 183
 184         /// Sets the [`Invoice::relative_expiry`] as seconds since [`Invoice::created_at`]. Any expiry
 185         /// that has already passed is valid and can be checked for using [`Invoice::is_expired`].
 186         ///
 187         /// Successive calls to this method will override the previous setting.
 188         pub fn relative_expiry(mut self, relative_expiry_secs: u32) -> Self {
 189                 let relative_expiry = Duration::from_secs(relative_expiry_secs as u64);
 190                 self.invoice.fields_mut().relative_expiry = Some(relative_expiry);
 191                 self
 192         }
 193
 194         /// Adds a P2WSH address to [`Invoice::fallbacks`].
 195         ///
 196         /// Successive calls to this method will add another address. Caller is responsible for not
 197         /// adding duplicate addresses and only calling if capable of receiving to P2WSH addresses.
 198         pub fn fallback_v0_p2wsh(mut self, script_hash: &WScriptHash) -> Self {
 199                 let address = FallbackAddress {
 200                         version: WitnessVersion::V0.to_num(),
 201                         program: Vec::from(&script_hash.into_inner()[..]),
 202                 };
 203                 self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
 204                 self
 205         }
 206
 207         /// Adds a P2WPKH address to [`Invoice::fallbacks`].
 208         ///
 209         /// Successive calls to this method will add another address. Caller is responsible for not
 210         /// adding duplicate addresses and only calling if capable of receiving to P2WPKH addresses.
 211         pub fn fallback_v0_p2wpkh(mut self, pubkey_hash: &WPubkeyHash) -> Self {
 212                 let address = FallbackAddress {
 213                         version: WitnessVersion::V0.to_num(),
 214                         program: Vec::from(&pubkey_hash.into_inner()[..]),
 215                 };
 216                 self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
 217                 self
 218         }
 219
 220         /// Adds a P2TR address to [`Invoice::fallbacks`].
 221         ///
 222         /// Successive calls to this method will add another address. Caller is responsible for not
 223         /// adding duplicate addresses and only calling if capable of receiving to P2TR addresses.
 224         pub fn fallback_v1_p2tr_tweaked(mut self, output_key: &TweakedPublicKey) -> Self {
 225                 let address = FallbackAddress {
 226                         version: WitnessVersion::V1.to_num(),
 227                         program: Vec::from(&output_key.serialize()[..]),
 228                 };
 229                 self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
 230                 self
 231         }
 232
 233         /// Sets [`Invoice::features`] to indicate MPP may be used. Otherwise, MPP is disallowed.
 234         pub fn allow_mpp(mut self) -> Self {
 235                 self.invoice.fields_mut().features.set_basic_mpp_optional();
 236                 self
 237         }
 238
 239         /// Builds an unsigned [`Invoice`] after checking for valid semantics. It can be signed by
 240         /// [`UnsignedInvoice::sign`].
 241         pub fn build(self) -> Result<UnsignedInvoice<'a>, SemanticError> {
 242                 #[cfg(feature = "std")] {
 243                         if self.invoice.is_offer_or_refund_expired() {
 244                                 return Err(SemanticError::AlreadyExpired);
 245                         }
 246                 }
 247
 248                 let InvoiceBuilder { invreq_bytes, invoice } = self;
 249                 Ok(UnsignedInvoice { invreq_bytes, invoice })
 250         }
 251 }
 252
 253 /// A semantically valid [`Invoice`] that hasn't been signed.
 254 pub struct UnsignedInvoice<'a> {
 255         invreq_bytes: &'a Vec<u8>,
 256         invoice: InvoiceContents,
 257 }
 258
 259 impl<'a> UnsignedInvoice<'a> {
 260         /// Signs the invoice using the given function.
 261         pub fn sign<F, E>(self, sign: F) -> Result<Invoice, SignError<E>>
 262         where
 263                 F: FnOnce(&Message) -> Result<Signature, E>
 264         {
 265                 // Use the invoice_request bytes instead of the invoice_request TLV stream as the latter may
 266                 // have contained unknown TLV records, which are not stored in `InvoiceRequestContents` or
 267                 // `RefundContents`.
 268                 let (_, _, _, invoice_tlv_stream) = self.invoice.as_tlv_stream();
 269                 let invoice_request_bytes = WithoutSignatures(self.invreq_bytes);
 270                 let unsigned_tlv_stream = (invoice_request_bytes, invoice_tlv_stream);
 271
 272                 let mut bytes = Vec::new();
 273                 unsigned_tlv_stream.write(&mut bytes).unwrap();
 274
 275                 let pubkey = self.invoice.fields().signing_pubkey;
 276                 let signature = merkle::sign_message(sign, SIGNATURE_TAG, &bytes, pubkey)?;
 277
 278                 // Append the signature TLV record to the bytes.
 279                 let signature_tlv_stream = SignatureTlvStreamRef {
 280                         signature: Some(&signature),
 281                 };
 282                 signature_tlv_stream.write(&mut bytes).unwrap();
 283
 284                 Ok(Invoice {
 285                         bytes,
 286                         contents: self.invoice,
 287                         signature,
 288                 })
 289         }
 290 }
 291
 292 /// An `Invoice` is a payment request, typically corresponding to an [`Offer`] or a [`Refund`].
 293 ///
 294 /// An invoice may be sent in response to an [`InvoiceRequest`] in the case of an offer or sent
 295 /// directly after scanning a refund. It includes all the information needed to pay a recipient.
 296 ///
 297 /// [`Offer`]: crate::offers::offer::Offer
 298 /// [`Refund`]: crate::offers::refund::Refund
 299 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 300 pub struct Invoice {
 301         bytes: Vec<u8>,
 302         contents: InvoiceContents,
 303         signature: Signature,
 304 }
 305
 306 /// The contents of an [`Invoice`] for responding to either an [`Offer`] or a [`Refund`].
 307 ///
 308 /// [`Offer`]: crate::offers::offer::Offer
 309 /// [`Refund`]: crate::offers::refund::Refund
 310 enum InvoiceContents {
 311         /// Contents for an [`Invoice`] corresponding to an [`Offer`].
 312         ///
 313         /// [`Offer`]: crate::offers::offer::Offer
 314         ForOffer {
 315                 invoice_request: InvoiceRequestContents,
 316                 fields: InvoiceFields,
 317         },
 318         /// Contents for an [`Invoice`] corresponding to a [`Refund`].
 319         ///
 320         /// [`Refund`]: crate::offers::refund::Refund
 321         ForRefund {
 322                 refund: RefundContents,
 323                 fields: InvoiceFields,
 324         },
 325 }
 326
 327 /// Invoice-specific fields for an `invoice` message.
 328 struct InvoiceFields {
 329         payment_paths: Vec<(BlindedPath, BlindedPayInfo)>,
 330         created_at: Duration,
 331         relative_expiry: Option<Duration>,
 332         payment_hash: PaymentHash,
 333         amount_msats: u64,
 334         fallbacks: Option<Vec<FallbackAddress>>,
 335         features: Bolt12InvoiceFeatures,
 336         signing_pubkey: PublicKey,
 337 }
 338
 339 impl Invoice {
 340         /// Paths to the recipient originating from publicly reachable nodes, including information
 341         /// needed for routing payments across them. Blinded paths provide recipient privacy by
 342         /// obfuscating its node id.
 343         pub fn payment_paths(&self) -> &[(BlindedPath, BlindedPayInfo)] {
 344                 &self.contents.fields().payment_paths[..]
 345         }
 346
 347         /// Duration since the Unix epoch when the invoice was created.
 348         pub fn created_at(&self) -> Duration {
 349                 self.contents.fields().created_at
 350         }
 351
 352         /// Duration since [`Invoice::created_at`] when the invoice has expired and therefore should no
 353         /// longer be paid.
 354         pub fn relative_expiry(&self) -> Duration {
 355                 self.contents.fields().relative_expiry.unwrap_or(DEFAULT_RELATIVE_EXPIRY)
 356         }
 357
 358         /// Whether the invoice has expired.
 359         #[cfg(feature = "std")]
 360         pub fn is_expired(&self) -> bool {
 361                 let absolute_expiry = self.created_at().checked_add(self.relative_expiry());
 362                 match absolute_expiry {
 363                         Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() {
 364                                 Ok(elapsed) => elapsed > seconds_from_epoch,
 365                                 Err(_) => false,
 366                         },
 367                         None => false,
 368                 }
 369         }
 370
 371         /// SHA256 hash of the payment preimage that will be given in return for paying the invoice.
 372         pub fn payment_hash(&self) -> PaymentHash {
 373                 self.contents.fields().payment_hash
 374         }
 375
 376         /// The minimum amount required for a successful payment of the invoice.
 377         pub fn amount_msats(&self) -> u64 {
 378                 self.contents.fields().amount_msats
 379         }
 380
 381         /// Fallback addresses for paying the invoice on-chain, in order of most-preferred to
 382         /// least-preferred.
 383         pub fn fallbacks(&self) -> Vec<Address> {
 384                 let network = match self.network() {
 385                         None => return Vec::new(),
 386                         Some(network) => network,
 387                 };
 388
 389                 let to_valid_address = |address: &FallbackAddress| {
 390                         let version = match WitnessVersion::try_from(address.version) {
 391                                 Ok(version) => version,
 392                                 Err(_) => return None,
 393                         };
 394
 395                         let program = &address.program;
 396                         if program.len() < 2 || program.len() > 40 {
 397                                 return None;
 398                         }
 399
 400                         let address = Address {
 401                                 payload: Payload::WitnessProgram {
 402                                         version,
 403                                         program: address.program.clone(),
 404                                 },
 405                                 network,
 406                         };
 407
 408                         if !address.is_standard() && version == WitnessVersion::V0 {
 409                                 return None;
 410                         }
 411
 412                         Some(address)
 413                 };
 414
 415                 self.contents.fields().fallbacks
 416                         .as_ref()
 417                         .map(|fallbacks| fallbacks.iter().filter_map(to_valid_address).collect())
 418                         .unwrap_or_else(Vec::new)
 419         }
 420
 421         fn network(&self) -> Option<Network> {
 422                 let chain = self.contents.chain();
 423                 if chain == ChainHash::using_genesis_block(Network::Bitcoin) {
 424                         Some(Network::Bitcoin)
 425                 } else if chain == ChainHash::using_genesis_block(Network::Testnet) {
 426                         Some(Network::Testnet)
 427                 } else if chain == ChainHash::using_genesis_block(Network::Signet) {
 428                         Some(Network::Signet)
 429                 } else if chain == ChainHash::using_genesis_block(Network::Regtest) {
 430                         Some(Network::Regtest)
 431                 } else {
 432                         None
 433                 }
 434         }
 435
 436         /// Features pertaining to paying an invoice.
 437         pub fn features(&self) -> &Bolt12InvoiceFeatures {
 438                 &self.contents.fields().features
 439         }
 440
 441         /// The public key used to sign invoices.
 442         pub fn signing_pubkey(&self) -> PublicKey {
 443                 self.contents.fields().signing_pubkey
 444         }
 445
 446         /// Signature of the invoice using [`Invoice::signing_pubkey`].
 447         pub fn signature(&self) -> Signature {
 448                 self.signature
 449         }
 450 }
 451
 452 impl InvoiceContents {
 453         /// Whether the original offer or refund has expired.
 454         #[cfg(feature = "std")]
 455         fn is_offer_or_refund_expired(&self) -> bool {
 456                 match self {
 457                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.offer.is_expired(),
 458                         InvoiceContents::ForRefund { refund, .. } => refund.is_expired(),
 459                 }
 460         }
 461
 462         fn chain(&self) -> ChainHash {
 463                 match self {
 464                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.chain(),
 465                         InvoiceContents::ForRefund { refund, .. } => refund.chain(),
 466                 }
 467         }
 468
 469         fn fields(&self) -> &InvoiceFields {
 470                 match self {
 471                         InvoiceContents::ForOffer { fields, .. } => fields,
 472                         InvoiceContents::ForRefund { fields, .. } => fields,
 473                 }
 474         }
 475
 476         fn fields_mut(&mut self) -> &mut InvoiceFields {
 477                 match self {
 478                         InvoiceContents::ForOffer { fields, .. } => fields,
 479                         InvoiceContents::ForRefund { fields, .. } => fields,
 480                 }
 481         }
 482
 483         fn as_tlv_stream(&self) -> PartialInvoiceTlvStreamRef {
 484                 let (payer, offer, invoice_request) = match self {
 485                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.as_tlv_stream(),
 486                         InvoiceContents::ForRefund { refund, .. } => refund.as_tlv_stream(),
 487                 };
 488                 let invoice = self.fields().as_tlv_stream();
 489
 490                 (payer, offer, invoice_request, invoice)
 491         }
 492 }
 493
 494 impl InvoiceFields {
 495         fn as_tlv_stream(&self) -> InvoiceTlvStreamRef {
 496                 let features = {
 497                         if self.features == Bolt12InvoiceFeatures::empty() { None }
 498                         else { Some(&self.features) }
 499                 };
 500
 501                 InvoiceTlvStreamRef {
 502                         paths: Some(Iterable(self.payment_paths.iter().map(|(path, _)| path))),
 503                         blindedpay: Some(Iterable(self.payment_paths.iter().map(|(_, payinfo)| payinfo))),
 504                         created_at: Some(self.created_at.as_secs()),
 505                         relative_expiry: self.relative_expiry.map(|duration| duration.as_secs() as u32),
 506                         payment_hash: Some(&self.payment_hash),
 507                         amount: Some(self.amount_msats),
 508                         fallbacks: self.fallbacks.as_ref(),
 509                         features,
 510                         node_id: Some(&self.signing_pubkey),
 511                 }
 512         }
 513 }
 514
 515 impl Writeable for Invoice {
 516         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 517                 WithoutLength(&self.bytes).write(writer)
 518         }
 519 }
 520
 521 impl TryFrom<Vec<u8>> for Invoice {
 522         type Error = ParseError;
 523
 524         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 525                 let parsed_invoice = ParsedMessage::<FullInvoiceTlvStream>::try_from(bytes)?;
 526                 Invoice::try_from(parsed_invoice)
 527         }
 528 }
 529
 530 tlv_stream!(InvoiceTlvStream, InvoiceTlvStreamRef, 160..240, {
 531         (160, paths: (Vec<BlindedPath>, WithoutLength, Iterable<'a, BlindedPathIter<'a>, BlindedPath>)),
 532         (162, blindedpay: (Vec<BlindedPayInfo>, WithoutLength, Iterable<'a, BlindedPayInfoIter<'a>, BlindedPayInfo>)),
 533         (164, created_at: (u64, HighZeroBytesDroppedBigSize)),
 534         (166, relative_expiry: (u32, HighZeroBytesDroppedBigSize)),
 535         (168, payment_hash: PaymentHash),
 536         (170, amount: (u64, HighZeroBytesDroppedBigSize)),
 537         (172, fallbacks: (Vec<FallbackAddress>, WithoutLength)),
 538         (174, features: (Bolt12InvoiceFeatures, WithoutLength)),
 539         (176, node_id: PublicKey),
 540 });
 541
 542 type BlindedPathIter<'a> = core::iter::Map<
 543         core::slice::Iter<'a, (BlindedPath, BlindedPayInfo)>,
 544         for<'r> fn(&'r (BlindedPath, BlindedPayInfo)) -> &'r BlindedPath,
 545 >;
 546
 547 type BlindedPayInfoIter<'a> = core::iter::Map<
 548         core::slice::Iter<'a, (BlindedPath, BlindedPayInfo)>,
 549         for<'r> fn(&'r (BlindedPath, BlindedPayInfo)) -> &'r BlindedPayInfo,
 550 >;
 551
 552 /// Information needed to route a payment across a [`BlindedPath`].
 553 #[derive(Debug, PartialEq)]
 554 pub struct BlindedPayInfo {
 555         fee_base_msat: u32,
 556         fee_proportional_millionths: u32,
 557         cltv_expiry_delta: u16,
 558         htlc_minimum_msat: u64,
 559         htlc_maximum_msat: u64,
 560         features: BlindedHopFeatures,
 561 }
 562
 563 impl_writeable!(BlindedPayInfo, {
 564         fee_base_msat,
 565         fee_proportional_millionths,
 566         cltv_expiry_delta,
 567         htlc_minimum_msat,
 568         htlc_maximum_msat,
 569         features
 570 });
 571
 572 /// Wire representation for an on-chain fallback address.
 573 #[derive(Debug, PartialEq)]
 574 pub(super) struct FallbackAddress {
 575         version: u8,
 576         program: Vec<u8>,
 577 }
 578
 579 impl_writeable!(FallbackAddress, { version, program });
 580
 581 type FullInvoiceTlvStream =
 582         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, InvoiceTlvStream, SignatureTlvStream);
 583
 584 impl SeekReadable for FullInvoiceTlvStream {
 585         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 586                 let payer = SeekReadable::read(r)?;
 587                 let offer = SeekReadable::read(r)?;
 588                 let invoice_request = SeekReadable::read(r)?;
 589                 let invoice = SeekReadable::read(r)?;
 590                 let signature = SeekReadable::read(r)?;
 591
 592                 Ok((payer, offer, invoice_request, invoice, signature))
 593         }
 594 }
 595
 596 type PartialInvoiceTlvStream =
 597         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, InvoiceTlvStream);
 598
 599 type PartialInvoiceTlvStreamRef<'a> = (
 600         PayerTlvStreamRef<'a>,
 601         OfferTlvStreamRef<'a>,
 602         InvoiceRequestTlvStreamRef<'a>,
 603         InvoiceTlvStreamRef<'a>,
 604 );
 605
 606 impl TryFrom<ParsedMessage<FullInvoiceTlvStream>> for Invoice {
 607         type Error = ParseError;
 608
 609         fn try_from(invoice: ParsedMessage<FullInvoiceTlvStream>) -> Result<Self, Self::Error> {
 610                 let ParsedMessage { bytes, tlv_stream } = invoice;
 611                 let (
 612                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
 613                         SignatureTlvStream { signature },
 614                 ) = tlv_stream;
 615                 let contents = InvoiceContents::try_from(
 616                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream)
 617                 )?;
 618
 619                 let signature = match signature {
 620                         None => return Err(ParseError::InvalidSemantics(SemanticError::MissingSignature)),
 621                         Some(signature) => signature,
 622                 };
 623                 let pubkey = contents.fields().signing_pubkey;
 624                 merkle::verify_signature(&signature, SIGNATURE_TAG, &bytes, pubkey)?;
 625
 626                 Ok(Invoice { bytes, contents, signature })
 627         }
 628 }
 629
 630 impl TryFrom<PartialInvoiceTlvStream> for InvoiceContents {
 631         type Error = SemanticError;
 632
 633         fn try_from(tlv_stream: PartialInvoiceTlvStream) -> Result<Self, Self::Error> {
 634                 let (
 635                         payer_tlv_stream,
 636                         offer_tlv_stream,
 637                         invoice_request_tlv_stream,
 638                         InvoiceTlvStream {
 639                                 paths, blindedpay, created_at, relative_expiry, payment_hash, amount, fallbacks,
 640                                 features, node_id,
 641                         },
 642                 ) = tlv_stream;
 643
 644                 let payment_paths = match (paths, blindedpay) {
 645                         (None, _) => return Err(SemanticError::MissingPaths),
 646                         (_, None) => return Err(SemanticError::InvalidPayInfo),
 647                         (Some(paths), _) if paths.is_empty() => return Err(SemanticError::MissingPaths),
 648                         (Some(paths), Some(blindedpay)) if paths.len() != blindedpay.len() => {
 649                                 return Err(SemanticError::InvalidPayInfo);
 650                         },
 651                         (Some(paths), Some(blindedpay)) => {
 652                                 paths.into_iter().zip(blindedpay.into_iter()).collect::<Vec<_>>()
 653                         },
 654                 };
 655
 656                 let created_at = match created_at {
 657                         None => return Err(SemanticError::MissingCreationTime),
 658                         Some(timestamp) => Duration::from_secs(timestamp),
 659                 };
 660
 661                 let relative_expiry = relative_expiry
 662                         .map(Into::<u64>::into)
 663                         .map(Duration::from_secs);
 664
 665                 let payment_hash = match payment_hash {
 666                         None => return Err(SemanticError::MissingPaymentHash),
 667                         Some(payment_hash) => payment_hash,
 668                 };
 669
 670                 let amount_msats = match amount {
 671                         None => return Err(SemanticError::MissingAmount),
 672                         Some(amount) => amount,
 673                 };
 674
 675                 let features = features.unwrap_or_else(Bolt12InvoiceFeatures::empty);
 676
 677                 let signing_pubkey = match node_id {
 678                         None => return Err(SemanticError::MissingSigningPubkey),
 679                         Some(node_id) => node_id,
 680                 };
 681
 682                 let fields = InvoiceFields {
 683                         payment_paths, created_at, relative_expiry, payment_hash, amount_msats, fallbacks,
 684                         features, signing_pubkey,
 685                 };
 686
 687                 match offer_tlv_stream.node_id {
 688                         Some(expected_signing_pubkey) => {
 689                                 if fields.signing_pubkey != expected_signing_pubkey {
 690                                         return Err(SemanticError::InvalidSigningPubkey);
 691                                 }
 692
 693                                 let invoice_request = InvoiceRequestContents::try_from(
 694                                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 695                                 )?;
 696                                 Ok(InvoiceContents::ForOffer { invoice_request, fields })
 697                         },
 698                         None => {
 699                                 let refund = RefundContents::try_from(
 700                                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 701                                 )?;
 702                                 Ok(InvoiceContents::ForRefund { refund, fields })
 703                         },
 704                 }
 705         }
 706 }