_ 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 //! A [`Bolt12Invoice`] can be built from a parsed [`InvoiceRequest`] for the "offer to be paid"
  13 //! flow or from a [`Refund`] as an "offer for money" flow. The expected recipient of the payment
  14 //! then sends 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::blinded_path::BlindedPath;
  33 //! #
  34 //! # fn create_payment_paths() -> Vec<(BlindedPayInfo, BlindedPath)> { unimplemented!() }
  35 //! # fn create_payment_hash() -> PaymentHash { unimplemented!() }
  36 //! #
  37 //! # fn parse_invoice_request(bytes: Vec<u8>) -> Result<(), lightning::offers::parse::Bolt12ParseError> {
  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>(
  59 //!         |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
  60 //!     )
  61 //!     .expect("failed verifying signature")
  62 //!     .write(&mut buffer)
  63 //!     .unwrap();
  64 //! # Ok(())
  65 //! # }
  66 //!
  67 //! # fn parse_refund(bytes: Vec<u8>) -> Result<(), lightning::offers::parse::Bolt12ParseError> {
  68 //! # let payment_paths = create_payment_paths();
  69 //! # let payment_hash = create_payment_hash();
  70 //! # let secp_ctx = Secp256k1::new();
  71 //! # let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32])?);
  72 //! # let pubkey = PublicKey::from(keys);
  73 //! # let wpubkey_hash = bitcoin::util::key::PublicKey::new(pubkey).wpubkey_hash().unwrap();
  74 //! # let mut buffer = Vec::new();
  75 //!
  76 //! // Invoice for the "offer for money" flow.
  77 //! "lnr1qcp4256ypq"
  78 //!     .parse::<Refund>()?
  79 #![cfg_attr(feature = "std", doc = "
  80     .respond_with(payment_paths, payment_hash, pubkey)?
  81 ")]
  82 #![cfg_attr(not(feature = "std"), doc = "
  83     .respond_with_no_std(payment_paths, payment_hash, pubkey, core::time::Duration::from_secs(0))?
  84 ")]
  85 //!     .relative_expiry(3600)
  86 //!     .allow_mpp()
  87 //!     .fallback_v0_p2wpkh(&wpubkey_hash)
  88 //!     .build()?
  89 //!     .sign::<_, Infallible>(
  90 //!         |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
  91 //!     )
  92 //!     .expect("failed verifying signature")
  93 //!     .write(&mut buffer)
  94 //!     .unwrap();
  95 //! # Ok(())
  96 //! # }
  97 //!
  98 //! ```
  99
 100 use bitcoin::blockdata::constants::ChainHash;
 101 use bitcoin::hash_types::{WPubkeyHash, WScriptHash};
 102 use bitcoin::hashes::Hash;
 103 use bitcoin::network::constants::Network;
 104 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, self};
 105 use bitcoin::secp256k1::schnorr::Signature;
 106 use bitcoin::util::address::{Address, Payload, WitnessVersion};
 107 use bitcoin::util::schnorr::TweakedPublicKey;
 108 use core::convert::{AsRef, Infallible, TryFrom};
 109 use core::time::Duration;
 110 use crate::io;
 111 use crate::blinded_path::BlindedPath;
 112 use crate::ln::PaymentHash;
 113 use crate::ln::features::{BlindedHopFeatures, Bolt12InvoiceFeatures};
 114 use crate::ln::inbound_payment::ExpandedKey;
 115 use crate::ln::msgs::DecodeError;
 116 use crate::offers::invoice_request::{INVOICE_REQUEST_PAYER_ID_TYPE, INVOICE_REQUEST_TYPES, IV_BYTES as INVOICE_REQUEST_IV_BYTES, InvoiceRequest, InvoiceRequestContents, InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef};
 117 use crate::offers::merkle::{SignError, SignatureTlvStream, SignatureTlvStreamRef, TaggedHash, TlvStream, WithoutSignatures, self};
 118 use crate::offers::offer::{Amount, OFFER_TYPES, OfferTlvStream, OfferTlvStreamRef};
 119 use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError, ParsedMessage};
 120 use crate::offers::payer::{PAYER_METADATA_TYPE, PayerTlvStream, PayerTlvStreamRef};
 121 use crate::offers::refund::{IV_BYTES as REFUND_IV_BYTES, Refund, RefundContents};
 122 use crate::offers::signer;
 123 use crate::util::ser::{HighZeroBytesDroppedBigSize, Iterable, SeekReadable, WithoutLength, Writeable, Writer};
 124 use crate::util::string::PrintableString;
 125
 126 use crate::prelude::*;
 127
 128 #[cfg(feature = "std")]
 129 use std::time::SystemTime;
 130
 131 const DEFAULT_RELATIVE_EXPIRY: Duration = Duration::from_secs(7200);
 132
 133 /// Tag for the hash function used when signing a [`Bolt12Invoice`]'s merkle root.
 134 pub const SIGNATURE_TAG: &'static str = concat!("lightning", "invoice", "signature");
 135
 136 /// Builds a [`Bolt12Invoice`] from either:
 137 /// - an [`InvoiceRequest`] for the "offer to be paid" flow or
 138 /// - a [`Refund`] for the "offer for money" flow.
 139 ///
 140 /// See [module-level documentation] for usage.
 141 ///
 142 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 143 ///
 144 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 145 /// [`Refund`]: crate::offers::refund::Refund
 146 /// [module-level documentation]: self
 147 pub struct InvoiceBuilder<'a, S: SigningPubkeyStrategy> {
 148         invreq_bytes: &'a Vec<u8>,
 149         invoice: InvoiceContents,
 150         signing_pubkey_strategy: S,
 151 }
 152
 153 /// Indicates how [`Bolt12Invoice::signing_pubkey`] was set.
 154 ///
 155 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 156 pub trait SigningPubkeyStrategy {}
 157
 158 /// [`Bolt12Invoice::signing_pubkey`] was explicitly set.
 159 ///
 160 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 161 pub struct ExplicitSigningPubkey {}
 162
 163 /// [`Bolt12Invoice::signing_pubkey`] was derived.
 164 ///
 165 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 166 pub struct DerivedSigningPubkey(KeyPair);
 167
 168 impl SigningPubkeyStrategy for ExplicitSigningPubkey {}
 169 impl SigningPubkeyStrategy for DerivedSigningPubkey {}
 170
 171 impl<'a> InvoiceBuilder<'a, ExplicitSigningPubkey> {
 172         pub(super) fn for_offer(
 173                 invoice_request: &'a InvoiceRequest, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>,
 174                 created_at: Duration, payment_hash: PaymentHash
 175         ) -> Result<Self, Bolt12SemanticError> {
 176                 let amount_msats = Self::check_amount_msats(invoice_request)?;
 177                 let signing_pubkey = invoice_request.contents.inner.offer.signing_pubkey();
 178                 let contents = InvoiceContents::ForOffer {
 179                         invoice_request: invoice_request.contents.clone(),
 180                         fields: Self::fields(
 181                                 payment_paths, created_at, payment_hash, amount_msats, signing_pubkey
 182                         ),
 183                 };
 184
 185                 Self::new(&invoice_request.bytes, contents, ExplicitSigningPubkey {})
 186         }
 187
 188         pub(super) fn for_refund(
 189                 refund: &'a Refund, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, created_at: Duration,
 190                 payment_hash: PaymentHash, signing_pubkey: PublicKey
 191         ) -> Result<Self, Bolt12SemanticError> {
 192                 let amount_msats = refund.amount_msats();
 193                 let contents = InvoiceContents::ForRefund {
 194                         refund: refund.contents.clone(),
 195                         fields: Self::fields(
 196                                 payment_paths, created_at, payment_hash, amount_msats, signing_pubkey
 197                         ),
 198                 };
 199
 200                 Self::new(&refund.bytes, contents, ExplicitSigningPubkey {})
 201         }
 202 }
 203
 204 impl<'a> InvoiceBuilder<'a, DerivedSigningPubkey> {
 205         pub(super) fn for_offer_using_keys(
 206                 invoice_request: &'a InvoiceRequest, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>,
 207                 created_at: Duration, payment_hash: PaymentHash, keys: KeyPair
 208         ) -> Result<Self, Bolt12SemanticError> {
 209                 let amount_msats = Self::check_amount_msats(invoice_request)?;
 210                 let signing_pubkey = invoice_request.contents.inner.offer.signing_pubkey();
 211                 let contents = InvoiceContents::ForOffer {
 212                         invoice_request: invoice_request.contents.clone(),
 213                         fields: Self::fields(
 214                                 payment_paths, created_at, payment_hash, amount_msats, signing_pubkey
 215                         ),
 216                 };
 217
 218                 Self::new(&invoice_request.bytes, contents, DerivedSigningPubkey(keys))
 219         }
 220
 221         pub(super) fn for_refund_using_keys(
 222                 refund: &'a Refund, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, created_at: Duration,
 223                 payment_hash: PaymentHash, keys: KeyPair,
 224         ) -> Result<Self, Bolt12SemanticError> {
 225                 let amount_msats = refund.amount_msats();
 226                 let signing_pubkey = keys.public_key();
 227                 let contents = InvoiceContents::ForRefund {
 228                         refund: refund.contents.clone(),
 229                         fields: Self::fields(
 230                                 payment_paths, created_at, payment_hash, amount_msats, signing_pubkey
 231                         ),
 232                 };
 233
 234                 Self::new(&refund.bytes, contents, DerivedSigningPubkey(keys))
 235         }
 236 }
 237
 238 impl<'a, S: SigningPubkeyStrategy> InvoiceBuilder<'a, S> {
 239         fn check_amount_msats(invoice_request: &InvoiceRequest) -> Result<u64, Bolt12SemanticError> {
 240                 match invoice_request.amount_msats() {
 241                         Some(amount_msats) => Ok(amount_msats),
 242                         None => match invoice_request.contents.inner.offer.amount() {
 243                                 Some(Amount::Bitcoin { amount_msats }) => {
 244                                         amount_msats.checked_mul(invoice_request.quantity().unwrap_or(1))
 245                                                 .ok_or(Bolt12SemanticError::InvalidAmount)
 246                                 },
 247                                 Some(Amount::Currency { .. }) => Err(Bolt12SemanticError::UnsupportedCurrency),
 248                                 None => Err(Bolt12SemanticError::MissingAmount),
 249                         },
 250                 }
 251         }
 252
 253         fn fields(
 254                 payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, created_at: Duration,
 255                 payment_hash: PaymentHash, amount_msats: u64, signing_pubkey: PublicKey
 256         ) -> InvoiceFields {
 257                 InvoiceFields {
 258                         payment_paths, created_at, relative_expiry: None, payment_hash, amount_msats,
 259                         fallbacks: None, features: Bolt12InvoiceFeatures::empty(), signing_pubkey,
 260                 }
 261         }
 262
 263         fn new(
 264                 invreq_bytes: &'a Vec<u8>, contents: InvoiceContents, signing_pubkey_strategy: S
 265         ) -> Result<Self, Bolt12SemanticError> {
 266                 if contents.fields().payment_paths.is_empty() {
 267                         return Err(Bolt12SemanticError::MissingPaths);
 268                 }
 269
 270                 Ok(Self { invreq_bytes, invoice: contents, signing_pubkey_strategy })
 271         }
 272
 273         /// Sets the [`Bolt12Invoice::relative_expiry`] as seconds since [`Bolt12Invoice::created_at`].
 274         /// Any expiry that has already passed is valid and can be checked for using
 275         /// [`Bolt12Invoice::is_expired`].
 276         ///
 277         /// Successive calls to this method will override the previous setting.
 278         pub fn relative_expiry(mut self, relative_expiry_secs: u32) -> Self {
 279                 let relative_expiry = Duration::from_secs(relative_expiry_secs as u64);
 280                 self.invoice.fields_mut().relative_expiry = Some(relative_expiry);
 281                 self
 282         }
 283
 284         /// Adds a P2WSH address to [`Bolt12Invoice::fallbacks`].
 285         ///
 286         /// Successive calls to this method will add another address. Caller is responsible for not
 287         /// adding duplicate addresses and only calling if capable of receiving to P2WSH addresses.
 288         pub fn fallback_v0_p2wsh(mut self, script_hash: &WScriptHash) -> Self {
 289                 let address = FallbackAddress {
 290                         version: WitnessVersion::V0.to_num(),
 291                         program: Vec::from(&script_hash.into_inner()[..]),
 292                 };
 293                 self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
 294                 self
 295         }
 296
 297         /// Adds a P2WPKH address to [`Bolt12Invoice::fallbacks`].
 298         ///
 299         /// Successive calls to this method will add another address. Caller is responsible for not
 300         /// adding duplicate addresses and only calling if capable of receiving to P2WPKH addresses.
 301         pub fn fallback_v0_p2wpkh(mut self, pubkey_hash: &WPubkeyHash) -> Self {
 302                 let address = FallbackAddress {
 303                         version: WitnessVersion::V0.to_num(),
 304                         program: Vec::from(&pubkey_hash.into_inner()[..]),
 305                 };
 306                 self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
 307                 self
 308         }
 309
 310         /// Adds a P2TR address to [`Bolt12Invoice::fallbacks`].
 311         ///
 312         /// Successive calls to this method will add another address. Caller is responsible for not
 313         /// adding duplicate addresses and only calling if capable of receiving to P2TR addresses.
 314         pub fn fallback_v1_p2tr_tweaked(mut self, output_key: &TweakedPublicKey) -> Self {
 315                 let address = FallbackAddress {
 316                         version: WitnessVersion::V1.to_num(),
 317                         program: Vec::from(&output_key.serialize()[..]),
 318                 };
 319                 self.invoice.fields_mut().fallbacks.get_or_insert_with(Vec::new).push(address);
 320                 self
 321         }
 322
 323         /// Sets [`Bolt12Invoice::features`] to indicate MPP may be used. Otherwise, MPP is disallowed.
 324         pub fn allow_mpp(mut self) -> Self {
 325                 self.invoice.fields_mut().features.set_basic_mpp_optional();
 326                 self
 327         }
 328 }
 329
 330 impl<'a> InvoiceBuilder<'a, ExplicitSigningPubkey> {
 331         /// Builds an unsigned [`Bolt12Invoice`] after checking for valid semantics. It can be signed by
 332         /// [`UnsignedBolt12Invoice::sign`].
 333         pub fn build(self) -> Result<UnsignedBolt12Invoice, Bolt12SemanticError> {
 334                 #[cfg(feature = "std")] {
 335                         if self.invoice.is_offer_or_refund_expired() {
 336                                 return Err(Bolt12SemanticError::AlreadyExpired);
 337                         }
 338                 }
 339
 340                 let InvoiceBuilder { invreq_bytes, invoice, .. } = self;
 341                 Ok(UnsignedBolt12Invoice::new(invreq_bytes, invoice))
 342         }
 343 }
 344
 345 impl<'a> InvoiceBuilder<'a, DerivedSigningPubkey> {
 346         /// Builds a signed [`Bolt12Invoice`] after checking for valid semantics.
 347         pub fn build_and_sign<T: secp256k1::Signing>(
 348                 self, secp_ctx: &Secp256k1<T>
 349         ) -> Result<Bolt12Invoice, Bolt12SemanticError> {
 350                 #[cfg(feature = "std")] {
 351                         if self.invoice.is_offer_or_refund_expired() {
 352                                 return Err(Bolt12SemanticError::AlreadyExpired);
 353                         }
 354                 }
 355
 356                 let InvoiceBuilder {
 357                         invreq_bytes, invoice, signing_pubkey_strategy: DerivedSigningPubkey(keys)
 358                 } = self;
 359                 let unsigned_invoice = UnsignedBolt12Invoice::new(invreq_bytes, invoice);
 360
 361                 let invoice = unsigned_invoice
 362                         .sign::<_, Infallible>(
 363                                 |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
 364                         )
 365                         .unwrap();
 366                 Ok(invoice)
 367         }
 368 }
 369
 370 /// A semantically valid [`Bolt12Invoice`] that hasn't been signed.
 371 pub struct UnsignedBolt12Invoice {
 372         bytes: Vec<u8>,
 373         contents: InvoiceContents,
 374         tagged_hash: TaggedHash,
 375 }
 376
 377 impl UnsignedBolt12Invoice {
 378         fn new(invreq_bytes: &[u8], contents: InvoiceContents) -> Self {
 379                 // Use the invoice_request bytes instead of the invoice_request TLV stream as the latter may
 380                 // have contained unknown TLV records, which are not stored in `InvoiceRequestContents` or
 381                 // `RefundContents`.
 382                 let (_, _, _, invoice_tlv_stream) = contents.as_tlv_stream();
 383                 let invoice_request_bytes = WithoutSignatures(invreq_bytes);
 384                 let unsigned_tlv_stream = (invoice_request_bytes, invoice_tlv_stream);
 385
 386                 let mut bytes = Vec::new();
 387                 unsigned_tlv_stream.write(&mut bytes).unwrap();
 388
 389                 let tagged_hash = TaggedHash::new(SIGNATURE_TAG, &bytes);
 390
 391                 Self { bytes, contents, tagged_hash }
 392         }
 393
 394         /// The public key corresponding to the key needed to sign the invoice.
 395         pub fn signing_pubkey(&self) -> PublicKey {
 396                 self.contents.fields().signing_pubkey
 397         }
 398
 399         /// Signs the invoice using the given function.
 400         ///
 401         /// This is not exported to bindings users as functions aren't currently mapped.
 402         pub fn sign<F, E>(mut self, sign: F) -> Result<Bolt12Invoice, SignError<E>>
 403         where
 404                 F: FnOnce(&Self) -> Result<Signature, E>
 405         {
 406                 let pubkey = self.contents.fields().signing_pubkey;
 407                 let signature = merkle::sign_message(sign, &self, pubkey)?;
 408
 409                 // Append the signature TLV record to the bytes.
 410                 let signature_tlv_stream = SignatureTlvStreamRef {
 411                         signature: Some(&signature),
 412                 };
 413                 signature_tlv_stream.write(&mut self.bytes).unwrap();
 414
 415                 Ok(Bolt12Invoice {
 416                         bytes: self.bytes,
 417                         contents: self.contents,
 418                         signature,
 419                 })
 420         }
 421 }
 422
 423 impl AsRef<TaggedHash> for UnsignedBolt12Invoice {
 424         fn as_ref(&self) -> &TaggedHash {
 425                 &self.tagged_hash
 426         }
 427 }
 428
 429 /// A `Bolt12Invoice` is a payment request, typically corresponding to an [`Offer`] or a [`Refund`].
 430 ///
 431 /// An invoice may be sent in response to an [`InvoiceRequest`] in the case of an offer or sent
 432 /// directly after scanning a refund. It includes all the information needed to pay a recipient.
 433 ///
 434 /// [`Offer`]: crate::offers::offer::Offer
 435 /// [`Refund`]: crate::offers::refund::Refund
 436 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 437 #[derive(Clone, Debug)]
 438 #[cfg_attr(test, derive(PartialEq))]
 439 pub struct Bolt12Invoice {
 440         bytes: Vec<u8>,
 441         contents: InvoiceContents,
 442         signature: Signature,
 443 }
 444
 445 /// The contents of an [`Bolt12Invoice`] for responding to either an [`Offer`] or a [`Refund`].
 446 ///
 447 /// [`Offer`]: crate::offers::offer::Offer
 448 /// [`Refund`]: crate::offers::refund::Refund
 449 #[derive(Clone, Debug)]
 450 #[cfg_attr(test, derive(PartialEq))]
 451 enum InvoiceContents {
 452         /// Contents for an [`Bolt12Invoice`] corresponding to an [`Offer`].
 453         ///
 454         /// [`Offer`]: crate::offers::offer::Offer
 455         ForOffer {
 456                 invoice_request: InvoiceRequestContents,
 457                 fields: InvoiceFields,
 458         },
 459         /// Contents for an [`Bolt12Invoice`] corresponding to a [`Refund`].
 460         ///
 461         /// [`Refund`]: crate::offers::refund::Refund
 462         ForRefund {
 463                 refund: RefundContents,
 464                 fields: InvoiceFields,
 465         },
 466 }
 467
 468 /// Invoice-specific fields for an `invoice` message.
 469 #[derive(Clone, Debug, PartialEq)]
 470 struct InvoiceFields {
 471         payment_paths: Vec<(BlindedPayInfo, BlindedPath)>,
 472         created_at: Duration,
 473         relative_expiry: Option<Duration>,
 474         payment_hash: PaymentHash,
 475         amount_msats: u64,
 476         fallbacks: Option<Vec<FallbackAddress>>,
 477         features: Bolt12InvoiceFeatures,
 478         signing_pubkey: PublicKey,
 479 }
 480
 481 impl Bolt12Invoice {
 482         /// A complete description of the purpose of the originating offer or refund. Intended to be
 483         /// displayed to the user but with the caveat that it has not been verified in any way.
 484         pub fn description(&self) -> PrintableString {
 485                 self.contents.description()
 486         }
 487
 488         /// Paths to the recipient originating from publicly reachable nodes, including information
 489         /// needed for routing payments across them.
 490         ///
 491         /// Blinded paths provide recipient privacy by obfuscating its node id. Note, however, that this
 492         /// privacy is lost if a public node id is used for [`Bolt12Invoice::signing_pubkey`].
 493         ///
 494         /// This is not exported to bindings users as slices with non-reference types cannot be ABI
 495         /// matched in another language.
 496         pub fn payment_paths(&self) -> &[(BlindedPayInfo, BlindedPath)] {
 497                 &self.contents.fields().payment_paths[..]
 498         }
 499
 500         /// Duration since the Unix epoch when the invoice was created.
 501         pub fn created_at(&self) -> Duration {
 502                 self.contents.fields().created_at
 503         }
 504
 505         /// Duration since [`Bolt12Invoice::created_at`] when the invoice has expired and therefore
 506         /// should no longer be paid.
 507         pub fn relative_expiry(&self) -> Duration {
 508                 self.contents.fields().relative_expiry.unwrap_or(DEFAULT_RELATIVE_EXPIRY)
 509         }
 510
 511         /// Whether the invoice has expired.
 512         #[cfg(feature = "std")]
 513         pub fn is_expired(&self) -> bool {
 514                 let absolute_expiry = self.created_at().checked_add(self.relative_expiry());
 515                 match absolute_expiry {
 516                         Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() {
 517                                 Ok(elapsed) => elapsed > seconds_from_epoch,
 518                                 Err(_) => false,
 519                         },
 520                         None => false,
 521                 }
 522         }
 523
 524         /// SHA256 hash of the payment preimage that will be given in return for paying the invoice.
 525         pub fn payment_hash(&self) -> PaymentHash {
 526                 self.contents.fields().payment_hash
 527         }
 528
 529         /// The minimum amount required for a successful payment of the invoice.
 530         pub fn amount_msats(&self) -> u64 {
 531                 self.contents.fields().amount_msats
 532         }
 533
 534         /// Fallback addresses for paying the invoice on-chain, in order of most-preferred to
 535         /// least-preferred.
 536         pub fn fallbacks(&self) -> Vec<Address> {
 537                 let network = match self.network() {
 538                         None => return Vec::new(),
 539                         Some(network) => network,
 540                 };
 541
 542                 let to_valid_address = |address: &FallbackAddress| {
 543                         let version = match WitnessVersion::try_from(address.version) {
 544                                 Ok(version) => version,
 545                                 Err(_) => return None,
 546                         };
 547
 548                         let program = &address.program;
 549                         if program.len() < 2 || program.len() > 40 {
 550                                 return None;
 551                         }
 552
 553                         let address = Address {
 554                                 payload: Payload::WitnessProgram {
 555                                         version,
 556                                         program: address.program.clone(),
 557                                 },
 558                                 network,
 559                         };
 560
 561                         if !address.is_standard() && version == WitnessVersion::V0 {
 562                                 return None;
 563                         }
 564
 565                         Some(address)
 566                 };
 567
 568                 self.contents.fields().fallbacks
 569                         .as_ref()
 570                         .map(|fallbacks| fallbacks.iter().filter_map(to_valid_address).collect())
 571                         .unwrap_or_else(Vec::new)
 572         }
 573
 574         fn network(&self) -> Option<Network> {
 575                 let chain = self.contents.chain();
 576                 if chain == ChainHash::using_genesis_block(Network::Bitcoin) {
 577                         Some(Network::Bitcoin)
 578                 } else if chain == ChainHash::using_genesis_block(Network::Testnet) {
 579                         Some(Network::Testnet)
 580                 } else if chain == ChainHash::using_genesis_block(Network::Signet) {
 581                         Some(Network::Signet)
 582                 } else if chain == ChainHash::using_genesis_block(Network::Regtest) {
 583                         Some(Network::Regtest)
 584                 } else {
 585                         None
 586                 }
 587         }
 588
 589         /// Features pertaining to paying an invoice.
 590         pub fn features(&self) -> &Bolt12InvoiceFeatures {
 591                 &self.contents.fields().features
 592         }
 593
 594         /// The public key corresponding to the key used to sign the invoice.
 595         pub fn signing_pubkey(&self) -> PublicKey {
 596                 self.contents.fields().signing_pubkey
 597         }
 598
 599         /// Signature of the invoice verified using [`Bolt12Invoice::signing_pubkey`].
 600         pub fn signature(&self) -> Signature {
 601                 self.signature
 602         }
 603
 604         /// Hash that was used for signing the invoice.
 605         pub fn signable_hash(&self) -> [u8; 32] {
 606                 merkle::message_digest(SIGNATURE_TAG, &self.bytes).as_ref().clone()
 607         }
 608
 609         /// Verifies that the invoice was for a request or refund created using the given key.
 610         pub fn verify<T: secp256k1::Signing>(
 611                 &self, key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 612         ) -> bool {
 613                 self.contents.verify(TlvStream::new(&self.bytes), key, secp_ctx)
 614         }
 615
 616         #[cfg(test)]
 617         pub(super) fn as_tlv_stream(&self) -> FullInvoiceTlvStreamRef {
 618                 let (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream) =
 619                         self.contents.as_tlv_stream();
 620                 let signature_tlv_stream = SignatureTlvStreamRef {
 621                         signature: Some(&self.signature),
 622                 };
 623                 (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
 624                  signature_tlv_stream)
 625         }
 626 }
 627
 628 impl InvoiceContents {
 629         /// Whether the original offer or refund has expired.
 630         #[cfg(feature = "std")]
 631         fn is_offer_or_refund_expired(&self) -> bool {
 632                 match self {
 633                         InvoiceContents::ForOffer { invoice_request, .. } =>
 634                                 invoice_request.inner.offer.is_expired(),
 635                         InvoiceContents::ForRefund { refund, .. } => refund.is_expired(),
 636                 }
 637         }
 638
 639         fn chain(&self) -> ChainHash {
 640                 match self {
 641                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.chain(),
 642                         InvoiceContents::ForRefund { refund, .. } => refund.chain(),
 643                 }
 644         }
 645
 646         fn description(&self) -> PrintableString {
 647                 match self {
 648                         InvoiceContents::ForOffer { invoice_request, .. } => {
 649                                 invoice_request.inner.offer.description()
 650                         },
 651                         InvoiceContents::ForRefund { refund, .. } => refund.description(),
 652                 }
 653         }
 654
 655         fn fields(&self) -> &InvoiceFields {
 656                 match self {
 657                         InvoiceContents::ForOffer { fields, .. } => fields,
 658                         InvoiceContents::ForRefund { fields, .. } => fields,
 659                 }
 660         }
 661
 662         fn fields_mut(&mut self) -> &mut InvoiceFields {
 663                 match self {
 664                         InvoiceContents::ForOffer { fields, .. } => fields,
 665                         InvoiceContents::ForRefund { fields, .. } => fields,
 666                 }
 667         }
 668
 669         fn verify<T: secp256k1::Signing>(
 670                 &self, tlv_stream: TlvStream<'_>, key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 671         ) -> bool {
 672                 let offer_records = tlv_stream.clone().range(OFFER_TYPES);
 673                 let invreq_records = tlv_stream.range(INVOICE_REQUEST_TYPES).filter(|record| {
 674                         match record.r#type {
 675                                 PAYER_METADATA_TYPE => false, // Should be outside range
 676                                 INVOICE_REQUEST_PAYER_ID_TYPE => !self.derives_keys(),
 677                                 _ => true,
 678                         }
 679                 });
 680                 let tlv_stream = offer_records.chain(invreq_records);
 681
 682                 let (metadata, payer_id, iv_bytes) = match self {
 683                         InvoiceContents::ForOffer { invoice_request, .. } => {
 684                                 (invoice_request.metadata(), invoice_request.payer_id(), INVOICE_REQUEST_IV_BYTES)
 685                         },
 686                         InvoiceContents::ForRefund { refund, .. } => {
 687                                 (refund.metadata(), refund.payer_id(), REFUND_IV_BYTES)
 688                         },
 689                 };
 690
 691                 match signer::verify_metadata(metadata, key, iv_bytes, payer_id, tlv_stream, secp_ctx) {
 692                         Ok(_) => true,
 693                         Err(()) => false,
 694                 }
 695         }
 696
 697         fn derives_keys(&self) -> bool {
 698                 match self {
 699                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.derives_keys(),
 700                         InvoiceContents::ForRefund { refund, .. } => refund.derives_keys(),
 701                 }
 702         }
 703
 704         fn as_tlv_stream(&self) -> PartialInvoiceTlvStreamRef {
 705                 let (payer, offer, invoice_request) = match self {
 706                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.as_tlv_stream(),
 707                         InvoiceContents::ForRefund { refund, .. } => refund.as_tlv_stream(),
 708                 };
 709                 let invoice = self.fields().as_tlv_stream();
 710
 711                 (payer, offer, invoice_request, invoice)
 712         }
 713 }
 714
 715 impl InvoiceFields {
 716         fn as_tlv_stream(&self) -> InvoiceTlvStreamRef {
 717                 let features = {
 718                         if self.features == Bolt12InvoiceFeatures::empty() { None }
 719                         else { Some(&self.features) }
 720                 };
 721
 722                 InvoiceTlvStreamRef {
 723                         paths: Some(Iterable(self.payment_paths.iter().map(|(_, path)| path))),
 724                         blindedpay: Some(Iterable(self.payment_paths.iter().map(|(payinfo, _)| payinfo))),
 725                         created_at: Some(self.created_at.as_secs()),
 726                         relative_expiry: self.relative_expiry.map(|duration| duration.as_secs() as u32),
 727                         payment_hash: Some(&self.payment_hash),
 728                         amount: Some(self.amount_msats),
 729                         fallbacks: self.fallbacks.as_ref(),
 730                         features,
 731                         node_id: Some(&self.signing_pubkey),
 732                 }
 733         }
 734 }
 735
 736 impl Writeable for Bolt12Invoice {
 737         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 738                 WithoutLength(&self.bytes).write(writer)
 739         }
 740 }
 741
 742 impl Writeable for InvoiceContents {
 743         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 744                 self.as_tlv_stream().write(writer)
 745         }
 746 }
 747
 748 impl TryFrom<Vec<u8>> for Bolt12Invoice {
 749         type Error = Bolt12ParseError;
 750
 751         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 752                 let parsed_invoice = ParsedMessage::<FullInvoiceTlvStream>::try_from(bytes)?;
 753                 Bolt12Invoice::try_from(parsed_invoice)
 754         }
 755 }
 756
 757 tlv_stream!(InvoiceTlvStream, InvoiceTlvStreamRef, 160..240, {
 758         (160, paths: (Vec<BlindedPath>, WithoutLength, Iterable<'a, BlindedPathIter<'a>, BlindedPath>)),
 759         (162, blindedpay: (Vec<BlindedPayInfo>, WithoutLength, Iterable<'a, BlindedPayInfoIter<'a>, BlindedPayInfo>)),
 760         (164, created_at: (u64, HighZeroBytesDroppedBigSize)),
 761         (166, relative_expiry: (u32, HighZeroBytesDroppedBigSize)),
 762         (168, payment_hash: PaymentHash),
 763         (170, amount: (u64, HighZeroBytesDroppedBigSize)),
 764         (172, fallbacks: (Vec<FallbackAddress>, WithoutLength)),
 765         (174, features: (Bolt12InvoiceFeatures, WithoutLength)),
 766         (176, node_id: PublicKey),
 767 });
 768
 769 type BlindedPathIter<'a> = core::iter::Map<
 770         core::slice::Iter<'a, (BlindedPayInfo, BlindedPath)>,
 771         for<'r> fn(&'r (BlindedPayInfo, BlindedPath)) -> &'r BlindedPath,
 772 >;
 773
 774 type BlindedPayInfoIter<'a> = core::iter::Map<
 775         core::slice::Iter<'a, (BlindedPayInfo, BlindedPath)>,
 776         for<'r> fn(&'r (BlindedPayInfo, BlindedPath)) -> &'r BlindedPayInfo,
 777 >;
 778
 779 /// Information needed to route a payment across a [`BlindedPath`].
 780 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
 781 pub struct BlindedPayInfo {
 782         /// Base fee charged (in millisatoshi) for the entire blinded path.
 783         pub fee_base_msat: u32,
 784
 785         /// Liquidity fee charged (in millionths of the amount transferred) for the entire blinded path
 786         /// (i.e., 10,000 is 1%).
 787         pub fee_proportional_millionths: u32,
 788
 789         /// Number of blocks subtracted from an incoming HTLC's `cltv_expiry` for the entire blinded
 790         /// path.
 791         pub cltv_expiry_delta: u16,
 792
 793         /// The minimum HTLC value (in millisatoshi) that is acceptable to all channel peers on the
 794         /// blinded path from the introduction node to the recipient, accounting for any fees, i.e., as
 795         /// seen by the recipient.
 796         pub htlc_minimum_msat: u64,
 797
 798         /// The maximum HTLC value (in millisatoshi) that is acceptable to all channel peers on the
 799         /// blinded path from the introduction node to the recipient, accounting for any fees, i.e., as
 800         /// seen by the recipient.
 801         pub htlc_maximum_msat: u64,
 802
 803         /// Features set in `encrypted_data_tlv` for the `encrypted_recipient_data` TLV record in an
 804         /// onion payload.
 805         pub features: BlindedHopFeatures,
 806 }
 807
 808 impl_writeable!(BlindedPayInfo, {
 809         fee_base_msat,
 810         fee_proportional_millionths,
 811         cltv_expiry_delta,
 812         htlc_minimum_msat,
 813         htlc_maximum_msat,
 814         features
 815 });
 816
 817 /// Wire representation for an on-chain fallback address.
 818 #[derive(Clone, Debug, PartialEq)]
 819 pub(super) struct FallbackAddress {
 820         version: u8,
 821         program: Vec<u8>,
 822 }
 823
 824 impl_writeable!(FallbackAddress, { version, program });
 825
 826 type FullInvoiceTlvStream =
 827         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, InvoiceTlvStream, SignatureTlvStream);
 828
 829 #[cfg(test)]
 830 type FullInvoiceTlvStreamRef<'a> = (
 831         PayerTlvStreamRef<'a>,
 832         OfferTlvStreamRef<'a>,
 833         InvoiceRequestTlvStreamRef<'a>,
 834         InvoiceTlvStreamRef<'a>,
 835         SignatureTlvStreamRef<'a>,
 836 );
 837
 838 impl SeekReadable for FullInvoiceTlvStream {
 839         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 840                 let payer = SeekReadable::read(r)?;
 841                 let offer = SeekReadable::read(r)?;
 842                 let invoice_request = SeekReadable::read(r)?;
 843                 let invoice = SeekReadable::read(r)?;
 844                 let signature = SeekReadable::read(r)?;
 845
 846                 Ok((payer, offer, invoice_request, invoice, signature))
 847         }
 848 }
 849
 850 type PartialInvoiceTlvStream =
 851         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, InvoiceTlvStream);
 852
 853 type PartialInvoiceTlvStreamRef<'a> = (
 854         PayerTlvStreamRef<'a>,
 855         OfferTlvStreamRef<'a>,
 856         InvoiceRequestTlvStreamRef<'a>,
 857         InvoiceTlvStreamRef<'a>,
 858 );
 859
 860 impl TryFrom<ParsedMessage<FullInvoiceTlvStream>> for Bolt12Invoice {
 861         type Error = Bolt12ParseError;
 862
 863         fn try_from(invoice: ParsedMessage<FullInvoiceTlvStream>) -> Result<Self, Self::Error> {
 864                 let ParsedMessage { bytes, tlv_stream } = invoice;
 865                 let (
 866                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
 867                         SignatureTlvStream { signature },
 868                 ) = tlv_stream;
 869                 let contents = InvoiceContents::try_from(
 870                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream)
 871                 )?;
 872
 873                 let signature = match signature {
 874                         None => return Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
 875                         Some(signature) => signature,
 876                 };
 877                 let pubkey = contents.fields().signing_pubkey;
 878                 merkle::verify_signature(&signature, SIGNATURE_TAG, &bytes, pubkey)?;
 879
 880                 Ok(Bolt12Invoice { bytes, contents, signature })
 881         }
 882 }
 883
 884 impl TryFrom<PartialInvoiceTlvStream> for InvoiceContents {
 885         type Error = Bolt12SemanticError;
 886
 887         fn try_from(tlv_stream: PartialInvoiceTlvStream) -> Result<Self, Self::Error> {
 888                 let (
 889                         payer_tlv_stream,
 890                         offer_tlv_stream,
 891                         invoice_request_tlv_stream,
 892                         InvoiceTlvStream {
 893                                 paths, blindedpay, created_at, relative_expiry, payment_hash, amount, fallbacks,
 894                                 features, node_id,
 895                         },
 896                 ) = tlv_stream;
 897
 898                 let payment_paths = match (blindedpay, paths) {
 899                         (_, None) => return Err(Bolt12SemanticError::MissingPaths),
 900                         (None, _) => return Err(Bolt12SemanticError::InvalidPayInfo),
 901                         (_, Some(paths)) if paths.is_empty() => return Err(Bolt12SemanticError::MissingPaths),
 902                         (Some(blindedpay), Some(paths)) if paths.len() != blindedpay.len() => {
 903                                 return Err(Bolt12SemanticError::InvalidPayInfo);
 904                         },
 905                         (Some(blindedpay), Some(paths)) => {
 906                                 blindedpay.into_iter().zip(paths.into_iter()).collect::<Vec<_>>()
 907                         },
 908                 };
 909
 910                 let created_at = match created_at {
 911                         None => return Err(Bolt12SemanticError::MissingCreationTime),
 912                         Some(timestamp) => Duration::from_secs(timestamp),
 913                 };
 914
 915                 let relative_expiry = relative_expiry
 916                         .map(Into::<u64>::into)
 917                         .map(Duration::from_secs);
 918
 919                 let payment_hash = match payment_hash {
 920                         None => return Err(Bolt12SemanticError::MissingPaymentHash),
 921                         Some(payment_hash) => payment_hash,
 922                 };
 923
 924                 let amount_msats = match amount {
 925                         None => return Err(Bolt12SemanticError::MissingAmount),
 926                         Some(amount) => amount,
 927                 };
 928
 929                 let features = features.unwrap_or_else(Bolt12InvoiceFeatures::empty);
 930
 931                 let signing_pubkey = match node_id {
 932                         None => return Err(Bolt12SemanticError::MissingSigningPubkey),
 933                         Some(node_id) => node_id,
 934                 };
 935
 936                 let fields = InvoiceFields {
 937                         payment_paths, created_at, relative_expiry, payment_hash, amount_msats, fallbacks,
 938                         features, signing_pubkey,
 939                 };
 940
 941                 match offer_tlv_stream.node_id {
 942                         Some(expected_signing_pubkey) => {
 943                                 if fields.signing_pubkey != expected_signing_pubkey {
 944                                         return Err(Bolt12SemanticError::InvalidSigningPubkey);
 945                                 }
 946
 947                                 let invoice_request = InvoiceRequestContents::try_from(
 948                                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 949                                 )?;
 950                                 Ok(InvoiceContents::ForOffer { invoice_request, fields })
 951                         },
 952                         None => {
 953                                 let refund = RefundContents::try_from(
 954                                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 955                                 )?;
 956                                 Ok(InvoiceContents::ForRefund { refund, fields })
 957                         },
 958                 }
 959         }
 960 }
 961
 962 #[cfg(test)]
 963 mod tests {
 964         use super::{Bolt12Invoice, DEFAULT_RELATIVE_EXPIRY, FallbackAddress, FullInvoiceTlvStreamRef, InvoiceTlvStreamRef, SIGNATURE_TAG};
 965
 966         use bitcoin::blockdata::script::Script;
 967         use bitcoin::hashes::Hash;
 968         use bitcoin::network::constants::Network;
 969         use bitcoin::secp256k1::{Message, Secp256k1, XOnlyPublicKey, self};
 970         use bitcoin::util::address::{Address, Payload, WitnessVersion};
 971         use bitcoin::util::schnorr::TweakedPublicKey;
 972         use core::convert::TryFrom;
 973         use core::time::Duration;
 974         use crate::blinded_path::{BlindedHop, BlindedPath};
 975         use crate::sign::KeyMaterial;
 976         use crate::ln::features::Bolt12InvoiceFeatures;
 977         use crate::ln::inbound_payment::ExpandedKey;
 978         use crate::ln::msgs::DecodeError;
 979         use crate::offers::invoice_request::InvoiceRequestTlvStreamRef;
 980         use crate::offers::merkle::{SignError, SignatureTlvStreamRef, self};
 981         use crate::offers::offer::{OfferBuilder, OfferTlvStreamRef, Quantity};
 982         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
 983         use crate::offers::payer::PayerTlvStreamRef;
 984         use crate::offers::refund::RefundBuilder;
 985         use crate::offers::test_utils::*;
 986         use crate::util::ser::{BigSize, Iterable, Writeable};
 987         use crate::util::string::PrintableString;
 988
 989         trait ToBytes {
 990                 fn to_bytes(&self) -> Vec<u8>;
 991         }
 992
 993         impl<'a> ToBytes for FullInvoiceTlvStreamRef<'a> {
 994                 fn to_bytes(&self) -> Vec<u8> {
 995                         let mut buffer = Vec::new();
 996                         self.0.write(&mut buffer).unwrap();
 997                         self.1.write(&mut buffer).unwrap();
 998                         self.2.write(&mut buffer).unwrap();
 999                         self.3.write(&mut buffer).unwrap();
1000                         self.4.write(&mut buffer).unwrap();
1001                         buffer
1002                 }
1003         }
1004
1005         #[test]
1006         fn builds_invoice_for_offer_with_defaults() {
1007                 let payment_paths = payment_paths();
1008                 let payment_hash = payment_hash();
1009                 let now = now();
1010                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1011                         .amount_msats(1000)
1012                         .build().unwrap()
1013                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1014                         .build().unwrap()
1015                         .sign(payer_sign).unwrap()
1016                         .respond_with_no_std(payment_paths.clone(), payment_hash, now).unwrap()
1017                         .build().unwrap()
1018                         .sign(recipient_sign).unwrap();
1019
1020                 let mut buffer = Vec::new();
1021                 invoice.write(&mut buffer).unwrap();
1022
1023                 assert_eq!(invoice.bytes, buffer.as_slice());
1024                 assert_eq!(invoice.description(), PrintableString("foo"));
1025                 assert_eq!(invoice.payment_paths(), payment_paths.as_slice());
1026                 assert_eq!(invoice.created_at(), now);
1027                 assert_eq!(invoice.relative_expiry(), DEFAULT_RELATIVE_EXPIRY);
1028                 #[cfg(feature = "std")]
1029                 assert!(!invoice.is_expired());
1030                 assert_eq!(invoice.payment_hash(), payment_hash);
1031                 assert_eq!(invoice.amount_msats(), 1000);
1032                 assert_eq!(invoice.fallbacks(), vec![]);
1033                 assert_eq!(invoice.features(), &Bolt12InvoiceFeatures::empty());
1034                 assert_eq!(invoice.signing_pubkey(), recipient_pubkey());
1035                 assert!(
1036                         merkle::verify_signature(
1037                                 &invoice.signature, SIGNATURE_TAG, &invoice.bytes, recipient_pubkey()
1038                         ).is_ok()
1039                 );
1040
1041                 let digest = Message::from_slice(&invoice.signable_hash()).unwrap();
1042                 let pubkey = recipient_pubkey().into();
1043                 let secp_ctx = Secp256k1::verification_only();
1044                 assert!(secp_ctx.verify_schnorr(&invoice.signature, &digest, &pubkey).is_ok());
1045
1046                 assert_eq!(
1047                         invoice.as_tlv_stream(),
1048                         (
1049                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
1050                                 OfferTlvStreamRef {
1051                                         chains: None,
1052                                         metadata: None,
1053                                         currency: None,
1054                                         amount: Some(1000),
1055                                         description: Some(&String::from("foo")),
1056                                         features: None,
1057                                         absolute_expiry: None,
1058                                         paths: None,
1059                                         issuer: None,
1060                                         quantity_max: None,
1061                                         node_id: Some(&recipient_pubkey()),
1062                                 },
1063                                 InvoiceRequestTlvStreamRef {
1064                                         chain: None,
1065                                         amount: None,
1066                                         features: None,
1067                                         quantity: None,
1068                                         payer_id: Some(&payer_pubkey()),
1069                                         payer_note: None,
1070                                 },
1071                                 InvoiceTlvStreamRef {
1072                                         paths: Some(Iterable(payment_paths.iter().map(|(_, path)| path))),
1073                                         blindedpay: Some(Iterable(payment_paths.iter().map(|(payinfo, _)| payinfo))),
1074                                         created_at: Some(now.as_secs()),
1075                                         relative_expiry: None,
1076                                         payment_hash: Some(&payment_hash),
1077                                         amount: Some(1000),
1078                                         fallbacks: None,
1079                                         features: None,
1080                                         node_id: Some(&recipient_pubkey()),
1081                                 },
1082                                 SignatureTlvStreamRef { signature: Some(&invoice.signature()) },
1083                         ),
1084                 );
1085
1086                 if let Err(e) = Bolt12Invoice::try_from(buffer) {
1087                         panic!("error parsing invoice: {:?}", e);
1088                 }
1089         }
1090
1091         #[test]
1092         fn builds_invoice_for_refund_with_defaults() {
1093                 let payment_paths = payment_paths();
1094                 let payment_hash = payment_hash();
1095                 let now = now();
1096                 let invoice = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
1097                         .build().unwrap()
1098                         .respond_with_no_std(payment_paths.clone(), payment_hash, recipient_pubkey(), now)
1099                         .unwrap()
1100                         .build().unwrap()
1101                         .sign(recipient_sign).unwrap();
1102
1103                 let mut buffer = Vec::new();
1104                 invoice.write(&mut buffer).unwrap();
1105
1106                 assert_eq!(invoice.bytes, buffer.as_slice());
1107                 assert_eq!(invoice.description(), PrintableString("foo"));
1108                 assert_eq!(invoice.payment_paths(), payment_paths.as_slice());
1109                 assert_eq!(invoice.created_at(), now);
1110                 assert_eq!(invoice.relative_expiry(), DEFAULT_RELATIVE_EXPIRY);
1111                 #[cfg(feature = "std")]
1112                 assert!(!invoice.is_expired());
1113                 assert_eq!(invoice.payment_hash(), payment_hash);
1114                 assert_eq!(invoice.amount_msats(), 1000);
1115                 assert_eq!(invoice.fallbacks(), vec![]);
1116                 assert_eq!(invoice.features(), &Bolt12InvoiceFeatures::empty());
1117                 assert_eq!(invoice.signing_pubkey(), recipient_pubkey());
1118                 assert!(
1119                         merkle::verify_signature(
1120                                 &invoice.signature, SIGNATURE_TAG, &invoice.bytes, recipient_pubkey()
1121                         ).is_ok()
1122                 );
1123
1124                 assert_eq!(
1125                         invoice.as_tlv_stream(),
1126                         (
1127                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
1128                                 OfferTlvStreamRef {
1129                                         chains: None,
1130                                         metadata: None,
1131                                         currency: None,
1132                                         amount: None,
1133                                         description: Some(&String::from("foo")),
1134                                         features: None,
1135                                         absolute_expiry: None,
1136                                         paths: None,
1137                                         issuer: None,
1138                                         quantity_max: None,
1139                                         node_id: None,
1140                                 },
1141                                 InvoiceRequestTlvStreamRef {
1142                                         chain: None,
1143                                         amount: Some(1000),
1144                                         features: None,
1145                                         quantity: None,
1146                                         payer_id: Some(&payer_pubkey()),
1147                                         payer_note: None,
1148                                 },
1149                                 InvoiceTlvStreamRef {
1150                                         paths: Some(Iterable(payment_paths.iter().map(|(_, path)| path))),
1151                                         blindedpay: Some(Iterable(payment_paths.iter().map(|(payinfo, _)| payinfo))),
1152                                         created_at: Some(now.as_secs()),
1153                                         relative_expiry: None,
1154                                         payment_hash: Some(&payment_hash),
1155                                         amount: Some(1000),
1156                                         fallbacks: None,
1157                                         features: None,
1158                                         node_id: Some(&recipient_pubkey()),
1159                                 },
1160                                 SignatureTlvStreamRef { signature: Some(&invoice.signature()) },
1161                         ),
1162                 );
1163
1164                 if let Err(e) = Bolt12Invoice::try_from(buffer) {
1165                         panic!("error parsing invoice: {:?}", e);
1166                 }
1167         }
1168
1169         #[cfg(feature = "std")]
1170         #[test]
1171         fn builds_invoice_from_offer_with_expiration() {
1172                 let future_expiry = Duration::from_secs(u64::max_value());
1173                 let past_expiry = Duration::from_secs(0);
1174
1175                 if let Err(e) = OfferBuilder::new("foo".into(), recipient_pubkey())
1176                         .amount_msats(1000)
1177                         .absolute_expiry(future_expiry)
1178                         .build().unwrap()
1179                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1180                         .build().unwrap()
1181                         .sign(payer_sign).unwrap()
1182                         .respond_with(payment_paths(), payment_hash())
1183                         .unwrap()
1184                         .build()
1185                 {
1186                         panic!("error building invoice: {:?}", e);
1187                 }
1188
1189                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1190                         .amount_msats(1000)
1191                         .absolute_expiry(past_expiry)
1192                         .build().unwrap()
1193                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1194                         .build_unchecked()
1195                         .sign(payer_sign).unwrap()
1196                         .respond_with(payment_paths(), payment_hash())
1197                         .unwrap()
1198                         .build()
1199                 {
1200                         Ok(_) => panic!("expected error"),
1201                         Err(e) => assert_eq!(e, Bolt12SemanticError::AlreadyExpired),
1202                 }
1203         }
1204
1205         #[cfg(feature = "std")]
1206         #[test]
1207         fn builds_invoice_from_refund_with_expiration() {
1208                 let future_expiry = Duration::from_secs(u64::max_value());
1209                 let past_expiry = Duration::from_secs(0);
1210
1211                 if let Err(e) = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
1212                         .absolute_expiry(future_expiry)
1213                         .build().unwrap()
1214                         .respond_with(payment_paths(), payment_hash(), recipient_pubkey())
1215                         .unwrap()
1216                         .build()
1217                 {
1218                         panic!("error building invoice: {:?}", e);
1219                 }
1220
1221                 match RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
1222                         .absolute_expiry(past_expiry)
1223                         .build().unwrap()
1224                         .respond_with(payment_paths(), payment_hash(), recipient_pubkey())
1225                         .unwrap()
1226                         .build()
1227                 {
1228                         Ok(_) => panic!("expected error"),
1229                         Err(e) => assert_eq!(e, Bolt12SemanticError::AlreadyExpired),
1230                 }
1231         }
1232
1233         #[test]
1234         fn builds_invoice_from_offer_using_derived_keys() {
1235                 let desc = "foo".to_string();
1236                 let node_id = recipient_pubkey();
1237                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1238                 let entropy = FixedEntropy {};
1239                 let secp_ctx = Secp256k1::new();
1240
1241                 let blinded_path = BlindedPath {
1242                         introduction_node_id: pubkey(40),
1243                         blinding_point: pubkey(41),
1244                         blinded_hops: vec![
1245                                 BlindedHop { blinded_node_id: pubkey(42), encrypted_payload: vec![0; 43] },
1246                                 BlindedHop { blinded_node_id: node_id, encrypted_payload: vec![0; 44] },
1247                         ],
1248                 };
1249
1250                 let offer = OfferBuilder
1251                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1252                         .amount_msats(1000)
1253                         .path(blinded_path)
1254                         .build().unwrap();
1255                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1256                         .build().unwrap()
1257                         .sign(payer_sign).unwrap();
1258
1259                 if let Err(e) = invoice_request
1260                         .verify_and_respond_using_derived_keys_no_std(
1261                                 payment_paths(), payment_hash(), now(), &expanded_key, &secp_ctx
1262                         )
1263                         .unwrap()
1264                         .build_and_sign(&secp_ctx)
1265                 {
1266                         panic!("error building invoice: {:?}", e);
1267                 }
1268
1269                 let expanded_key = ExpandedKey::new(&KeyMaterial([41; 32]));
1270                 match invoice_request.verify_and_respond_using_derived_keys_no_std(
1271                         payment_paths(), payment_hash(), now(), &expanded_key, &secp_ctx
1272                 ) {
1273                         Ok(_) => panic!("expected error"),
1274                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidMetadata),
1275                 }
1276
1277                 let desc = "foo".to_string();
1278                 let offer = OfferBuilder
1279                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1280                         .amount_msats(1000)
1281                         .build().unwrap();
1282                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1283                         .build().unwrap()
1284                         .sign(payer_sign).unwrap();
1285
1286                 match invoice_request.verify_and_respond_using_derived_keys_no_std(
1287                         payment_paths(), payment_hash(), now(), &expanded_key, &secp_ctx
1288                 ) {
1289                         Ok(_) => panic!("expected error"),
1290                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidMetadata),
1291                 }
1292         }
1293
1294         #[test]
1295         fn builds_invoice_from_refund_using_derived_keys() {
1296                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1297                 let entropy = FixedEntropy {};
1298                 let secp_ctx = Secp256k1::new();
1299
1300                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
1301                         .build().unwrap();
1302
1303                 if let Err(e) = refund
1304                         .respond_using_derived_keys_no_std(
1305                                 payment_paths(), payment_hash(), now(), &expanded_key, &entropy
1306                         )
1307                         .unwrap()
1308                         .build_and_sign(&secp_ctx)
1309                 {
1310                         panic!("error building invoice: {:?}", e);
1311                 }
1312         }
1313
1314         #[test]
1315         fn builds_invoice_with_relative_expiry() {
1316                 let now = now();
1317                 let one_hour = Duration::from_secs(3600);
1318
1319                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1320                         .amount_msats(1000)
1321                         .build().unwrap()
1322                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1323                         .build().unwrap()
1324                         .sign(payer_sign).unwrap()
1325                         .respond_with_no_std(payment_paths(), payment_hash(), now).unwrap()
1326                         .relative_expiry(one_hour.as_secs() as u32)
1327                         .build().unwrap()
1328                         .sign(recipient_sign).unwrap();
1329                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1330                 #[cfg(feature = "std")]
1331                 assert!(!invoice.is_expired());
1332                 assert_eq!(invoice.relative_expiry(), one_hour);
1333                 assert_eq!(tlv_stream.relative_expiry, Some(one_hour.as_secs() as u32));
1334
1335                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1336                         .amount_msats(1000)
1337                         .build().unwrap()
1338                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1339                         .build().unwrap()
1340                         .sign(payer_sign).unwrap()
1341                         .respond_with_no_std(payment_paths(), payment_hash(), now - one_hour).unwrap()
1342                         .relative_expiry(one_hour.as_secs() as u32 - 1)
1343                         .build().unwrap()
1344                         .sign(recipient_sign).unwrap();
1345                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1346                 #[cfg(feature = "std")]
1347                 assert!(invoice.is_expired());
1348                 assert_eq!(invoice.relative_expiry(), one_hour - Duration::from_secs(1));
1349                 assert_eq!(tlv_stream.relative_expiry, Some(one_hour.as_secs() as u32 - 1));
1350         }
1351
1352         #[test]
1353         fn builds_invoice_with_amount_from_request() {
1354                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1355                         .amount_msats(1000)
1356                         .build().unwrap()
1357                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1358                         .amount_msats(1001).unwrap()
1359                         .build().unwrap()
1360                         .sign(payer_sign).unwrap()
1361                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1362                         .build().unwrap()
1363                         .sign(recipient_sign).unwrap();
1364                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1365                 assert_eq!(invoice.amount_msats(), 1001);
1366                 assert_eq!(tlv_stream.amount, Some(1001));
1367         }
1368
1369         #[test]
1370         fn builds_invoice_with_quantity_from_request() {
1371                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1372                         .amount_msats(1000)
1373                         .supported_quantity(Quantity::Unbounded)
1374                         .build().unwrap()
1375                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1376                         .quantity(2).unwrap()
1377                         .build().unwrap()
1378                         .sign(payer_sign).unwrap()
1379                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1380                         .build().unwrap()
1381                         .sign(recipient_sign).unwrap();
1382                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1383                 assert_eq!(invoice.amount_msats(), 2000);
1384                 assert_eq!(tlv_stream.amount, Some(2000));
1385
1386                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1387                         .amount_msats(1000)
1388                         .supported_quantity(Quantity::Unbounded)
1389                         .build().unwrap()
1390                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1391                         .quantity(u64::max_value()).unwrap()
1392                         .build_unchecked()
1393                         .sign(payer_sign).unwrap()
1394                         .respond_with_no_std(payment_paths(), payment_hash(), now())
1395                 {
1396                         Ok(_) => panic!("expected error"),
1397                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1398                 }
1399         }
1400
1401         #[test]
1402         fn builds_invoice_with_fallback_address() {
1403                 let script = Script::new();
1404                 let pubkey = bitcoin::util::key::PublicKey::new(recipient_pubkey());
1405                 let x_only_pubkey = XOnlyPublicKey::from_keypair(&recipient_keys()).0;
1406                 let tweaked_pubkey = TweakedPublicKey::dangerous_assume_tweaked(x_only_pubkey);
1407
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                         .fallback_v0_p2wsh(&script.wscript_hash())
1416                         .fallback_v0_p2wpkh(&pubkey.wpubkey_hash().unwrap())
1417                         .fallback_v1_p2tr_tweaked(&tweaked_pubkey)
1418                         .build().unwrap()
1419                         .sign(recipient_sign).unwrap();
1420                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1421                 assert_eq!(
1422                         invoice.fallbacks(),
1423                         vec![
1424                                 Address::p2wsh(&script, Network::Bitcoin),
1425                                 Address::p2wpkh(&pubkey, Network::Bitcoin).unwrap(),
1426                                 Address::p2tr_tweaked(tweaked_pubkey, Network::Bitcoin),
1427                         ],
1428                 );
1429                 assert_eq!(
1430                         tlv_stream.fallbacks,
1431                         Some(&vec![
1432                                 FallbackAddress {
1433                                         version: WitnessVersion::V0.to_num(),
1434                                         program: Vec::from(&script.wscript_hash().into_inner()[..]),
1435                                 },
1436                                 FallbackAddress {
1437                                         version: WitnessVersion::V0.to_num(),
1438                                         program: Vec::from(&pubkey.wpubkey_hash().unwrap().into_inner()[..]),
1439                                 },
1440                                 FallbackAddress {
1441                                         version: WitnessVersion::V1.to_num(),
1442                                         program: Vec::from(&tweaked_pubkey.serialize()[..]),
1443                                 },
1444                         ])
1445                 );
1446         }
1447
1448         #[test]
1449         fn builds_invoice_with_allow_mpp() {
1450                 let mut features = Bolt12InvoiceFeatures::empty();
1451                 features.set_basic_mpp_optional();
1452
1453                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1454                         .amount_msats(1000)
1455                         .build().unwrap()
1456                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1457                         .build().unwrap()
1458                         .sign(payer_sign).unwrap()
1459                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1460                         .allow_mpp()
1461                         .build().unwrap()
1462                         .sign(recipient_sign).unwrap();
1463                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1464                 assert_eq!(invoice.features(), &features);
1465                 assert_eq!(tlv_stream.features, Some(&features));
1466         }
1467
1468         #[test]
1469         fn fails_signing_invoice() {
1470                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1471                         .amount_msats(1000)
1472                         .build().unwrap()
1473                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1474                         .build().unwrap()
1475                         .sign(payer_sign).unwrap()
1476                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1477                         .build().unwrap()
1478                         .sign(|_| Err(()))
1479                 {
1480                         Ok(_) => panic!("expected error"),
1481                         Err(e) => assert_eq!(e, SignError::Signing(())),
1482                 }
1483
1484                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1485                         .amount_msats(1000)
1486                         .build().unwrap()
1487                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1488                         .build().unwrap()
1489                         .sign(payer_sign).unwrap()
1490                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1491                         .build().unwrap()
1492                         .sign(payer_sign)
1493                 {
1494                         Ok(_) => panic!("expected error"),
1495                         Err(e) => assert_eq!(e, SignError::Verification(secp256k1::Error::InvalidSignature)),
1496                 }
1497         }
1498
1499         #[test]
1500         fn parses_invoice_with_payment_paths() {
1501                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1502                         .amount_msats(1000)
1503                         .build().unwrap()
1504                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1505                         .build().unwrap()
1506                         .sign(payer_sign).unwrap()
1507                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1508                         .build().unwrap()
1509                         .sign(recipient_sign).unwrap();
1510
1511                 let mut buffer = Vec::new();
1512                 invoice.write(&mut buffer).unwrap();
1513
1514                 if let Err(e) = Bolt12Invoice::try_from(buffer) {
1515                         panic!("error parsing invoice: {:?}", e);
1516                 }
1517
1518                 let mut tlv_stream = invoice.as_tlv_stream();
1519                 tlv_stream.3.paths = None;
1520
1521                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
1522                         Ok(_) => panic!("expected error"),
1523                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPaths)),
1524                 }
1525
1526                 let mut tlv_stream = invoice.as_tlv_stream();
1527                 tlv_stream.3.blindedpay = None;
1528
1529                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
1530                         Ok(_) => panic!("expected error"),
1531                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidPayInfo)),
1532                 }
1533
1534                 let empty_payment_paths = vec![];
1535                 let mut tlv_stream = invoice.as_tlv_stream();
1536                 tlv_stream.3.paths = Some(Iterable(empty_payment_paths.iter().map(|(_, path)| path)));
1537
1538                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
1539                         Ok(_) => panic!("expected error"),
1540                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPaths)),
1541                 }
1542
1543                 let mut payment_paths = payment_paths();
1544                 payment_paths.pop();
1545                 let mut tlv_stream = invoice.as_tlv_stream();
1546                 tlv_stream.3.blindedpay = Some(Iterable(payment_paths.iter().map(|(payinfo, _)| payinfo)));
1547
1548                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
1549                         Ok(_) => panic!("expected error"),
1550                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidPayInfo)),
1551                 }
1552         }
1553
1554         #[test]
1555         fn parses_invoice_with_created_at() {
1556                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1557                         .amount_msats(1000)
1558                         .build().unwrap()
1559                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1560                         .build().unwrap()
1561                         .sign(payer_sign).unwrap()
1562                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1563                         .build().unwrap()
1564                         .sign(recipient_sign).unwrap();
1565
1566                 let mut buffer = Vec::new();
1567                 invoice.write(&mut buffer).unwrap();
1568
1569                 if let Err(e) = Bolt12Invoice::try_from(buffer) {
1570                         panic!("error parsing invoice: {:?}", e);
1571                 }
1572
1573                 let mut tlv_stream = invoice.as_tlv_stream();
1574                 tlv_stream.3.created_at = None;
1575
1576                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
1577                         Ok(_) => panic!("expected error"),
1578                         Err(e) => {
1579                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingCreationTime));
1580                         },
1581                 }
1582         }
1583
1584         #[test]
1585         fn parses_invoice_with_relative_expiry() {
1586                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1587                         .amount_msats(1000)
1588                         .build().unwrap()
1589                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1590                         .build().unwrap()
1591                         .sign(payer_sign).unwrap()
1592                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1593                         .relative_expiry(3600)
1594                         .build().unwrap()
1595                         .sign(recipient_sign).unwrap();
1596
1597                 let mut buffer = Vec::new();
1598                 invoice.write(&mut buffer).unwrap();
1599
1600                 match Bolt12Invoice::try_from(buffer) {
1601                         Ok(invoice) => assert_eq!(invoice.relative_expiry(), Duration::from_secs(3600)),
1602                         Err(e) => panic!("error parsing invoice: {:?}", e),
1603                 }
1604         }
1605
1606         #[test]
1607         fn parses_invoice_with_payment_hash() {
1608                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1609                         .amount_msats(1000)
1610                         .build().unwrap()
1611                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1612                         .build().unwrap()
1613                         .sign(payer_sign).unwrap()
1614                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1615                         .build().unwrap()
1616                         .sign(recipient_sign).unwrap();
1617
1618                 let mut buffer = Vec::new();
1619                 invoice.write(&mut buffer).unwrap();
1620
1621                 if let Err(e) = Bolt12Invoice::try_from(buffer) {
1622                         panic!("error parsing invoice: {:?}", e);
1623                 }
1624
1625                 let mut tlv_stream = invoice.as_tlv_stream();
1626                 tlv_stream.3.payment_hash = None;
1627
1628                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
1629                         Ok(_) => panic!("expected error"),
1630                         Err(e) => {
1631                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPaymentHash));
1632                         },
1633                 }
1634         }
1635
1636         #[test]
1637         fn parses_invoice_with_amount() {
1638                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1639                         .amount_msats(1000)
1640                         .build().unwrap()
1641                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1642                         .build().unwrap()
1643                         .sign(payer_sign).unwrap()
1644                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1645                         .build().unwrap()
1646                         .sign(recipient_sign).unwrap();
1647
1648                 let mut buffer = Vec::new();
1649                 invoice.write(&mut buffer).unwrap();
1650
1651                 if let Err(e) = Bolt12Invoice::try_from(buffer) {
1652                         panic!("error parsing invoice: {:?}", e);
1653                 }
1654
1655                 let mut tlv_stream = invoice.as_tlv_stream();
1656                 tlv_stream.3.amount = None;
1657
1658                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
1659                         Ok(_) => panic!("expected error"),
1660                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1661                 }
1662         }
1663
1664         #[test]
1665         fn parses_invoice_with_allow_mpp() {
1666                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1667                         .amount_msats(1000)
1668                         .build().unwrap()
1669                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1670                         .build().unwrap()
1671                         .sign(payer_sign).unwrap()
1672                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1673                         .allow_mpp()
1674                         .build().unwrap()
1675                         .sign(recipient_sign).unwrap();
1676
1677                 let mut buffer = Vec::new();
1678                 invoice.write(&mut buffer).unwrap();
1679
1680                 match Bolt12Invoice::try_from(buffer) {
1681                         Ok(invoice) => {
1682                                 let mut features = Bolt12InvoiceFeatures::empty();
1683                                 features.set_basic_mpp_optional();
1684                                 assert_eq!(invoice.features(), &features);
1685                         },
1686                         Err(e) => panic!("error parsing invoice: {:?}", e),
1687                 }
1688         }
1689
1690         #[test]
1691         fn parses_invoice_with_fallback_address() {
1692                 let script = Script::new();
1693                 let pubkey = bitcoin::util::key::PublicKey::new(recipient_pubkey());
1694                 let x_only_pubkey = XOnlyPublicKey::from_keypair(&recipient_keys()).0;
1695                 let tweaked_pubkey = TweakedPublicKey::dangerous_assume_tweaked(x_only_pubkey);
1696
1697                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1698                         .amount_msats(1000)
1699                         .build().unwrap();
1700                 let invoice_request = offer
1701                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1702                         .build().unwrap()
1703                         .sign(payer_sign).unwrap();
1704                 let mut invoice_builder = invoice_request
1705                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1706                         .fallback_v0_p2wsh(&script.wscript_hash())
1707                         .fallback_v0_p2wpkh(&pubkey.wpubkey_hash().unwrap())
1708                         .fallback_v1_p2tr_tweaked(&tweaked_pubkey);
1709
1710                 // Only standard addresses will be included.
1711                 let fallbacks = invoice_builder.invoice.fields_mut().fallbacks.as_mut().unwrap();
1712                 // Non-standard addresses
1713                 fallbacks.push(FallbackAddress { version: 1, program: vec![0u8; 41] });
1714                 fallbacks.push(FallbackAddress { version: 2, program: vec![0u8; 1] });
1715                 fallbacks.push(FallbackAddress { version: 17, program: vec![0u8; 40] });
1716                 // Standard address
1717                 fallbacks.push(FallbackAddress { version: 1, program: vec![0u8; 33] });
1718                 fallbacks.push(FallbackAddress { version: 2, program: vec![0u8; 40] });
1719
1720                 let invoice = invoice_builder.build().unwrap().sign(recipient_sign).unwrap();
1721                 let mut buffer = Vec::new();
1722                 invoice.write(&mut buffer).unwrap();
1723
1724                 match Bolt12Invoice::try_from(buffer) {
1725                         Ok(invoice) => {
1726                                 assert_eq!(
1727                                         invoice.fallbacks(),
1728                                         vec![
1729                                                 Address::p2wsh(&script, Network::Bitcoin),
1730                                                 Address::p2wpkh(&pubkey, Network::Bitcoin).unwrap(),
1731                                                 Address::p2tr_tweaked(tweaked_pubkey, Network::Bitcoin),
1732                                                 Address {
1733                                                         payload: Payload::WitnessProgram {
1734                                                                 version: WitnessVersion::V1,
1735                                                                 program: vec![0u8; 33],
1736                                                         },
1737                                                         network: Network::Bitcoin,
1738                                                 },
1739                                                 Address {
1740                                                         payload: Payload::WitnessProgram {
1741                                                                 version: WitnessVersion::V2,
1742                                                                 program: vec![0u8; 40],
1743                                                         },
1744                                                         network: Network::Bitcoin,
1745                                                 },
1746                                         ],
1747                                 );
1748                         },
1749                         Err(e) => panic!("error parsing invoice: {:?}", e),
1750                 }
1751         }
1752
1753         #[test]
1754         fn parses_invoice_with_node_id() {
1755                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1756                         .amount_msats(1000)
1757                         .build().unwrap()
1758                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1759                         .build().unwrap()
1760                         .sign(payer_sign).unwrap()
1761                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1762                         .build().unwrap()
1763                         .sign(recipient_sign).unwrap();
1764
1765                 let mut buffer = Vec::new();
1766                 invoice.write(&mut buffer).unwrap();
1767
1768                 if let Err(e) = Bolt12Invoice::try_from(buffer) {
1769                         panic!("error parsing invoice: {:?}", e);
1770                 }
1771
1772                 let mut tlv_stream = invoice.as_tlv_stream();
1773                 tlv_stream.3.node_id = None;
1774
1775                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
1776                         Ok(_) => panic!("expected error"),
1777                         Err(e) => {
1778                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1779                         },
1780                 }
1781
1782                 let invalid_pubkey = payer_pubkey();
1783                 let mut tlv_stream = invoice.as_tlv_stream();
1784                 tlv_stream.3.node_id = Some(&invalid_pubkey);
1785
1786                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
1787                         Ok(_) => panic!("expected error"),
1788                         Err(e) => {
1789                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidSigningPubkey));
1790                         },
1791                 }
1792         }
1793
1794         #[test]
1795         fn fails_parsing_invoice_without_signature() {
1796                 let mut buffer = Vec::new();
1797                 OfferBuilder::new("foo".into(), recipient_pubkey())
1798                         .amount_msats(1000)
1799                         .build().unwrap()
1800                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1801                         .build().unwrap()
1802                         .sign(payer_sign).unwrap()
1803                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1804                         .build().unwrap()
1805                         .contents
1806                         .write(&mut buffer).unwrap();
1807
1808                 match Bolt12Invoice::try_from(buffer) {
1809                         Ok(_) => panic!("expected error"),
1810                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
1811                 }
1812         }
1813
1814         #[test]
1815         fn fails_parsing_invoice_with_invalid_signature() {
1816                 let mut invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1817                         .amount_msats(1000)
1818                         .build().unwrap()
1819                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1820                         .build().unwrap()
1821                         .sign(payer_sign).unwrap()
1822                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1823                         .build().unwrap()
1824                         .sign(recipient_sign).unwrap();
1825                 let last_signature_byte = invoice.bytes.last_mut().unwrap();
1826                 *last_signature_byte = last_signature_byte.wrapping_add(1);
1827
1828                 let mut buffer = Vec::new();
1829                 invoice.write(&mut buffer).unwrap();
1830
1831                 match Bolt12Invoice::try_from(buffer) {
1832                         Ok(_) => panic!("expected error"),
1833                         Err(e) => {
1834                                 assert_eq!(e, Bolt12ParseError::InvalidSignature(secp256k1::Error::InvalidSignature));
1835                         },
1836                 }
1837         }
1838
1839         #[test]
1840         fn fails_parsing_invoice_with_extra_tlv_records() {
1841                 let invoice = OfferBuilder::new("foo".into(), recipient_pubkey())
1842                         .amount_msats(1000)
1843                         .build().unwrap()
1844                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1845                         .build().unwrap()
1846                         .sign(payer_sign).unwrap()
1847                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1848                         .build().unwrap()
1849                         .sign(recipient_sign).unwrap();
1850
1851                 let mut encoded_invoice = Vec::new();
1852                 invoice.write(&mut encoded_invoice).unwrap();
1853                 BigSize(1002).write(&mut encoded_invoice).unwrap();
1854                 BigSize(32).write(&mut encoded_invoice).unwrap();
1855                 [42u8; 32].write(&mut encoded_invoice).unwrap();
1856
1857                 match Bolt12Invoice::try_from(encoded_invoice) {
1858                         Ok(_) => panic!("expected error"),
1859                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1860                 }
1861         }
1862 }