_ 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::TryFrom;
  26 //! use lightning::offers::invoice::UnsignedBolt12Invoice;
  27 //! use lightning::offers::invoice_request::InvoiceRequest;
  28 //! use lightning::offers::refund::Refund;
  29 //! use lightning::util::ser::Writeable;
  30 //!
  31 //! # use lightning::ln::types::PaymentHash;
  32 //! # use lightning::offers::invoice::{BlindedPayInfo, ExplicitSigningPubkey, InvoiceBuilder};
  33 //! # use lightning::blinded_path::BlindedPath;
  34 //! #
  35 //! # fn create_payment_paths() -> Vec<(BlindedPayInfo, BlindedPath)> { unimplemented!() }
  36 //! # fn create_payment_hash() -> PaymentHash { unimplemented!() }
  37 //! #
  38 //! # fn parse_invoice_request(bytes: Vec<u8>) -> Result<(), lightning::offers::parse::Bolt12ParseError> {
  39 //! let payment_paths = create_payment_paths();
  40 //! let payment_hash = create_payment_hash();
  41 //! let secp_ctx = Secp256k1::new();
  42 //! let keys = Keypair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32])?);
  43 //! let pubkey = PublicKey::from(keys);
  44 //! let wpubkey_hash = bitcoin::key::PublicKey::new(pubkey).wpubkey_hash().unwrap();
  45 //! let mut buffer = Vec::new();
  46 //!
  47 //! // Invoice for the "offer to be paid" flow.
  48 //! # <InvoiceBuilder<ExplicitSigningPubkey>>::from(
  49 //! InvoiceRequest::try_from(bytes)?
  50 #![cfg_attr(feature = "std", doc = "
  51     .respond_with(payment_paths, payment_hash)?
  52 ")]
  53 #![cfg_attr(not(feature = "std"), doc = "
  54     .respond_with_no_std(payment_paths, payment_hash, core::time::Duration::from_secs(0))?
  55 ")]
  56 //! # )
  57 //!     .relative_expiry(3600)
  58 //!     .allow_mpp()
  59 //!     .fallback_v0_p2wpkh(&wpubkey_hash)
  60 //!     .build()?
  61 //!     .sign(|message: &UnsignedBolt12Invoice|
  62 //!         Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
  63 //!     )
  64 //!     .expect("failed verifying signature")
  65 //!     .write(&mut buffer)
  66 //!     .unwrap();
  67 //! # Ok(())
  68 //! # }
  69 //!
  70 //! # fn parse_refund(bytes: Vec<u8>) -> Result<(), lightning::offers::parse::Bolt12ParseError> {
  71 //! # let payment_paths = create_payment_paths();
  72 //! # let payment_hash = create_payment_hash();
  73 //! # let secp_ctx = Secp256k1::new();
  74 //! # let keys = Keypair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32])?);
  75 //! # let pubkey = PublicKey::from(keys);
  76 //! # let wpubkey_hash = bitcoin::key::PublicKey::new(pubkey).wpubkey_hash().unwrap();
  77 //! # let mut buffer = Vec::new();
  78 //!
  79 //! // Invoice for the "offer for money" flow.
  80 //! # <InvoiceBuilder<ExplicitSigningPubkey>>::from(
  81 //! "lnr1qcp4256ypq"
  82 //!     .parse::<Refund>()?
  83 #![cfg_attr(feature = "std", doc = "
  84     .respond_with(payment_paths, payment_hash, pubkey)?
  85 ")]
  86 #![cfg_attr(not(feature = "std"), doc = "
  87     .respond_with_no_std(payment_paths, payment_hash, pubkey, core::time::Duration::from_secs(0))?
  88 ")]
  89 //! # )
  90 //!     .relative_expiry(3600)
  91 //!     .allow_mpp()
  92 //!     .fallback_v0_p2wpkh(&wpubkey_hash)
  93 //!     .build()?
  94 //!     .sign(|message: &UnsignedBolt12Invoice|
  95 //!         Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
  96 //!     )
  97 //!     .expect("failed verifying signature")
  98 //!     .write(&mut buffer)
  99 //!     .unwrap();
 100 //! # Ok(())
 101 //! # }
 102 //!
 103 //! ```
 104
 105 use bitcoin::{WitnessProgram, Network, WitnessVersion};
 106 use bitcoin::blockdata::constants::ChainHash;
 107 use bitcoin::secp256k1::{Keypair, PublicKey, Secp256k1, self};
 108 use bitcoin::secp256k1::schnorr::Signature;
 109 use bitcoin::address::{Address, Payload};
 110 use core::time::Duration;
 111 use core::hash::{Hash, Hasher};
 112 use crate::io;
 113 use crate::blinded_path::BlindedPath;
 114 use crate::ln::types::PaymentHash;
 115 use crate::ln::channelmanager::PaymentId;
 116 use crate::ln::features::{BlindedHopFeatures, Bolt12InvoiceFeatures, InvoiceRequestFeatures, OfferFeatures};
 117 use crate::ln::inbound_payment::ExpandedKey;
 118 use crate::ln::msgs::DecodeError;
 119 use crate::offers::invoice_macros::{invoice_accessors_common, invoice_builder_methods_common};
 120 use crate::offers::invoice_request::{INVOICE_REQUEST_PAYER_ID_TYPE, INVOICE_REQUEST_TYPES, IV_BYTES as INVOICE_REQUEST_IV_BYTES, InvoiceRequest, InvoiceRequestContents, InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef};
 121 use crate::offers::merkle::{SignError, SignFn, SignatureTlvStream, SignatureTlvStreamRef, TaggedHash, TlvStream, WithoutSignatures, self};
 122 use crate::offers::offer::{Amount, OFFER_TYPES, OfferTlvStream, OfferTlvStreamRef, Quantity};
 123 use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError, ParsedMessage};
 124 use crate::offers::payer::{PAYER_METADATA_TYPE, PayerTlvStream, PayerTlvStreamRef};
 125 use crate::offers::refund::{IV_BYTES as REFUND_IV_BYTES, Refund, RefundContents};
 126 use crate::offers::signer;
 127 use crate::util::ser::{HighZeroBytesDroppedBigSize, Iterable, Readable, SeekReadable, WithoutLength, Writeable, Writer};
 128 use crate::util::string::PrintableString;
 129
 130 #[allow(unused_imports)]
 131 use crate::prelude::*;
 132
 133 #[cfg(feature = "std")]
 134 use std::time::SystemTime;
 135
 136 pub(crate) const DEFAULT_RELATIVE_EXPIRY: Duration = Duration::from_secs(7200);
 137
 138 /// Tag for the hash function used when signing a [`Bolt12Invoice`]'s merkle root.
 139 pub const SIGNATURE_TAG: &'static str = concat!("lightning", "invoice", "signature");
 140
 141 /// Builds a [`Bolt12Invoice`] from either:
 142 /// - an [`InvoiceRequest`] for the "offer to be paid" flow or
 143 /// - a [`Refund`] for the "offer for money" flow.
 144 ///
 145 /// See [module-level documentation] for usage.
 146 ///
 147 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 148 ///
 149 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 150 /// [`Refund`]: crate::offers::refund::Refund
 151 /// [module-level documentation]: self
 152 pub struct InvoiceBuilder<'a, S: SigningPubkeyStrategy> {
 153         invreq_bytes: &'a Vec<u8>,
 154         invoice: InvoiceContents,
 155         signing_pubkey_strategy: S,
 156 }
 157
 158 /// Builds a [`Bolt12Invoice`] from either:
 159 /// - an [`InvoiceRequest`] for the "offer to be paid" flow or
 160 /// - a [`Refund`] for the "offer for money" flow.
 161 ///
 162 /// See [module-level documentation] for usage.
 163 ///
 164 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 165 /// [`Refund`]: crate::offers::refund::Refund
 166 /// [module-level documentation]: self
 167 #[cfg(c_bindings)]
 168 pub struct InvoiceWithExplicitSigningPubkeyBuilder<'a> {
 169         invreq_bytes: &'a Vec<u8>,
 170         invoice: InvoiceContents,
 171         signing_pubkey_strategy: ExplicitSigningPubkey,
 172 }
 173
 174 /// Builds a [`Bolt12Invoice`] from either:
 175 /// - an [`InvoiceRequest`] for the "offer to be paid" flow or
 176 /// - a [`Refund`] for the "offer for money" flow.
 177 ///
 178 /// See [module-level documentation] for usage.
 179 ///
 180 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 181 /// [`Refund`]: crate::offers::refund::Refund
 182 /// [module-level documentation]: self
 183 #[cfg(c_bindings)]
 184 pub struct InvoiceWithDerivedSigningPubkeyBuilder<'a> {
 185         invreq_bytes: &'a Vec<u8>,
 186         invoice: InvoiceContents,
 187         signing_pubkey_strategy: DerivedSigningPubkey,
 188 }
 189
 190 /// Indicates how [`Bolt12Invoice::signing_pubkey`] was set.
 191 ///
 192 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 193 pub trait SigningPubkeyStrategy {}
 194
 195 /// [`Bolt12Invoice::signing_pubkey`] was explicitly set.
 196 ///
 197 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 198 pub struct ExplicitSigningPubkey {}
 199
 200 /// [`Bolt12Invoice::signing_pubkey`] was derived.
 201 ///
 202 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 203 pub struct DerivedSigningPubkey(pub(super) Keypair);
 204
 205 impl SigningPubkeyStrategy for ExplicitSigningPubkey {}
 206 impl SigningPubkeyStrategy for DerivedSigningPubkey {}
 207
 208 macro_rules! invoice_explicit_signing_pubkey_builder_methods { ($self: ident, $self_type: ty) => {
 209         #[cfg_attr(c_bindings, allow(dead_code))]
 210         pub(super) fn for_offer(
 211                 invoice_request: &'a InvoiceRequest, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>,
 212                 created_at: Duration, payment_hash: PaymentHash, signing_pubkey: PublicKey
 213         ) -> Result<Self, Bolt12SemanticError> {
 214                 let amount_msats = Self::amount_msats(invoice_request)?;
 215                 let contents = InvoiceContents::ForOffer {
 216                         invoice_request: invoice_request.contents.clone(),
 217                         fields: Self::fields(
 218                                 payment_paths, created_at, payment_hash, amount_msats, signing_pubkey
 219                         ),
 220                 };
 221
 222                 Self::new(&invoice_request.bytes, contents, ExplicitSigningPubkey {})
 223         }
 224
 225         #[cfg_attr(c_bindings, allow(dead_code))]
 226         pub(super) fn for_refund(
 227                 refund: &'a Refund, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, created_at: Duration,
 228                 payment_hash: PaymentHash, signing_pubkey: PublicKey
 229         ) -> Result<Self, Bolt12SemanticError> {
 230                 let amount_msats = refund.amount_msats();
 231                 let contents = InvoiceContents::ForRefund {
 232                         refund: refund.contents.clone(),
 233                         fields: Self::fields(
 234                                 payment_paths, created_at, payment_hash, amount_msats, signing_pubkey
 235                         ),
 236                 };
 237
 238                 Self::new(&refund.bytes, contents, ExplicitSigningPubkey {})
 239         }
 240
 241         /// Builds an unsigned [`Bolt12Invoice`] after checking for valid semantics. It can be signed by
 242         /// [`UnsignedBolt12Invoice::sign`].
 243         pub fn build($self: $self_type) -> Result<UnsignedBolt12Invoice, Bolt12SemanticError> {
 244                 #[cfg(feature = "std")] {
 245                         if $self.invoice.is_offer_or_refund_expired() {
 246                                 return Err(Bolt12SemanticError::AlreadyExpired);
 247                         }
 248                 }
 249
 250                 #[cfg(not(feature = "std"))] {
 251                         if $self.invoice.is_offer_or_refund_expired_no_std($self.invoice.created_at()) {
 252                                 return Err(Bolt12SemanticError::AlreadyExpired);
 253                         }
 254                 }
 255
 256                 let Self { invreq_bytes, invoice, .. } = $self;
 257                 #[cfg(not(c_bindings))] {
 258                         Ok(UnsignedBolt12Invoice::new(invreq_bytes, invoice))
 259                 }
 260                 #[cfg(c_bindings)] {
 261                         Ok(UnsignedBolt12Invoice::new(invreq_bytes, invoice.clone()))
 262                 }
 263         }
 264 } }
 265
 266 macro_rules! invoice_derived_signing_pubkey_builder_methods { ($self: ident, $self_type: ty) => {
 267         #[cfg_attr(c_bindings, allow(dead_code))]
 268         pub(super) fn for_offer_using_keys(
 269                 invoice_request: &'a InvoiceRequest, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>,
 270                 created_at: Duration, payment_hash: PaymentHash, keys: Keypair
 271         ) -> Result<Self, Bolt12SemanticError> {
 272                 let amount_msats = Self::amount_msats(invoice_request)?;
 273                 let signing_pubkey = keys.public_key();
 274                 let contents = InvoiceContents::ForOffer {
 275                         invoice_request: invoice_request.contents.clone(),
 276                         fields: Self::fields(
 277                                 payment_paths, created_at, payment_hash, amount_msats, signing_pubkey
 278                         ),
 279                 };
 280
 281                 Self::new(&invoice_request.bytes, contents, DerivedSigningPubkey(keys))
 282         }
 283
 284         #[cfg_attr(c_bindings, allow(dead_code))]
 285         pub(super) fn for_refund_using_keys(
 286                 refund: &'a Refund, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, created_at: Duration,
 287                 payment_hash: PaymentHash, keys: Keypair,
 288         ) -> Result<Self, Bolt12SemanticError> {
 289                 let amount_msats = refund.amount_msats();
 290                 let signing_pubkey = keys.public_key();
 291                 let contents = InvoiceContents::ForRefund {
 292                         refund: refund.contents.clone(),
 293                         fields: Self::fields(
 294                                 payment_paths, created_at, payment_hash, amount_msats, signing_pubkey
 295                         ),
 296                 };
 297
 298                 Self::new(&refund.bytes, contents, DerivedSigningPubkey(keys))
 299         }
 300
 301         /// Builds a signed [`Bolt12Invoice`] after checking for valid semantics.
 302         pub fn build_and_sign<T: secp256k1::Signing>(
 303                 $self: $self_type, secp_ctx: &Secp256k1<T>
 304         ) -> Result<Bolt12Invoice, Bolt12SemanticError> {
 305                 #[cfg(feature = "std")] {
 306                         if $self.invoice.is_offer_or_refund_expired() {
 307                                 return Err(Bolt12SemanticError::AlreadyExpired);
 308                         }
 309                 }
 310
 311                 #[cfg(not(feature = "std"))] {
 312                         if $self.invoice.is_offer_or_refund_expired_no_std($self.invoice.created_at()) {
 313                                 return Err(Bolt12SemanticError::AlreadyExpired);
 314                         }
 315                 }
 316
 317                 let Self {
 318                         invreq_bytes, invoice, signing_pubkey_strategy: DerivedSigningPubkey(keys)
 319                 } = $self;
 320                 #[cfg(not(c_bindings))]
 321                 let unsigned_invoice = UnsignedBolt12Invoice::new(invreq_bytes, invoice);
 322                 #[cfg(c_bindings)]
 323                 let mut unsigned_invoice = UnsignedBolt12Invoice::new(invreq_bytes, invoice.clone());
 324
 325                 let invoice = unsigned_invoice
 326                         .sign(|message: &UnsignedBolt12Invoice|
 327                                 Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
 328                         )
 329                         .unwrap();
 330                 Ok(invoice)
 331         }
 332 } }
 333
 334 macro_rules! invoice_builder_methods { (
 335         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr, $type_param: ty $(, $self_mut: tt)?
 336 ) => {
 337         pub(crate) fn amount_msats(
 338                 invoice_request: &InvoiceRequest
 339         ) -> Result<u64, Bolt12SemanticError> {
 340                 match invoice_request.amount_msats() {
 341                         Some(amount_msats) => Ok(amount_msats),
 342                         None => match invoice_request.contents.inner.offer.amount() {
 343                                 Some(Amount::Bitcoin { amount_msats }) => {
 344                                         amount_msats.checked_mul(invoice_request.quantity().unwrap_or(1))
 345                                                 .ok_or(Bolt12SemanticError::InvalidAmount)
 346                                 },
 347                                 Some(Amount::Currency { .. }) => Err(Bolt12SemanticError::UnsupportedCurrency),
 348                                 None => Err(Bolt12SemanticError::MissingAmount),
 349                         },
 350                 }
 351         }
 352
 353         #[cfg_attr(c_bindings, allow(dead_code))]
 354         fn fields(
 355                 payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, created_at: Duration,
 356                 payment_hash: PaymentHash, amount_msats: u64, signing_pubkey: PublicKey
 357         ) -> InvoiceFields {
 358                 InvoiceFields {
 359                         payment_paths, created_at, relative_expiry: None, payment_hash, amount_msats,
 360                         fallbacks: None, features: Bolt12InvoiceFeatures::empty(), signing_pubkey,
 361                 }
 362         }
 363
 364         #[cfg_attr(c_bindings, allow(dead_code))]
 365         fn new(
 366                 invreq_bytes: &'a Vec<u8>, contents: InvoiceContents, signing_pubkey_strategy: $type_param
 367         ) -> Result<Self, Bolt12SemanticError> {
 368                 if contents.fields().payment_paths.is_empty() {
 369                         return Err(Bolt12SemanticError::MissingPaths);
 370                 }
 371
 372                 Ok(Self { invreq_bytes, invoice: contents, signing_pubkey_strategy })
 373         }
 374 } }
 375
 376 impl<'a> InvoiceBuilder<'a, ExplicitSigningPubkey> {
 377         invoice_explicit_signing_pubkey_builder_methods!(self, Self);
 378 }
 379
 380 impl<'a> InvoiceBuilder<'a, DerivedSigningPubkey> {
 381         invoice_derived_signing_pubkey_builder_methods!(self, Self);
 382 }
 383
 384 impl<'a, S: SigningPubkeyStrategy> InvoiceBuilder<'a, S> {
 385         invoice_builder_methods!(self, Self, Self, self, S, mut);
 386         invoice_builder_methods_common!(self, Self, self.invoice.fields_mut(), Self, self, S, Bolt12Invoice, mut);
 387 }
 388
 389 #[cfg(all(c_bindings, not(test)))]
 390 impl<'a> InvoiceWithExplicitSigningPubkeyBuilder<'a> {
 391         invoice_explicit_signing_pubkey_builder_methods!(self, &mut Self);
 392         invoice_builder_methods!(self, &mut Self, (), (), ExplicitSigningPubkey);
 393         invoice_builder_methods_common!(self, &mut Self, self.invoice.fields_mut(), (), (), ExplicitSigningPubkey, Bolt12Invoice);
 394 }
 395
 396 #[cfg(all(c_bindings, test))]
 397 impl<'a> InvoiceWithExplicitSigningPubkeyBuilder<'a> {
 398         invoice_explicit_signing_pubkey_builder_methods!(self, &mut Self);
 399         invoice_builder_methods!(self, &mut Self, &mut Self, self, ExplicitSigningPubkey);
 400         invoice_builder_methods_common!(self, &mut Self, self.invoice.fields_mut(), &mut Self, self, ExplicitSigningPubkey, Bolt12Invoice);
 401 }
 402
 403 #[cfg(all(c_bindings, not(test)))]
 404 impl<'a> InvoiceWithDerivedSigningPubkeyBuilder<'a> {
 405         invoice_derived_signing_pubkey_builder_methods!(self, &mut Self);
 406         invoice_builder_methods!(self, &mut Self, (), (), DerivedSigningPubkey);
 407         invoice_builder_methods_common!(self, &mut Self, self.invoice.fields_mut(), (), (), DerivedSigningPubkey, Bolt12Invoice);
 408 }
 409
 410 #[cfg(all(c_bindings, test))]
 411 impl<'a> InvoiceWithDerivedSigningPubkeyBuilder<'a> {
 412         invoice_derived_signing_pubkey_builder_methods!(self, &mut Self);
 413         invoice_builder_methods!(self, &mut Self, &mut Self, self, DerivedSigningPubkey);
 414         invoice_builder_methods_common!(self, &mut Self, self.invoice.fields_mut(), &mut Self, self, DerivedSigningPubkey, Bolt12Invoice);
 415 }
 416
 417 #[cfg(c_bindings)]
 418 impl<'a> From<InvoiceWithExplicitSigningPubkeyBuilder<'a>>
 419 for InvoiceBuilder<'a, ExplicitSigningPubkey> {
 420         fn from(builder: InvoiceWithExplicitSigningPubkeyBuilder<'a>) -> Self {
 421                 let InvoiceWithExplicitSigningPubkeyBuilder {
 422                         invreq_bytes, invoice, signing_pubkey_strategy,
 423                 } = builder;
 424
 425                 Self {
 426                         invreq_bytes, invoice, signing_pubkey_strategy,
 427                 }
 428         }
 429 }
 430
 431 #[cfg(c_bindings)]
 432 impl<'a> From<InvoiceWithDerivedSigningPubkeyBuilder<'a>>
 433 for InvoiceBuilder<'a, DerivedSigningPubkey> {
 434         fn from(builder: InvoiceWithDerivedSigningPubkeyBuilder<'a>) -> Self {
 435                 let InvoiceWithDerivedSigningPubkeyBuilder {
 436                         invreq_bytes, invoice, signing_pubkey_strategy,
 437                 } = builder;
 438
 439                 Self {
 440                         invreq_bytes, invoice, signing_pubkey_strategy,
 441                 }
 442         }
 443 }
 444
 445 /// A semantically valid [`Bolt12Invoice`] that hasn't been signed.
 446 ///
 447 /// # Serialization
 448 ///
 449 /// This is serialized as a TLV stream, which includes TLV records from the originating message. As
 450 /// such, it may include unknown, odd TLV records.
 451 #[derive(Clone)]
 452 pub struct UnsignedBolt12Invoice {
 453         bytes: Vec<u8>,
 454         contents: InvoiceContents,
 455         tagged_hash: TaggedHash,
 456 }
 457
 458 /// A function for signing an [`UnsignedBolt12Invoice`].
 459 pub trait SignBolt12InvoiceFn {
 460         /// Signs a [`TaggedHash`] computed over the merkle root of `message`'s TLV stream.
 461         fn sign_invoice(&self, message: &UnsignedBolt12Invoice) -> Result<Signature, ()>;
 462 }
 463
 464 impl<F> SignBolt12InvoiceFn for F
 465 where
 466         F: Fn(&UnsignedBolt12Invoice) -> Result<Signature, ()>,
 467 {
 468         fn sign_invoice(&self, message: &UnsignedBolt12Invoice) -> Result<Signature, ()> {
 469                 self(message)
 470         }
 471 }
 472
 473 impl<F> SignFn<UnsignedBolt12Invoice> for F
 474 where
 475         F: SignBolt12InvoiceFn,
 476 {
 477         fn sign(&self, message: &UnsignedBolt12Invoice) -> Result<Signature, ()> {
 478                 self.sign_invoice(message)
 479         }
 480 }
 481
 482 impl UnsignedBolt12Invoice {
 483         fn new(invreq_bytes: &[u8], contents: InvoiceContents) -> Self {
 484                 // Use the invoice_request bytes instead of the invoice_request TLV stream as the latter may
 485                 // have contained unknown TLV records, which are not stored in `InvoiceRequestContents` or
 486                 // `RefundContents`.
 487                 let (_, _, _, invoice_tlv_stream) = contents.as_tlv_stream();
 488                 let invoice_request_bytes = WithoutSignatures(invreq_bytes);
 489                 let unsigned_tlv_stream = (invoice_request_bytes, invoice_tlv_stream);
 490
 491                 let mut bytes = Vec::new();
 492                 unsigned_tlv_stream.write(&mut bytes).unwrap();
 493
 494                 let tagged_hash = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &bytes);
 495
 496                 Self { bytes, contents, tagged_hash }
 497         }
 498
 499         /// Returns the [`TaggedHash`] of the invoice to sign.
 500         pub fn tagged_hash(&self) -> &TaggedHash {
 501                 &self.tagged_hash
 502         }
 503 }
 504
 505 macro_rules! unsigned_invoice_sign_method { ($self: ident, $self_type: ty $(, $self_mut: tt)?) => {
 506         /// Signs the [`TaggedHash`] of the invoice using the given function.
 507         ///
 508         /// Note: The hash computation may have included unknown, odd TLV records.
 509         pub fn sign<F: SignBolt12InvoiceFn>(
 510                 $($self_mut)* $self: $self_type, sign: F
 511         ) -> Result<Bolt12Invoice, SignError> {
 512                 let pubkey = $self.contents.fields().signing_pubkey;
 513                 let signature = merkle::sign_message(sign, &$self, pubkey)?;
 514
 515                 // Append the signature TLV record to the bytes.
 516                 let signature_tlv_stream = SignatureTlvStreamRef {
 517                         signature: Some(&signature),
 518                 };
 519                 signature_tlv_stream.write(&mut $self.bytes).unwrap();
 520
 521                 Ok(Bolt12Invoice {
 522                         #[cfg(not(c_bindings))]
 523                         bytes: $self.bytes,
 524                         #[cfg(c_bindings)]
 525                         bytes: $self.bytes.clone(),
 526                         #[cfg(not(c_bindings))]
 527                         contents: $self.contents,
 528                         #[cfg(c_bindings)]
 529                         contents: $self.contents.clone(),
 530                         signature,
 531                         #[cfg(not(c_bindings))]
 532                         tagged_hash: $self.tagged_hash,
 533                         #[cfg(c_bindings)]
 534                         tagged_hash: $self.tagged_hash.clone(),
 535                 })
 536         }
 537 } }
 538
 539 #[cfg(not(c_bindings))]
 540 impl UnsignedBolt12Invoice {
 541         unsigned_invoice_sign_method!(self, Self, mut);
 542 }
 543
 544 #[cfg(c_bindings)]
 545 impl UnsignedBolt12Invoice {
 546         unsigned_invoice_sign_method!(self, &mut Self);
 547 }
 548
 549 impl AsRef<TaggedHash> for UnsignedBolt12Invoice {
 550         fn as_ref(&self) -> &TaggedHash {
 551                 &self.tagged_hash
 552         }
 553 }
 554
 555 /// A `Bolt12Invoice` is a payment request, typically corresponding to an [`Offer`] or a [`Refund`].
 556 ///
 557 /// An invoice may be sent in response to an [`InvoiceRequest`] in the case of an offer or sent
 558 /// directly after scanning a refund. It includes all the information needed to pay a recipient.
 559 ///
 560 /// [`Offer`]: crate::offers::offer::Offer
 561 /// [`Refund`]: crate::offers::refund::Refund
 562 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
 563 #[derive(Clone, Debug)]
 564 pub struct Bolt12Invoice {
 565         bytes: Vec<u8>,
 566         contents: InvoiceContents,
 567         signature: Signature,
 568         tagged_hash: TaggedHash,
 569 }
 570
 571 /// The contents of an [`Bolt12Invoice`] for responding to either an [`Offer`] or a [`Refund`].
 572 ///
 573 /// [`Offer`]: crate::offers::offer::Offer
 574 /// [`Refund`]: crate::offers::refund::Refund
 575 #[derive(Clone, Debug)]
 576 #[cfg_attr(test, derive(PartialEq))]
 577 enum InvoiceContents {
 578         /// Contents for an [`Bolt12Invoice`] corresponding to an [`Offer`].
 579         ///
 580         /// [`Offer`]: crate::offers::offer::Offer
 581         ForOffer {
 582                 invoice_request: InvoiceRequestContents,
 583                 fields: InvoiceFields,
 584         },
 585         /// Contents for an [`Bolt12Invoice`] corresponding to a [`Refund`].
 586         ///
 587         /// [`Refund`]: crate::offers::refund::Refund
 588         ForRefund {
 589                 refund: RefundContents,
 590                 fields: InvoiceFields,
 591         },
 592 }
 593
 594 /// Invoice-specific fields for an `invoice` message.
 595 #[derive(Clone, Debug, PartialEq)]
 596 struct InvoiceFields {
 597         payment_paths: Vec<(BlindedPayInfo, BlindedPath)>,
 598         created_at: Duration,
 599         relative_expiry: Option<Duration>,
 600         payment_hash: PaymentHash,
 601         amount_msats: u64,
 602         fallbacks: Option<Vec<FallbackAddress>>,
 603         features: Bolt12InvoiceFeatures,
 604         signing_pubkey: PublicKey,
 605 }
 606
 607 macro_rules! invoice_accessors { ($self: ident, $contents: expr) => {
 608         /// The chains that may be used when paying a requested invoice.
 609         ///
 610         /// From [`Offer::chains`]; `None` if the invoice was created in response to a [`Refund`].
 611         ///
 612         /// [`Offer::chains`]: crate::offers::offer::Offer::chains
 613         pub fn offer_chains(&$self) -> Option<Vec<ChainHash>> {
 614                 $contents.offer_chains()
 615         }
 616
 617         /// The chain that must be used when paying the invoice; selected from [`offer_chains`] if the
 618         /// invoice originated from an offer.
 619         ///
 620         /// From [`InvoiceRequest::chain`] or [`Refund::chain`].
 621         ///
 622         /// [`offer_chains`]: Self::offer_chains
 623         /// [`InvoiceRequest::chain`]: crate::offers::invoice_request::InvoiceRequest::chain
 624         pub fn chain(&$self) -> ChainHash {
 625                 $contents.chain()
 626         }
 627
 628         /// Opaque bytes set by the originating [`Offer`].
 629         ///
 630         /// From [`Offer::metadata`]; `None` if the invoice was created in response to a [`Refund`] or
 631         /// if the [`Offer`] did not set it.
 632         ///
 633         /// [`Offer`]: crate::offers::offer::Offer
 634         /// [`Offer::metadata`]: crate::offers::offer::Offer::metadata
 635         pub fn metadata(&$self) -> Option<&Vec<u8>> {
 636                 $contents.metadata()
 637         }
 638
 639         /// The minimum amount required for a successful payment of a single item.
 640         ///
 641         /// From [`Offer::amount`]; `None` if the invoice was created in response to a [`Refund`] or if
 642         /// the [`Offer`] did not set it.
 643         ///
 644         /// [`Offer`]: crate::offers::offer::Offer
 645         /// [`Offer::amount`]: crate::offers::offer::Offer::amount
 646         pub fn amount(&$self) -> Option<Amount> {
 647                 $contents.amount()
 648         }
 649
 650         /// Features pertaining to the originating [`Offer`].
 651         ///
 652         /// From [`Offer::offer_features`]; `None` if the invoice was created in response to a
 653         /// [`Refund`].
 654         ///
 655         /// [`Offer`]: crate::offers::offer::Offer
 656         /// [`Offer::offer_features`]: crate::offers::offer::Offer::offer_features
 657         pub fn offer_features(&$self) -> Option<&OfferFeatures> {
 658                 $contents.offer_features()
 659         }
 660
 661         /// A complete description of the purpose of the originating offer or refund.
 662         ///
 663         /// From [`Offer::description`] or [`Refund::description`].
 664         ///
 665         /// [`Offer::description`]: crate::offers::offer::Offer::description
 666         pub fn description(&$self) -> Option<PrintableString> {
 667                 $contents.description()
 668         }
 669
 670         /// Duration since the Unix epoch when an invoice should no longer be requested.
 671         ///
 672         /// From [`Offer::absolute_expiry`] or [`Refund::absolute_expiry`].
 673         ///
 674         /// [`Offer::absolute_expiry`]: crate::offers::offer::Offer::absolute_expiry
 675         pub fn absolute_expiry(&$self) -> Option<Duration> {
 676                 $contents.absolute_expiry()
 677         }
 678
 679         /// The issuer of the offer or refund.
 680         ///
 681         /// From [`Offer::issuer`] or [`Refund::issuer`].
 682         ///
 683         /// [`Offer::issuer`]: crate::offers::offer::Offer::issuer
 684         pub fn issuer(&$self) -> Option<PrintableString> {
 685                 $contents.issuer()
 686         }
 687
 688         /// Paths to the recipient originating from publicly reachable nodes.
 689         ///
 690         /// From [`Offer::paths`] or [`Refund::paths`].
 691         ///
 692         /// [`Offer::paths`]: crate::offers::offer::Offer::paths
 693         pub fn message_paths(&$self) -> &[BlindedPath] {
 694                 $contents.message_paths()
 695         }
 696
 697         /// The quantity of items supported.
 698         ///
 699         /// From [`Offer::supported_quantity`]; `None` if the invoice was created in response to a
 700         /// [`Refund`].
 701         ///
 702         /// [`Offer::supported_quantity`]: crate::offers::offer::Offer::supported_quantity
 703         pub fn supported_quantity(&$self) -> Option<Quantity> {
 704                 $contents.supported_quantity()
 705         }
 706
 707         /// An unpredictable series of bytes from the payer.
 708         ///
 709         /// From [`InvoiceRequest::payer_metadata`] or [`Refund::payer_metadata`].
 710         pub fn payer_metadata(&$self) -> &[u8] {
 711                 $contents.payer_metadata()
 712         }
 713
 714         /// Features pertaining to requesting an invoice.
 715         ///
 716         /// From [`InvoiceRequest::invoice_request_features`] or [`Refund::features`].
 717         pub fn invoice_request_features(&$self) -> &InvoiceRequestFeatures {
 718                 &$contents.invoice_request_features()
 719         }
 720
 721         /// The quantity of items requested or refunded for.
 722         ///
 723         /// From [`InvoiceRequest::quantity`] or [`Refund::quantity`].
 724         pub fn quantity(&$self) -> Option<u64> {
 725                 $contents.quantity()
 726         }
 727
 728         /// A possibly transient pubkey used to sign the invoice request or to send an invoice for a
 729         /// refund in case there are no [`message_paths`].
 730         ///
 731         /// [`message_paths`]: Self::message_paths
 732         pub fn payer_id(&$self) -> PublicKey {
 733                 $contents.payer_id()
 734         }
 735
 736         /// A payer-provided note reflected back in the invoice.
 737         ///
 738         /// From [`InvoiceRequest::payer_note`] or [`Refund::payer_note`].
 739         pub fn payer_note(&$self) -> Option<PrintableString> {
 740                 $contents.payer_note()
 741         }
 742
 743         /// SHA256 hash of the payment preimage that will be given in return for paying the invoice.
 744         pub fn payment_hash(&$self) -> PaymentHash {
 745                 $contents.payment_hash()
 746         }
 747
 748         /// The minimum amount required for a successful payment of the invoice.
 749         pub fn amount_msats(&$self) -> u64 {
 750                 $contents.amount_msats()
 751         }
 752 } }
 753
 754 impl UnsignedBolt12Invoice {
 755         invoice_accessors_common!(self, self.contents, Bolt12Invoice);
 756         invoice_accessors!(self, self.contents);
 757 }
 758
 759 impl Bolt12Invoice {
 760         invoice_accessors_common!(self, self.contents, Bolt12Invoice);
 761         invoice_accessors!(self, self.contents);
 762
 763         /// Signature of the invoice verified using [`Bolt12Invoice::signing_pubkey`].
 764         pub fn signature(&self) -> Signature {
 765                 self.signature
 766         }
 767
 768         /// Hash that was used for signing the invoice.
 769         pub fn signable_hash(&self) -> [u8; 32] {
 770                 self.tagged_hash.as_digest().as_ref().clone()
 771         }
 772
 773         /// Verifies that the invoice was for a request or refund created using the given key. Returns
 774         /// the associated [`PaymentId`] to use when sending the payment.
 775         pub fn verify<T: secp256k1::Signing>(
 776                 &self, key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 777         ) -> Result<PaymentId, ()> {
 778                 self.contents.verify(TlvStream::new(&self.bytes), key, secp_ctx)
 779         }
 780
 781         pub(crate) fn as_tlv_stream(&self) -> FullInvoiceTlvStreamRef {
 782                 let (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream) =
 783                         self.contents.as_tlv_stream();
 784                 let signature_tlv_stream = SignatureTlvStreamRef {
 785                         signature: Some(&self.signature),
 786                 };
 787                 (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
 788                  signature_tlv_stream)
 789         }
 790 }
 791
 792 impl PartialEq for Bolt12Invoice {
 793         fn eq(&self, other: &Self) -> bool {
 794                 self.bytes.eq(&other.bytes)
 795         }
 796 }
 797
 798 impl Eq for Bolt12Invoice {}
 799
 800 impl Hash for Bolt12Invoice {
 801         fn hash<H: Hasher>(&self, state: &mut H) {
 802                 self.bytes.hash(state);
 803         }
 804 }
 805
 806 impl InvoiceContents {
 807         /// Whether the original offer or refund has expired.
 808         #[cfg(feature = "std")]
 809         fn is_offer_or_refund_expired(&self) -> bool {
 810                 match self {
 811                         InvoiceContents::ForOffer { invoice_request, .. } =>
 812                                 invoice_request.inner.offer.is_expired(),
 813                         InvoiceContents::ForRefund { refund, .. } => refund.is_expired(),
 814                 }
 815         }
 816
 817         #[cfg(not(feature = "std"))]
 818         fn is_offer_or_refund_expired_no_std(&self, duration_since_epoch: Duration) -> bool {
 819                 match self {
 820                         InvoiceContents::ForOffer { invoice_request, .. } =>
 821                                 invoice_request.inner.offer.is_expired_no_std(duration_since_epoch),
 822                         InvoiceContents::ForRefund { refund, .. } =>
 823                                 refund.is_expired_no_std(duration_since_epoch),
 824                 }
 825         }
 826
 827         fn offer_chains(&self) -> Option<Vec<ChainHash>> {
 828                 match self {
 829                         InvoiceContents::ForOffer { invoice_request, .. } =>
 830                                 Some(invoice_request.inner.offer.chains()),
 831                         InvoiceContents::ForRefund { .. } => None,
 832                 }
 833         }
 834
 835         fn chain(&self) -> ChainHash {
 836                 match self {
 837                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.chain(),
 838                         InvoiceContents::ForRefund { refund, .. } => refund.chain(),
 839                 }
 840         }
 841
 842         fn metadata(&self) -> Option<&Vec<u8>> {
 843                 match self {
 844                         InvoiceContents::ForOffer { invoice_request, .. } =>
 845                                 invoice_request.inner.offer.metadata(),
 846                         InvoiceContents::ForRefund { .. } => None,
 847                 }
 848         }
 849
 850         fn amount(&self) -> Option<Amount> {
 851                 match self {
 852                         InvoiceContents::ForOffer { invoice_request, .. } =>
 853                                 invoice_request.inner.offer.amount(),
 854                         InvoiceContents::ForRefund { .. } => None,
 855                 }
 856         }
 857
 858         fn description(&self) -> Option<PrintableString> {
 859                 match self {
 860                         InvoiceContents::ForOffer { invoice_request, .. } => {
 861                                 invoice_request.inner.offer.description()
 862                         },
 863                         InvoiceContents::ForRefund { refund, .. } => Some(refund.description()),
 864                 }
 865         }
 866
 867         fn offer_features(&self) -> Option<&OfferFeatures> {
 868                 match self {
 869                         InvoiceContents::ForOffer { invoice_request, .. } => {
 870                                 Some(invoice_request.inner.offer.features())
 871                         },
 872                         InvoiceContents::ForRefund { .. } => None,
 873                 }
 874         }
 875
 876         fn absolute_expiry(&self) -> Option<Duration> {
 877                 match self {
 878                         InvoiceContents::ForOffer { invoice_request, .. } => {
 879                                 invoice_request.inner.offer.absolute_expiry()
 880                         },
 881                         InvoiceContents::ForRefund { refund, .. } => refund.absolute_expiry(),
 882                 }
 883         }
 884
 885         fn issuer(&self) -> Option<PrintableString> {
 886                 match self {
 887                         InvoiceContents::ForOffer { invoice_request, .. } => {
 888                                 invoice_request.inner.offer.issuer()
 889                         },
 890                         InvoiceContents::ForRefund { refund, .. } => refund.issuer(),
 891                 }
 892         }
 893
 894         fn message_paths(&self) -> &[BlindedPath] {
 895                 match self {
 896                         InvoiceContents::ForOffer { invoice_request, .. } => {
 897                                 invoice_request.inner.offer.paths()
 898                         },
 899                         InvoiceContents::ForRefund { refund, .. } => refund.paths(),
 900                 }
 901         }
 902
 903         fn supported_quantity(&self) -> Option<Quantity> {
 904                 match self {
 905                         InvoiceContents::ForOffer { invoice_request, .. } => {
 906                                 Some(invoice_request.inner.offer.supported_quantity())
 907                         },
 908                         InvoiceContents::ForRefund { .. } => None,
 909                 }
 910         }
 911
 912         fn payer_metadata(&self) -> &[u8] {
 913                 match self {
 914                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.metadata(),
 915                         InvoiceContents::ForRefund { refund, .. } => refund.metadata(),
 916                 }
 917         }
 918
 919         fn invoice_request_features(&self) -> &InvoiceRequestFeatures {
 920                 match self {
 921                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.features(),
 922                         InvoiceContents::ForRefund { refund, .. } => refund.features(),
 923                 }
 924         }
 925
 926         fn quantity(&self) -> Option<u64> {
 927                 match self {
 928                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.quantity(),
 929                         InvoiceContents::ForRefund { refund, .. } => refund.quantity(),
 930                 }
 931         }
 932
 933         fn payer_id(&self) -> PublicKey {
 934                 match self {
 935                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.payer_id(),
 936                         InvoiceContents::ForRefund { refund, .. } => refund.payer_id(),
 937                 }
 938         }
 939
 940         fn payer_note(&self) -> Option<PrintableString> {
 941                 match self {
 942                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.payer_note(),
 943                         InvoiceContents::ForRefund { refund, .. } => refund.payer_note(),
 944                 }
 945         }
 946
 947         fn payment_paths(&self) -> &[(BlindedPayInfo, BlindedPath)] {
 948                 &self.fields().payment_paths[..]
 949         }
 950
 951         fn created_at(&self) -> Duration {
 952                 self.fields().created_at
 953         }
 954
 955         fn relative_expiry(&self) -> Duration {
 956                 self.fields().relative_expiry.unwrap_or(DEFAULT_RELATIVE_EXPIRY)
 957         }
 958
 959         #[cfg(feature = "std")]
 960         fn is_expired(&self) -> bool {
 961                 is_expired(self.created_at(), self.relative_expiry())
 962         }
 963
 964         fn payment_hash(&self) -> PaymentHash {
 965                 self.fields().payment_hash
 966         }
 967
 968         fn amount_msats(&self) -> u64 {
 969                 self.fields().amount_msats
 970         }
 971
 972         fn fallbacks(&self) -> Vec<Address> {
 973                 self.fields().fallbacks
 974                         .as_ref()
 975                         .map(|fallbacks| filter_fallbacks(self.chain(), fallbacks))
 976                         .unwrap_or_else(Vec::new)
 977         }
 978
 979         fn features(&self) -> &Bolt12InvoiceFeatures {
 980                 &self.fields().features
 981         }
 982
 983         fn signing_pubkey(&self) -> PublicKey {
 984                 self.fields().signing_pubkey
 985         }
 986
 987         fn fields(&self) -> &InvoiceFields {
 988                 match self {
 989                         InvoiceContents::ForOffer { fields, .. } => fields,
 990                         InvoiceContents::ForRefund { fields, .. } => fields,
 991                 }
 992         }
 993
 994         fn fields_mut(&mut self) -> &mut InvoiceFields {
 995                 match self {
 996                         InvoiceContents::ForOffer { fields, .. } => fields,
 997                         InvoiceContents::ForRefund { fields, .. } => fields,
 998                 }
 999         }
1000
1001         fn verify<T: secp256k1::Signing>(
1002                 &self, tlv_stream: TlvStream<'_>, key: &ExpandedKey, secp_ctx: &Secp256k1<T>
1003         ) -> Result<PaymentId, ()> {
1004                 let offer_records = tlv_stream.clone().range(OFFER_TYPES);
1005                 let invreq_records = tlv_stream.range(INVOICE_REQUEST_TYPES).filter(|record| {
1006                         match record.r#type {
1007                                 PAYER_METADATA_TYPE => false, // Should be outside range
1008                                 INVOICE_REQUEST_PAYER_ID_TYPE => !self.derives_keys(),
1009                                 _ => true,
1010                         }
1011                 });
1012                 let tlv_stream = offer_records.chain(invreq_records);
1013
1014                 let (metadata, payer_id, iv_bytes) = match self {
1015                         InvoiceContents::ForOffer { invoice_request, .. } => {
1016                                 (invoice_request.metadata(), invoice_request.payer_id(), INVOICE_REQUEST_IV_BYTES)
1017                         },
1018                         InvoiceContents::ForRefund { refund, .. } => {
1019                                 (refund.metadata(), refund.payer_id(), REFUND_IV_BYTES)
1020                         },
1021                 };
1022
1023                 signer::verify_payer_metadata(metadata, key, iv_bytes, payer_id, tlv_stream, secp_ctx)
1024         }
1025
1026         fn derives_keys(&self) -> bool {
1027                 match self {
1028                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.derives_keys(),
1029                         InvoiceContents::ForRefund { refund, .. } => refund.derives_keys(),
1030                 }
1031         }
1032
1033         fn as_tlv_stream(&self) -> PartialInvoiceTlvStreamRef {
1034                 let (payer, offer, invoice_request) = match self {
1035                         InvoiceContents::ForOffer { invoice_request, .. } => invoice_request.as_tlv_stream(),
1036                         InvoiceContents::ForRefund { refund, .. } => refund.as_tlv_stream(),
1037                 };
1038                 let invoice = self.fields().as_tlv_stream();
1039
1040                 (payer, offer, invoice_request, invoice)
1041         }
1042 }
1043
1044 #[cfg(feature = "std")]
1045 pub(super) fn is_expired(created_at: Duration, relative_expiry: Duration) -> bool {
1046         let absolute_expiry = created_at.checked_add(relative_expiry);
1047         match absolute_expiry {
1048                 Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() {
1049                         Ok(elapsed) => elapsed > seconds_from_epoch,
1050                         Err(_) => false,
1051                 },
1052                 None => false,
1053         }
1054 }
1055
1056 pub(super) fn filter_fallbacks(
1057         chain: ChainHash, fallbacks: &Vec<FallbackAddress>
1058 ) -> Vec<Address> {
1059         let network = if chain == ChainHash::using_genesis_block(Network::Bitcoin) {
1060                 Network::Bitcoin
1061         } else if chain == ChainHash::using_genesis_block(Network::Testnet) {
1062                 Network::Testnet
1063         } else if chain == ChainHash::using_genesis_block(Network::Signet) {
1064                 Network::Signet
1065         } else if chain == ChainHash::using_genesis_block(Network::Regtest) {
1066                 Network::Regtest
1067         } else {
1068                 return Vec::new()
1069         };
1070
1071         let to_valid_address = |address: &FallbackAddress| {
1072                 let version = match WitnessVersion::try_from(address.version) {
1073                         Ok(version) => version,
1074                         Err(_) => return None,
1075                 };
1076
1077                 let program = address.program.clone();
1078                 let witness_program = match WitnessProgram::new(version, program) {
1079                         Ok(witness_program) => witness_program,
1080                         Err(_) => return None,
1081                 };
1082                 Some(Address::new(network, Payload::WitnessProgram(witness_program)))
1083         };
1084
1085         fallbacks.iter().filter_map(to_valid_address).collect()
1086 }
1087
1088 impl InvoiceFields {
1089         fn as_tlv_stream(&self) -> InvoiceTlvStreamRef {
1090                 let features = {
1091                         if self.features == Bolt12InvoiceFeatures::empty() { None }
1092                         else { Some(&self.features) }
1093                 };
1094
1095                 InvoiceTlvStreamRef {
1096                         paths: Some(Iterable(self.payment_paths.iter().map(|(_, path)| path))),
1097                         blindedpay: Some(Iterable(self.payment_paths.iter().map(|(payinfo, _)| payinfo))),
1098                         created_at: Some(self.created_at.as_secs()),
1099                         relative_expiry: self.relative_expiry.map(|duration| duration.as_secs() as u32),
1100                         payment_hash: Some(&self.payment_hash),
1101                         amount: Some(self.amount_msats),
1102                         fallbacks: self.fallbacks.as_ref(),
1103                         features,
1104                         node_id: Some(&self.signing_pubkey),
1105                         message_paths: None,
1106                 }
1107         }
1108 }
1109
1110 impl Writeable for UnsignedBolt12Invoice {
1111         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
1112                 WithoutLength(&self.bytes).write(writer)
1113         }
1114 }
1115
1116 impl Writeable for Bolt12Invoice {
1117         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
1118                 WithoutLength(&self.bytes).write(writer)
1119         }
1120 }
1121
1122 impl Readable for Bolt12Invoice {
1123         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
1124                 let bytes: WithoutLength<Vec<u8>> = Readable::read(reader)?;
1125                 Self::try_from(bytes.0).map_err(|_| DecodeError::InvalidValue)
1126         }
1127 }
1128
1129 impl Writeable for InvoiceContents {
1130         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
1131                 self.as_tlv_stream().write(writer)
1132         }
1133 }
1134
1135 impl TryFrom<Vec<u8>> for UnsignedBolt12Invoice {
1136         type Error = Bolt12ParseError;
1137
1138         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
1139                 let invoice = ParsedMessage::<PartialInvoiceTlvStream>::try_from(bytes)?;
1140                 let ParsedMessage { bytes, tlv_stream } = invoice;
1141                 let (
1142                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
1143                 ) = tlv_stream;
1144                 let contents = InvoiceContents::try_from(
1145                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream)
1146                 )?;
1147
1148                 let tagged_hash = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &bytes);
1149
1150                 Ok(UnsignedBolt12Invoice { bytes, contents, tagged_hash })
1151         }
1152 }
1153
1154 impl TryFrom<Vec<u8>> for Bolt12Invoice {
1155         type Error = Bolt12ParseError;
1156
1157         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
1158                 let parsed_invoice = ParsedMessage::<FullInvoiceTlvStream>::try_from(bytes)?;
1159                 Bolt12Invoice::try_from(parsed_invoice)
1160         }
1161 }
1162
1163 tlv_stream!(InvoiceTlvStream, InvoiceTlvStreamRef, 160..240, {
1164         (160, paths: (Vec<BlindedPath>, WithoutLength, Iterable<'a, BlindedPathIter<'a>, BlindedPath>)),
1165         (162, blindedpay: (Vec<BlindedPayInfo>, WithoutLength, Iterable<'a, BlindedPayInfoIter<'a>, BlindedPayInfo>)),
1166         (164, created_at: (u64, HighZeroBytesDroppedBigSize)),
1167         (166, relative_expiry: (u32, HighZeroBytesDroppedBigSize)),
1168         (168, payment_hash: PaymentHash),
1169         (170, amount: (u64, HighZeroBytesDroppedBigSize)),
1170         (172, fallbacks: (Vec<FallbackAddress>, WithoutLength)),
1171         (174, features: (Bolt12InvoiceFeatures, WithoutLength)),
1172         (176, node_id: PublicKey),
1173         // Only present in `StaticInvoice`s.
1174         (238, message_paths: (Vec<BlindedPath>, WithoutLength)),
1175 });
1176
1177 pub(super) type BlindedPathIter<'a> = core::iter::Map<
1178         core::slice::Iter<'a, (BlindedPayInfo, BlindedPath)>,
1179         for<'r> fn(&'r (BlindedPayInfo, BlindedPath)) -> &'r BlindedPath,
1180 >;
1181
1182 pub(super) type BlindedPayInfoIter<'a> = core::iter::Map<
1183         core::slice::Iter<'a, (BlindedPayInfo, BlindedPath)>,
1184         for<'r> fn(&'r (BlindedPayInfo, BlindedPath)) -> &'r BlindedPayInfo,
1185 >;
1186
1187 /// Information needed to route a payment across a [`BlindedPath`].
1188 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
1189 pub struct BlindedPayInfo {
1190         /// Base fee charged (in millisatoshi) for the entire blinded path.
1191         pub fee_base_msat: u32,
1192
1193         /// Liquidity fee charged (in millionths of the amount transferred) for the entire blinded path
1194         /// (i.e., 10,000 is 1%).
1195         pub fee_proportional_millionths: u32,
1196
1197         /// Number of blocks subtracted from an incoming HTLC's `cltv_expiry` for the entire blinded
1198         /// path.
1199         pub cltv_expiry_delta: u16,
1200
1201         /// The minimum HTLC value (in millisatoshi) that is acceptable to all channel peers on the
1202         /// blinded path from the introduction node to the recipient, accounting for any fees, i.e., as
1203         /// seen by the recipient.
1204         pub htlc_minimum_msat: u64,
1205
1206         /// The maximum HTLC value (in millisatoshi) that is acceptable to all channel peers on the
1207         /// blinded path from the introduction node to the recipient, accounting for any fees, i.e., as
1208         /// seen by the recipient.
1209         pub htlc_maximum_msat: u64,
1210
1211         /// Features set in `encrypted_data_tlv` for the `encrypted_recipient_data` TLV record in an
1212         /// onion payload.
1213         pub features: BlindedHopFeatures,
1214 }
1215
1216 impl_writeable!(BlindedPayInfo, {
1217         fee_base_msat,
1218         fee_proportional_millionths,
1219         cltv_expiry_delta,
1220         htlc_minimum_msat,
1221         htlc_maximum_msat,
1222         features
1223 });
1224
1225 /// Wire representation for an on-chain fallback address.
1226 #[derive(Clone, Debug, PartialEq)]
1227 pub(super) struct FallbackAddress {
1228         pub(super) version: u8,
1229         pub(super) program: Vec<u8>,
1230 }
1231
1232 impl_writeable!(FallbackAddress, { version, program });
1233
1234 type FullInvoiceTlvStream =
1235         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, InvoiceTlvStream, SignatureTlvStream);
1236
1237 type FullInvoiceTlvStreamRef<'a> = (
1238         PayerTlvStreamRef<'a>,
1239         OfferTlvStreamRef<'a>,
1240         InvoiceRequestTlvStreamRef<'a>,
1241         InvoiceTlvStreamRef<'a>,
1242         SignatureTlvStreamRef<'a>,
1243 );
1244
1245 impl SeekReadable for FullInvoiceTlvStream {
1246         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
1247                 let payer = SeekReadable::read(r)?;
1248                 let offer = SeekReadable::read(r)?;
1249                 let invoice_request = SeekReadable::read(r)?;
1250                 let invoice = SeekReadable::read(r)?;
1251                 let signature = SeekReadable::read(r)?;
1252
1253                 Ok((payer, offer, invoice_request, invoice, signature))
1254         }
1255 }
1256
1257 type PartialInvoiceTlvStream =
1258         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, InvoiceTlvStream);
1259
1260 type PartialInvoiceTlvStreamRef<'a> = (
1261         PayerTlvStreamRef<'a>,
1262         OfferTlvStreamRef<'a>,
1263         InvoiceRequestTlvStreamRef<'a>,
1264         InvoiceTlvStreamRef<'a>,
1265 );
1266
1267 impl SeekReadable for PartialInvoiceTlvStream {
1268         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
1269                 let payer = SeekReadable::read(r)?;
1270                 let offer = SeekReadable::read(r)?;
1271                 let invoice_request = SeekReadable::read(r)?;
1272                 let invoice = SeekReadable::read(r)?;
1273
1274                 Ok((payer, offer, invoice_request, invoice))
1275         }
1276 }
1277
1278 impl TryFrom<ParsedMessage<FullInvoiceTlvStream>> for Bolt12Invoice {
1279         type Error = Bolt12ParseError;
1280
1281         fn try_from(invoice: ParsedMessage<FullInvoiceTlvStream>) -> Result<Self, Self::Error> {
1282                 let ParsedMessage { bytes, tlv_stream } = invoice;
1283                 let (
1284                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
1285                         SignatureTlvStream { signature },
1286                 ) = tlv_stream;
1287                 let contents = InvoiceContents::try_from(
1288                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream)
1289                 )?;
1290
1291                 let signature = signature.ok_or(
1292                         Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)
1293                 )?;
1294                 let tagged_hash = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &bytes);
1295                 let pubkey = contents.fields().signing_pubkey;
1296                 merkle::verify_signature(&signature, &tagged_hash, pubkey)?;
1297
1298                 Ok(Bolt12Invoice { bytes, contents, signature, tagged_hash })
1299         }
1300 }
1301
1302 impl TryFrom<PartialInvoiceTlvStream> for InvoiceContents {
1303         type Error = Bolt12SemanticError;
1304
1305         fn try_from(tlv_stream: PartialInvoiceTlvStream) -> Result<Self, Self::Error> {
1306                 let (
1307                         payer_tlv_stream,
1308                         offer_tlv_stream,
1309                         invoice_request_tlv_stream,
1310                         InvoiceTlvStream {
1311                                 paths, blindedpay, created_at, relative_expiry, payment_hash, amount, fallbacks,
1312                                 features, node_id, message_paths,
1313                         },
1314                 ) = tlv_stream;
1315
1316                 if message_paths.is_some() { return Err(Bolt12SemanticError::UnexpectedPaths) }
1317
1318                 let payment_paths = construct_payment_paths(blindedpay, paths)?;
1319
1320                 let created_at = match created_at {
1321                         None => return Err(Bolt12SemanticError::MissingCreationTime),
1322                         Some(timestamp) => Duration::from_secs(timestamp),
1323                 };
1324
1325                 let relative_expiry = relative_expiry
1326                         .map(Into::<u64>::into)
1327                         .map(Duration::from_secs);
1328
1329                 let payment_hash = payment_hash.ok_or(Bolt12SemanticError::MissingPaymentHash)?;
1330
1331                 let amount_msats = amount.ok_or(Bolt12SemanticError::MissingAmount)?;
1332
1333                 let features = features.unwrap_or_else(Bolt12InvoiceFeatures::empty);
1334
1335                 let signing_pubkey = node_id.ok_or(Bolt12SemanticError::MissingSigningPubkey)?;
1336
1337                 let fields = InvoiceFields {
1338                         payment_paths, created_at, relative_expiry, payment_hash, amount_msats, fallbacks,
1339                         features, signing_pubkey,
1340                 };
1341
1342                 check_invoice_signing_pubkey(&fields.signing_pubkey, &offer_tlv_stream)?;
1343
1344                 if offer_tlv_stream.node_id.is_none() && offer_tlv_stream.paths.is_none() {
1345                         let refund = RefundContents::try_from(
1346                                 (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
1347                         )?;
1348                         Ok(InvoiceContents::ForRefund { refund, fields })
1349                 } else {
1350                         let invoice_request = InvoiceRequestContents::try_from(
1351                                 (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
1352                         )?;
1353                         Ok(InvoiceContents::ForOffer { invoice_request, fields })
1354                 }
1355         }
1356 }
1357
1358 pub(super) fn construct_payment_paths(
1359         blinded_payinfos: Option<Vec<BlindedPayInfo>>, blinded_paths: Option<Vec<BlindedPath>>
1360 ) -> Result<Vec<(BlindedPayInfo, BlindedPath)>, Bolt12SemanticError> {
1361         match (blinded_payinfos, blinded_paths) {
1362                 (_, None) => Err(Bolt12SemanticError::MissingPaths),
1363                 (None, _) => Err(Bolt12SemanticError::InvalidPayInfo),
1364                 (_, Some(paths)) if paths.is_empty() => Err(Bolt12SemanticError::MissingPaths),
1365                 (Some(blindedpay), Some(paths)) if paths.len() != blindedpay.len() => {
1366                         Err(Bolt12SemanticError::InvalidPayInfo)
1367                 },
1368                 (Some(blindedpay), Some(paths)) => {
1369                         Ok(blindedpay.into_iter().zip(paths.into_iter()).collect::<Vec<_>>())
1370                 },
1371         }
1372 }
1373
1374 pub(super) fn check_invoice_signing_pubkey(
1375         invoice_signing_pubkey: &PublicKey, offer_tlv_stream: &OfferTlvStream
1376 ) -> Result<(), Bolt12SemanticError> {
1377         match (&offer_tlv_stream.node_id, &offer_tlv_stream.paths) {
1378                 (Some(expected_signing_pubkey), _) => {
1379                         if invoice_signing_pubkey != expected_signing_pubkey {
1380                                 return Err(Bolt12SemanticError::InvalidSigningPubkey);
1381                         }
1382                 },
1383                 (None, Some(paths)) => {
1384                         if !paths
1385                                 .iter()
1386                                 .filter_map(|path| path.blinded_hops.last())
1387                                 .any(|last_hop| invoice_signing_pubkey == &last_hop.blinded_node_id)
1388                         {
1389                                 return Err(Bolt12SemanticError::InvalidSigningPubkey);
1390                         }
1391                 },
1392                 _ => {},
1393         }
1394         Ok(())
1395 }
1396
1397 #[cfg(test)]
1398 mod tests {
1399         use super::{Bolt12Invoice, DEFAULT_RELATIVE_EXPIRY, FallbackAddress, FullInvoiceTlvStreamRef, InvoiceTlvStreamRef, SIGNATURE_TAG, UnsignedBolt12Invoice};
1400
1401         use bitcoin::{WitnessProgram, WitnessVersion};
1402         use bitcoin::blockdata::constants::ChainHash;
1403         use bitcoin::blockdata::script::ScriptBuf;
1404         use bitcoin::hashes::Hash;
1405         use bitcoin::network::Network;
1406         use bitcoin::secp256k1::{Keypair, Message, Secp256k1, SecretKey, XOnlyPublicKey, self};
1407         use bitcoin::address::{Address, Payload};
1408         use bitcoin::key::TweakedPublicKey;
1409
1410         use core::time::Duration;
1411
1412         use crate::blinded_path::{BlindedHop, BlindedPath, IntroductionNode};
1413         use crate::sign::KeyMaterial;
1414         use crate::ln::features::{Bolt12InvoiceFeatures, InvoiceRequestFeatures, OfferFeatures};
1415         use crate::ln::inbound_payment::ExpandedKey;
1416         use crate::ln::msgs::DecodeError;
1417         use crate::offers::invoice_request::InvoiceRequestTlvStreamRef;
1418         use crate::offers::merkle::{SignError, SignatureTlvStreamRef, TaggedHash, self};
1419         use crate::offers::offer::{Amount, OfferTlvStreamRef, Quantity};
1420         use crate::prelude::*;
1421         #[cfg(not(c_bindings))]
1422         use {
1423                 crate::offers::offer::OfferBuilder,
1424                 crate::offers::refund::RefundBuilder,
1425         };
1426         #[cfg(c_bindings)]
1427         use {
1428                 crate::offers::offer::OfferWithExplicitMetadataBuilder as OfferBuilder,
1429                 crate::offers::refund::RefundMaybeWithDerivedMetadataBuilder as RefundBuilder,
1430         };
1431         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
1432         use crate::offers::payer::PayerTlvStreamRef;
1433         use crate::offers::test_utils::*;
1434         use crate::util::ser::{BigSize, Iterable, Writeable};
1435         use crate::util::string::PrintableString;
1436
1437         trait ToBytes {
1438                 fn to_bytes(&self) -> Vec<u8>;
1439         }
1440
1441         impl<'a> ToBytes for FullInvoiceTlvStreamRef<'a> {
1442                 fn to_bytes(&self) -> Vec<u8> {
1443                         let mut buffer = Vec::new();
1444                         self.0.write(&mut buffer).unwrap();
1445                         self.1.write(&mut buffer).unwrap();
1446                         self.2.write(&mut buffer).unwrap();
1447                         self.3.write(&mut buffer).unwrap();
1448                         self.4.write(&mut buffer).unwrap();
1449                         buffer
1450                 }
1451         }
1452
1453         #[test]
1454         fn builds_invoice_for_offer_with_defaults() {
1455                 let payment_paths = payment_paths();
1456                 let payment_hash = payment_hash();
1457                 let now = now();
1458                 let unsigned_invoice = OfferBuilder::new(recipient_pubkey())
1459                         .amount_msats(1000)
1460                         .build().unwrap()
1461                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1462                         .build().unwrap()
1463                         .sign(payer_sign).unwrap()
1464                         .respond_with_no_std(payment_paths.clone(), payment_hash, now).unwrap()
1465                         .build().unwrap();
1466
1467                 let mut buffer = Vec::new();
1468                 unsigned_invoice.write(&mut buffer).unwrap();
1469
1470                 assert_eq!(unsigned_invoice.bytes, buffer.as_slice());
1471                 assert_eq!(unsigned_invoice.payer_metadata(), &[1; 32]);
1472                 assert_eq!(unsigned_invoice.offer_chains(), Some(vec![ChainHash::using_genesis_block(Network::Bitcoin)]));
1473                 assert_eq!(unsigned_invoice.metadata(), None);
1474                 assert_eq!(unsigned_invoice.amount(), Some(Amount::Bitcoin { amount_msats: 1000 }));
1475                 assert_eq!(unsigned_invoice.description(), Some(PrintableString("")));
1476                 assert_eq!(unsigned_invoice.offer_features(), Some(&OfferFeatures::empty()));
1477                 assert_eq!(unsigned_invoice.absolute_expiry(), None);
1478                 assert_eq!(unsigned_invoice.message_paths(), &[]);
1479                 assert_eq!(unsigned_invoice.issuer(), None);
1480                 assert_eq!(unsigned_invoice.supported_quantity(), Some(Quantity::One));
1481                 assert_eq!(unsigned_invoice.signing_pubkey(), recipient_pubkey());
1482                 assert_eq!(unsigned_invoice.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
1483                 assert_eq!(unsigned_invoice.amount_msats(), 1000);
1484                 assert_eq!(unsigned_invoice.invoice_request_features(), &InvoiceRequestFeatures::empty());
1485                 assert_eq!(unsigned_invoice.quantity(), None);
1486                 assert_eq!(unsigned_invoice.payer_id(), payer_pubkey());
1487                 assert_eq!(unsigned_invoice.payer_note(), None);
1488                 assert_eq!(unsigned_invoice.payment_paths(), payment_paths.as_slice());
1489                 assert_eq!(unsigned_invoice.created_at(), now);
1490                 assert_eq!(unsigned_invoice.relative_expiry(), DEFAULT_RELATIVE_EXPIRY);
1491                 #[cfg(feature = "std")]
1492                 assert!(!unsigned_invoice.is_expired());
1493                 assert_eq!(unsigned_invoice.payment_hash(), payment_hash);
1494                 assert!(unsigned_invoice.fallbacks().is_empty());
1495                 assert_eq!(unsigned_invoice.invoice_features(), &Bolt12InvoiceFeatures::empty());
1496
1497                 match UnsignedBolt12Invoice::try_from(buffer) {
1498                         Err(e) => panic!("error parsing unsigned invoice: {:?}", e),
1499                         Ok(parsed) => {
1500                                 assert_eq!(parsed.bytes, unsigned_invoice.bytes);
1501                                 assert_eq!(parsed.tagged_hash, unsigned_invoice.tagged_hash);
1502                         },
1503                 }
1504
1505                 #[cfg(c_bindings)]
1506                 let mut unsigned_invoice = unsigned_invoice;
1507                 let invoice = unsigned_invoice.sign(recipient_sign).unwrap();
1508
1509                 let mut buffer = Vec::new();
1510                 invoice.write(&mut buffer).unwrap();
1511
1512                 assert_eq!(invoice.bytes, buffer.as_slice());
1513                 assert_eq!(invoice.payer_metadata(), &[1; 32]);
1514                 assert_eq!(invoice.offer_chains(), Some(vec![ChainHash::using_genesis_block(Network::Bitcoin)]));
1515                 assert_eq!(invoice.metadata(), None);
1516                 assert_eq!(invoice.amount(), Some(Amount::Bitcoin { amount_msats: 1000 }));
1517                 assert_eq!(invoice.description(), Some(PrintableString("")));
1518                 assert_eq!(invoice.offer_features(), Some(&OfferFeatures::empty()));
1519                 assert_eq!(invoice.absolute_expiry(), None);
1520                 assert_eq!(invoice.message_paths(), &[]);
1521                 assert_eq!(invoice.issuer(), None);
1522                 assert_eq!(invoice.supported_quantity(), Some(Quantity::One));
1523                 assert_eq!(invoice.signing_pubkey(), recipient_pubkey());
1524                 assert_eq!(invoice.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
1525                 assert_eq!(invoice.amount_msats(), 1000);
1526                 assert_eq!(invoice.invoice_request_features(), &InvoiceRequestFeatures::empty());
1527                 assert_eq!(invoice.quantity(), None);
1528                 assert_eq!(invoice.payer_id(), payer_pubkey());
1529                 assert_eq!(invoice.payer_note(), None);
1530                 assert_eq!(invoice.payment_paths(), payment_paths.as_slice());
1531                 assert_eq!(invoice.created_at(), now);
1532                 assert_eq!(invoice.relative_expiry(), DEFAULT_RELATIVE_EXPIRY);
1533                 #[cfg(feature = "std")]
1534                 assert!(!invoice.is_expired());
1535                 assert_eq!(invoice.payment_hash(), payment_hash);
1536                 assert!(invoice.fallbacks().is_empty());
1537                 assert_eq!(invoice.invoice_features(), &Bolt12InvoiceFeatures::empty());
1538
1539                 let message = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &invoice.bytes);
1540                 assert!(merkle::verify_signature(&invoice.signature, &message, recipient_pubkey()).is_ok());
1541
1542                 let digest = Message::from_digest(invoice.signable_hash());
1543                 let pubkey = recipient_pubkey().into();
1544                 let secp_ctx = Secp256k1::verification_only();
1545                 assert!(secp_ctx.verify_schnorr(&invoice.signature, &digest, &pubkey).is_ok());
1546
1547                 assert_eq!(
1548                         invoice.as_tlv_stream(),
1549                         (
1550                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
1551                                 OfferTlvStreamRef {
1552                                         chains: None,
1553                                         metadata: None,
1554                                         currency: None,
1555                                         amount: Some(1000),
1556                                         description: Some(&String::from("")),
1557                                         features: None,
1558                                         absolute_expiry: None,
1559                                         paths: None,
1560                                         issuer: None,
1561                                         quantity_max: None,
1562                                         node_id: Some(&recipient_pubkey()),
1563                                 },
1564                                 InvoiceRequestTlvStreamRef {
1565                                         chain: None,
1566                                         amount: None,
1567                                         features: None,
1568                                         quantity: None,
1569                                         payer_id: Some(&payer_pubkey()),
1570                                         payer_note: None,
1571                                         paths: None,
1572                                 },
1573                                 InvoiceTlvStreamRef {
1574                                         paths: Some(Iterable(payment_paths.iter().map(|(_, path)| path))),
1575                                         blindedpay: Some(Iterable(payment_paths.iter().map(|(payinfo, _)| payinfo))),
1576                                         created_at: Some(now.as_secs()),
1577                                         relative_expiry: None,
1578                                         payment_hash: Some(&payment_hash),
1579                                         amount: Some(1000),
1580                                         fallbacks: None,
1581                                         features: None,
1582                                         node_id: Some(&recipient_pubkey()),
1583                                         message_paths: None,
1584                                 },
1585                                 SignatureTlvStreamRef { signature: Some(&invoice.signature()) },
1586                         ),
1587                 );
1588
1589                 if let Err(e) = Bolt12Invoice::try_from(buffer) {
1590                         panic!("error parsing invoice: {:?}", e);
1591                 }
1592         }
1593
1594         #[test]
1595         fn builds_invoice_for_refund_with_defaults() {
1596                 let payment_paths = payment_paths();
1597                 let payment_hash = payment_hash();
1598                 let now = now();
1599                 let invoice = RefundBuilder::new(vec![1; 32], payer_pubkey(), 1000).unwrap()
1600                         .build().unwrap()
1601                         .respond_with_no_std(payment_paths.clone(), payment_hash, recipient_pubkey(), now)
1602                         .unwrap()
1603                         .build().unwrap()
1604                         .sign(recipient_sign).unwrap();
1605
1606                 let mut buffer = Vec::new();
1607                 invoice.write(&mut buffer).unwrap();
1608
1609                 assert_eq!(invoice.bytes, buffer.as_slice());
1610                 assert_eq!(invoice.payer_metadata(), &[1; 32]);
1611                 assert_eq!(invoice.offer_chains(), None);
1612                 assert_eq!(invoice.metadata(), None);
1613                 assert_eq!(invoice.amount(), None);
1614                 assert_eq!(invoice.description(), Some(PrintableString("")));
1615                 assert_eq!(invoice.offer_features(), None);
1616                 assert_eq!(invoice.absolute_expiry(), None);
1617                 assert_eq!(invoice.message_paths(), &[]);
1618                 assert_eq!(invoice.issuer(), None);
1619                 assert_eq!(invoice.supported_quantity(), None);
1620                 assert_eq!(invoice.signing_pubkey(), recipient_pubkey());
1621                 assert_eq!(invoice.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
1622                 assert_eq!(invoice.amount_msats(), 1000);
1623                 assert_eq!(invoice.invoice_request_features(), &InvoiceRequestFeatures::empty());
1624                 assert_eq!(invoice.quantity(), None);
1625                 assert_eq!(invoice.payer_id(), payer_pubkey());
1626                 assert_eq!(invoice.payer_note(), None);
1627                 assert_eq!(invoice.payment_paths(), payment_paths.as_slice());
1628                 assert_eq!(invoice.created_at(), now);
1629                 assert_eq!(invoice.relative_expiry(), DEFAULT_RELATIVE_EXPIRY);
1630                 #[cfg(feature = "std")]
1631                 assert!(!invoice.is_expired());
1632                 assert_eq!(invoice.payment_hash(), payment_hash);
1633                 assert!(invoice.fallbacks().is_empty());
1634                 assert_eq!(invoice.invoice_features(), &Bolt12InvoiceFeatures::empty());
1635
1636                 let message = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &invoice.bytes);
1637                 assert!(merkle::verify_signature(&invoice.signature, &message, recipient_pubkey()).is_ok());
1638
1639                 assert_eq!(
1640                         invoice.as_tlv_stream(),
1641                         (
1642                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
1643                                 OfferTlvStreamRef {
1644                                         chains: None,
1645                                         metadata: None,
1646                                         currency: None,
1647                                         amount: None,
1648                                         description: Some(&String::from("")),
1649                                         features: None,
1650                                         absolute_expiry: None,
1651                                         paths: None,
1652                                         issuer: None,
1653                                         quantity_max: None,
1654                                         node_id: None,
1655                                 },
1656                                 InvoiceRequestTlvStreamRef {
1657                                         chain: None,
1658                                         amount: Some(1000),
1659                                         features: None,
1660                                         quantity: None,
1661                                         payer_id: Some(&payer_pubkey()),
1662                                         payer_note: None,
1663                                         paths: None,
1664                                 },
1665                                 InvoiceTlvStreamRef {
1666                                         paths: Some(Iterable(payment_paths.iter().map(|(_, path)| path))),
1667                                         blindedpay: Some(Iterable(payment_paths.iter().map(|(payinfo, _)| payinfo))),
1668                                         created_at: Some(now.as_secs()),
1669                                         relative_expiry: None,
1670                                         payment_hash: Some(&payment_hash),
1671                                         amount: Some(1000),
1672                                         fallbacks: None,
1673                                         features: None,
1674                                         node_id: Some(&recipient_pubkey()),
1675                                         message_paths: None,
1676                                 },
1677                                 SignatureTlvStreamRef { signature: Some(&invoice.signature()) },
1678                         ),
1679                 );
1680
1681                 if let Err(e) = Bolt12Invoice::try_from(buffer) {
1682                         panic!("error parsing invoice: {:?}", e);
1683                 }
1684         }
1685
1686         #[cfg(feature = "std")]
1687         #[test]
1688         fn builds_invoice_from_offer_with_expiration() {
1689                 let future_expiry = Duration::from_secs(u64::max_value());
1690                 let past_expiry = Duration::from_secs(0);
1691
1692                 if let Err(e) = OfferBuilder::new(recipient_pubkey())
1693                         .amount_msats(1000)
1694                         .absolute_expiry(future_expiry)
1695                         .build().unwrap()
1696                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1697                         .build().unwrap()
1698                         .sign(payer_sign).unwrap()
1699                         .respond_with(payment_paths(), payment_hash())
1700                         .unwrap()
1701                         .build()
1702                 {
1703                         panic!("error building invoice: {:?}", e);
1704                 }
1705
1706                 match OfferBuilder::new(recipient_pubkey())
1707                         .amount_msats(1000)
1708                         .absolute_expiry(past_expiry)
1709                         .build().unwrap()
1710                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1711                         .build_unchecked()
1712                         .sign(payer_sign).unwrap()
1713                         .respond_with(payment_paths(), payment_hash())
1714                         .unwrap()
1715                         .build()
1716                 {
1717                         Ok(_) => panic!("expected error"),
1718                         Err(e) => assert_eq!(e, Bolt12SemanticError::AlreadyExpired),
1719                 }
1720         }
1721
1722         #[cfg(feature = "std")]
1723         #[test]
1724         fn builds_invoice_from_refund_with_expiration() {
1725                 let future_expiry = Duration::from_secs(u64::max_value());
1726                 let past_expiry = Duration::from_secs(0);
1727
1728                 if let Err(e) = RefundBuilder::new(vec![1; 32], payer_pubkey(), 1000).unwrap()
1729                         .absolute_expiry(future_expiry)
1730                         .build().unwrap()
1731                         .respond_with(payment_paths(), payment_hash(), recipient_pubkey())
1732                         .unwrap()
1733                         .build()
1734                 {
1735                         panic!("error building invoice: {:?}", e);
1736                 }
1737
1738                 match RefundBuilder::new(vec![1; 32], payer_pubkey(), 1000).unwrap()
1739                         .absolute_expiry(past_expiry)
1740                         .build().unwrap()
1741                         .respond_with(payment_paths(), payment_hash(), recipient_pubkey())
1742                         .unwrap()
1743                         .build()
1744                 {
1745                         Ok(_) => panic!("expected error"),
1746                         Err(e) => assert_eq!(e, Bolt12SemanticError::AlreadyExpired),
1747                 }
1748         }
1749
1750         #[test]
1751         fn builds_invoice_from_offer_using_derived_keys() {
1752                 let node_id = recipient_pubkey();
1753                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1754                 let entropy = FixedEntropy {};
1755                 let secp_ctx = Secp256k1::new();
1756
1757                 let blinded_path = BlindedPath {
1758                         introduction_node: IntroductionNode::NodeId(pubkey(40)),
1759                         blinding_point: pubkey(41),
1760                         blinded_hops: vec![
1761                                 BlindedHop { blinded_node_id: pubkey(42), encrypted_payload: vec![0; 43] },
1762                                 BlindedHop { blinded_node_id: node_id, encrypted_payload: vec![0; 44] },
1763                         ],
1764                 };
1765
1766                 #[cfg(c_bindings)]
1767                 use crate::offers::offer::OfferWithDerivedMetadataBuilder as OfferBuilder;
1768                 let offer = OfferBuilder
1769                         ::deriving_signing_pubkey(node_id, &expanded_key, &entropy, &secp_ctx)
1770                         .amount_msats(1000)
1771                         .path(blinded_path)
1772                         .build().unwrap();
1773                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1774                         .build().unwrap()
1775                         .sign(payer_sign).unwrap();
1776
1777                 if let Err(e) = invoice_request.clone()
1778                         .verify(&expanded_key, &secp_ctx).unwrap()
1779                         .respond_using_derived_keys_no_std(payment_paths(), payment_hash(), now()).unwrap()
1780                         .build_and_sign(&secp_ctx)
1781                 {
1782                         panic!("error building invoice: {:?}", e);
1783                 }
1784
1785                 let expanded_key = ExpandedKey::new(&KeyMaterial([41; 32]));
1786                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1787
1788                 let offer = OfferBuilder
1789                         ::deriving_signing_pubkey(node_id, &expanded_key, &entropy, &secp_ctx)
1790                         .amount_msats(1000)
1791                         // Omit the path so that node_id is used for the signing pubkey instead of deriving
1792                         .build().unwrap();
1793                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1794                         .build().unwrap()
1795                         .sign(payer_sign).unwrap();
1796
1797                 match invoice_request
1798                         .verify(&expanded_key, &secp_ctx).unwrap()
1799                         .respond_using_derived_keys_no_std(payment_paths(), payment_hash(), now())
1800                 {
1801                         Ok(_) => panic!("expected error"),
1802                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidMetadata),
1803                 }
1804         }
1805
1806         #[test]
1807         fn builds_invoice_from_refund_using_derived_keys() {
1808                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1809                 let entropy = FixedEntropy {};
1810                 let secp_ctx = Secp256k1::new();
1811
1812                 let refund = RefundBuilder::new(vec![1; 32], payer_pubkey(), 1000).unwrap()
1813                         .build().unwrap();
1814
1815                 if let Err(e) = refund
1816                         .respond_using_derived_keys_no_std(
1817                                 payment_paths(), payment_hash(), now(), &expanded_key, &entropy
1818                         )
1819                         .unwrap()
1820                         .build_and_sign(&secp_ctx)
1821                 {
1822                         panic!("error building invoice: {:?}", e);
1823                 }
1824         }
1825
1826         #[test]
1827         fn builds_invoice_with_relative_expiry() {
1828                 let now = now();
1829                 let one_hour = Duration::from_secs(3600);
1830
1831                 let invoice = OfferBuilder::new(recipient_pubkey())
1832                         .amount_msats(1000)
1833                         .build().unwrap()
1834                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1835                         .build().unwrap()
1836                         .sign(payer_sign).unwrap()
1837                         .respond_with_no_std(payment_paths(), payment_hash(), now).unwrap()
1838                         .relative_expiry(one_hour.as_secs() as u32)
1839                         .build().unwrap()
1840                         .sign(recipient_sign).unwrap();
1841                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1842                 #[cfg(feature = "std")]
1843                 assert!(!invoice.is_expired());
1844                 assert_eq!(invoice.relative_expiry(), one_hour);
1845                 assert_eq!(tlv_stream.relative_expiry, Some(one_hour.as_secs() as u32));
1846
1847                 let invoice = OfferBuilder::new(recipient_pubkey())
1848                         .amount_msats(1000)
1849                         .build().unwrap()
1850                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1851                         .build().unwrap()
1852                         .sign(payer_sign).unwrap()
1853                         .respond_with_no_std(payment_paths(), payment_hash(), now - one_hour).unwrap()
1854                         .relative_expiry(one_hour.as_secs() as u32 - 1)
1855                         .build().unwrap()
1856                         .sign(recipient_sign).unwrap();
1857                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1858                 #[cfg(feature = "std")]
1859                 assert!(invoice.is_expired());
1860                 assert_eq!(invoice.relative_expiry(), one_hour - Duration::from_secs(1));
1861                 assert_eq!(tlv_stream.relative_expiry, Some(one_hour.as_secs() as u32 - 1));
1862         }
1863
1864         #[test]
1865         fn builds_invoice_with_amount_from_request() {
1866                 let invoice = OfferBuilder::new(recipient_pubkey())
1867                         .amount_msats(1000)
1868                         .build().unwrap()
1869                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1870                         .amount_msats(1001).unwrap()
1871                         .build().unwrap()
1872                         .sign(payer_sign).unwrap()
1873                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1874                         .build().unwrap()
1875                         .sign(recipient_sign).unwrap();
1876                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1877                 assert_eq!(invoice.amount_msats(), 1001);
1878                 assert_eq!(tlv_stream.amount, Some(1001));
1879         }
1880
1881         #[test]
1882         fn builds_invoice_with_quantity_from_request() {
1883                 let invoice = OfferBuilder::new(recipient_pubkey())
1884                         .amount_msats(1000)
1885                         .supported_quantity(Quantity::Unbounded)
1886                         .build().unwrap()
1887                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1888                         .quantity(2).unwrap()
1889                         .build().unwrap()
1890                         .sign(payer_sign).unwrap()
1891                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1892                         .build().unwrap()
1893                         .sign(recipient_sign).unwrap();
1894                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1895                 assert_eq!(invoice.amount_msats(), 2000);
1896                 assert_eq!(tlv_stream.amount, Some(2000));
1897
1898                 match OfferBuilder::new(recipient_pubkey())
1899                         .amount_msats(1000)
1900                         .supported_quantity(Quantity::Unbounded)
1901                         .build().unwrap()
1902                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1903                         .quantity(u64::max_value()).unwrap()
1904                         .build_unchecked()
1905                         .sign(payer_sign).unwrap()
1906                         .respond_with_no_std(payment_paths(), payment_hash(), now())
1907                 {
1908                         Ok(_) => panic!("expected error"),
1909                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1910                 }
1911         }
1912
1913         #[test]
1914         fn builds_invoice_with_fallback_address() {
1915                 let script = ScriptBuf::new();
1916                 let pubkey = bitcoin::key::PublicKey::new(recipient_pubkey());
1917                 let x_only_pubkey = XOnlyPublicKey::from_keypair(&recipient_keys()).0;
1918                 let tweaked_pubkey = TweakedPublicKey::dangerous_assume_tweaked(x_only_pubkey);
1919
1920                 let invoice = OfferBuilder::new(recipient_pubkey())
1921                         .amount_msats(1000)
1922                         .build().unwrap()
1923                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1924                         .build().unwrap()
1925                         .sign(payer_sign).unwrap()
1926                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1927                         .fallback_v0_p2wsh(&script.wscript_hash())
1928                         .fallback_v0_p2wpkh(&pubkey.wpubkey_hash().unwrap())
1929                         .fallback_v1_p2tr_tweaked(&tweaked_pubkey)
1930                         .build().unwrap()
1931                         .sign(recipient_sign).unwrap();
1932                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1933                 assert_eq!(
1934                         invoice.fallbacks(),
1935                         vec![
1936                                 Address::p2wsh(&script, Network::Bitcoin),
1937                                 Address::p2wpkh(&pubkey, Network::Bitcoin).unwrap(),
1938                                 Address::p2tr_tweaked(tweaked_pubkey, Network::Bitcoin),
1939                         ],
1940                 );
1941                 assert_eq!(
1942                         tlv_stream.fallbacks,
1943                         Some(&vec![
1944                                 FallbackAddress {
1945                                         version: WitnessVersion::V0.to_num(),
1946                                         program: Vec::from(script.wscript_hash().to_byte_array()),
1947                                 },
1948                                 FallbackAddress {
1949                                         version: WitnessVersion::V0.to_num(),
1950                                         program: Vec::from(pubkey.wpubkey_hash().unwrap().to_byte_array()),
1951                                 },
1952                                 FallbackAddress {
1953                                         version: WitnessVersion::V1.to_num(),
1954                                         program: Vec::from(&tweaked_pubkey.serialize()[..]),
1955                                 },
1956                         ])
1957                 );
1958         }
1959
1960         #[test]
1961         fn builds_invoice_with_allow_mpp() {
1962                 let mut features = Bolt12InvoiceFeatures::empty();
1963                 features.set_basic_mpp_optional();
1964
1965                 let invoice = OfferBuilder::new(recipient_pubkey())
1966                         .amount_msats(1000)
1967                         .build().unwrap()
1968                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1969                         .build().unwrap()
1970                         .sign(payer_sign).unwrap()
1971                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1972                         .allow_mpp()
1973                         .build().unwrap()
1974                         .sign(recipient_sign).unwrap();
1975                 let (_, _, _, tlv_stream, _) = invoice.as_tlv_stream();
1976                 assert_eq!(invoice.invoice_features(), &features);
1977                 assert_eq!(tlv_stream.features, Some(&features));
1978         }
1979
1980         #[test]
1981         fn fails_signing_invoice() {
1982                 match OfferBuilder::new(recipient_pubkey())
1983                         .amount_msats(1000)
1984                         .build().unwrap()
1985                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1986                         .build().unwrap()
1987                         .sign(payer_sign).unwrap()
1988                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
1989                         .build().unwrap()
1990                         .sign(fail_sign)
1991                 {
1992                         Ok(_) => panic!("expected error"),
1993                         Err(e) => assert_eq!(e, SignError::Signing),
1994                 }
1995
1996                 match OfferBuilder::new(recipient_pubkey())
1997                         .amount_msats(1000)
1998                         .build().unwrap()
1999                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2000                         .build().unwrap()
2001                         .sign(payer_sign).unwrap()
2002                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
2003                         .build().unwrap()
2004                         .sign(payer_sign)
2005                 {
2006                         Ok(_) => panic!("expected error"),
2007                         Err(e) => assert_eq!(e, SignError::Verification(secp256k1::Error::InvalidSignature)),
2008                 }
2009         }
2010
2011         #[test]
2012         fn parses_invoice_with_payment_paths() {
2013                 let invoice = OfferBuilder::new(recipient_pubkey())
2014                         .amount_msats(1000)
2015                         .build().unwrap()
2016                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2017                         .build().unwrap()
2018                         .sign(payer_sign).unwrap()
2019                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
2020                         .build().unwrap()
2021                         .sign(recipient_sign).unwrap();
2022
2023                 let mut buffer = Vec::new();
2024                 invoice.write(&mut buffer).unwrap();
2025
2026                 if let Err(e) = Bolt12Invoice::try_from(buffer) {
2027                         panic!("error parsing invoice: {:?}", e);
2028                 }
2029
2030                 let mut tlv_stream = invoice.as_tlv_stream();
2031                 tlv_stream.3.paths = None;
2032
2033                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
2034                         Ok(_) => panic!("expected error"),
2035                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPaths)),
2036                 }
2037
2038                 let mut tlv_stream = invoice.as_tlv_stream();
2039                 tlv_stream.3.blindedpay = None;
2040
2041                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
2042                         Ok(_) => panic!("expected error"),
2043                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidPayInfo)),
2044                 }
2045
2046                 let empty_payment_paths = vec![];
2047                 let mut tlv_stream = invoice.as_tlv_stream();
2048                 tlv_stream.3.paths = Some(Iterable(empty_payment_paths.iter().map(|(_, path)| path)));
2049
2050                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
2051                         Ok(_) => panic!("expected error"),
2052                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPaths)),
2053                 }
2054
2055                 let mut payment_paths = payment_paths();
2056                 payment_paths.pop();
2057                 let mut tlv_stream = invoice.as_tlv_stream();
2058                 tlv_stream.3.blindedpay = Some(Iterable(payment_paths.iter().map(|(payinfo, _)| payinfo)));
2059
2060                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
2061                         Ok(_) => panic!("expected error"),
2062                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidPayInfo)),
2063                 }
2064         }
2065
2066         #[test]
2067         fn parses_invoice_with_created_at() {
2068                 let invoice = OfferBuilder::new(recipient_pubkey())
2069                         .amount_msats(1000)
2070                         .build().unwrap()
2071                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2072                         .build().unwrap()
2073                         .sign(payer_sign).unwrap()
2074                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
2075                         .build().unwrap()
2076                         .sign(recipient_sign).unwrap();
2077
2078                 let mut buffer = Vec::new();
2079                 invoice.write(&mut buffer).unwrap();
2080
2081                 if let Err(e) = Bolt12Invoice::try_from(buffer) {
2082                         panic!("error parsing invoice: {:?}", e);
2083                 }
2084
2085                 let mut tlv_stream = invoice.as_tlv_stream();
2086                 tlv_stream.3.created_at = None;
2087
2088                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
2089                         Ok(_) => panic!("expected error"),
2090                         Err(e) => {
2091                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingCreationTime));
2092                         },
2093                 }
2094         }
2095
2096         #[test]
2097         fn parses_invoice_with_relative_expiry() {
2098                 let invoice = OfferBuilder::new(recipient_pubkey())
2099                         .amount_msats(1000)
2100                         .build().unwrap()
2101                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2102                         .build().unwrap()
2103                         .sign(payer_sign).unwrap()
2104                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
2105                         .relative_expiry(3600)
2106                         .build().unwrap()
2107                         .sign(recipient_sign).unwrap();
2108
2109                 let mut buffer = Vec::new();
2110                 invoice.write(&mut buffer).unwrap();
2111
2112                 match Bolt12Invoice::try_from(buffer) {
2113                         Ok(invoice) => assert_eq!(invoice.relative_expiry(), Duration::from_secs(3600)),
2114                         Err(e) => panic!("error parsing invoice: {:?}", e),
2115                 }
2116         }
2117
2118         #[test]
2119         fn parses_invoice_with_payment_hash() {
2120                 let invoice = OfferBuilder::new(recipient_pubkey())
2121                         .amount_msats(1000)
2122                         .build().unwrap()
2123                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2124                         .build().unwrap()
2125                         .sign(payer_sign).unwrap()
2126                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
2127                         .build().unwrap()
2128                         .sign(recipient_sign).unwrap();
2129
2130                 let mut buffer = Vec::new();
2131                 invoice.write(&mut buffer).unwrap();
2132
2133                 if let Err(e) = Bolt12Invoice::try_from(buffer) {
2134                         panic!("error parsing invoice: {:?}", e);
2135                 }
2136
2137                 let mut tlv_stream = invoice.as_tlv_stream();
2138                 tlv_stream.3.payment_hash = None;
2139
2140                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
2141                         Ok(_) => panic!("expected error"),
2142                         Err(e) => {
2143                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPaymentHash));
2144                         },
2145                 }
2146         }
2147
2148         #[test]
2149         fn parses_invoice_with_amount() {
2150                 let invoice = OfferBuilder::new(recipient_pubkey())
2151                         .amount_msats(1000)
2152                         .build().unwrap()
2153                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2154                         .build().unwrap()
2155                         .sign(payer_sign).unwrap()
2156                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
2157                         .build().unwrap()
2158                         .sign(recipient_sign).unwrap();
2159
2160                 let mut buffer = Vec::new();
2161                 invoice.write(&mut buffer).unwrap();
2162
2163                 if let Err(e) = Bolt12Invoice::try_from(buffer) {
2164                         panic!("error parsing invoice: {:?}", e);
2165                 }
2166
2167                 let mut tlv_stream = invoice.as_tlv_stream();
2168                 tlv_stream.3.amount = None;
2169
2170                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
2171                         Ok(_) => panic!("expected error"),
2172                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
2173                 }
2174         }
2175
2176         #[test]
2177         fn parses_invoice_with_allow_mpp() {
2178                 let invoice = OfferBuilder::new(recipient_pubkey())
2179                         .amount_msats(1000)
2180                         .build().unwrap()
2181                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2182                         .build().unwrap()
2183                         .sign(payer_sign).unwrap()
2184                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
2185                         .allow_mpp()
2186                         .build().unwrap()
2187                         .sign(recipient_sign).unwrap();
2188
2189                 let mut buffer = Vec::new();
2190                 invoice.write(&mut buffer).unwrap();
2191
2192                 match Bolt12Invoice::try_from(buffer) {
2193                         Ok(invoice) => {
2194                                 let mut features = Bolt12InvoiceFeatures::empty();
2195                                 features.set_basic_mpp_optional();
2196                                 assert_eq!(invoice.invoice_features(), &features);
2197                         },
2198                         Err(e) => panic!("error parsing invoice: {:?}", e),
2199                 }
2200         }
2201
2202         #[test]
2203         fn parses_invoice_with_fallback_address() {
2204                 let script = ScriptBuf::new();
2205                 let pubkey = bitcoin::key::PublicKey::new(recipient_pubkey());
2206                 let x_only_pubkey = XOnlyPublicKey::from_keypair(&recipient_keys()).0;
2207                 let tweaked_pubkey = TweakedPublicKey::dangerous_assume_tweaked(x_only_pubkey);
2208
2209                 let offer = OfferBuilder::new(recipient_pubkey())
2210                         .amount_msats(1000)
2211                         .build().unwrap();
2212                 let invoice_request = offer
2213                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2214                         .build().unwrap()
2215                         .sign(payer_sign).unwrap();
2216                 #[cfg(not(c_bindings))]
2217                 let invoice_builder = invoice_request
2218                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap();
2219                 #[cfg(c_bindings)]
2220                 let mut invoice_builder = invoice_request
2221                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap();
2222                 let invoice_builder = invoice_builder
2223                         .fallback_v0_p2wsh(&script.wscript_hash())
2224                         .fallback_v0_p2wpkh(&pubkey.wpubkey_hash().unwrap())
2225                         .fallback_v1_p2tr_tweaked(&tweaked_pubkey);
2226                 #[cfg(not(c_bindings))]
2227                 let mut invoice_builder = invoice_builder;
2228
2229                 // Only standard addresses will be included.
2230                 let fallbacks = invoice_builder.invoice.fields_mut().fallbacks.as_mut().unwrap();
2231                 // Non-standard addresses
2232                 fallbacks.push(FallbackAddress { version: 1, program: vec![0u8; 41] });
2233                 fallbacks.push(FallbackAddress { version: 2, program: vec![0u8; 1] });
2234                 fallbacks.push(FallbackAddress { version: 17, program: vec![0u8; 40] });
2235                 // Standard address
2236                 fallbacks.push(FallbackAddress { version: 1, program: vec![0u8; 33] });
2237                 fallbacks.push(FallbackAddress { version: 2, program: vec![0u8; 40] });
2238
2239                 let invoice = invoice_builder.build().unwrap().sign(recipient_sign).unwrap();
2240                 let mut buffer = Vec::new();
2241                 invoice.write(&mut buffer).unwrap();
2242
2243                 match Bolt12Invoice::try_from(buffer) {
2244                         Ok(invoice) => {
2245                                 let v1_witness_program = WitnessProgram::new(WitnessVersion::V1, vec![0u8; 33]).unwrap();
2246                                 let v2_witness_program = WitnessProgram::new(WitnessVersion::V2, vec![0u8; 40]).unwrap();
2247                                 assert_eq!(
2248                                         invoice.fallbacks(),
2249                                         vec![
2250                                                 Address::p2wsh(&script, Network::Bitcoin),
2251                                                 Address::p2wpkh(&pubkey, Network::Bitcoin).unwrap(),
2252                                                 Address::p2tr_tweaked(tweaked_pubkey, Network::Bitcoin),
2253                                                 Address::new(Network::Bitcoin, Payload::WitnessProgram(v1_witness_program)),
2254                                                 Address::new(Network::Bitcoin, Payload::WitnessProgram(v2_witness_program)),
2255                                         ],
2256                                 );
2257                         },
2258                         Err(e) => panic!("error parsing invoice: {:?}", e),
2259                 }
2260         }
2261
2262         #[test]
2263         fn parses_invoice_with_node_id() {
2264                 let invoice = OfferBuilder::new(recipient_pubkey())
2265                         .amount_msats(1000)
2266                         .build().unwrap()
2267                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2268                         .build().unwrap()
2269                         .sign(payer_sign).unwrap()
2270                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
2271                         .build().unwrap()
2272                         .sign(recipient_sign).unwrap();
2273
2274                 let mut buffer = Vec::new();
2275                 invoice.write(&mut buffer).unwrap();
2276
2277                 if let Err(e) = Bolt12Invoice::try_from(buffer) {
2278                         panic!("error parsing invoice: {:?}", e);
2279                 }
2280
2281                 let mut tlv_stream = invoice.as_tlv_stream();
2282                 tlv_stream.3.node_id = None;
2283
2284                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
2285                         Ok(_) => panic!("expected error"),
2286                         Err(e) => {
2287                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
2288                         },
2289                 }
2290
2291                 let invalid_pubkey = payer_pubkey();
2292                 let mut tlv_stream = invoice.as_tlv_stream();
2293                 tlv_stream.3.node_id = Some(&invalid_pubkey);
2294
2295                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
2296                         Ok(_) => panic!("expected error"),
2297                         Err(e) => {
2298                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidSigningPubkey));
2299                         },
2300                 }
2301         }
2302
2303         #[test]
2304         fn parses_invoice_with_node_id_from_blinded_path() {
2305                 let paths = vec![
2306                         BlindedPath {
2307                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
2308                                 blinding_point: pubkey(41),
2309                                 blinded_hops: vec![
2310                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
2311                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
2312                                 ],
2313                         },
2314                         BlindedPath {
2315                                 introduction_node: IntroductionNode::NodeId(pubkey(40)),
2316                                 blinding_point: pubkey(41),
2317                                 blinded_hops: vec![
2318                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
2319                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
2320                                 ],
2321                         },
2322                 ];
2323
2324                 let blinded_node_id_sign = |message: &UnsignedBolt12Invoice| {
2325                         let secp_ctx = Secp256k1::new();
2326                         let keys = Keypair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[46; 32]).unwrap());
2327                         Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
2328                 };
2329
2330                 let invoice = OfferBuilder::new(recipient_pubkey())
2331                         .clear_signing_pubkey()
2332                         .amount_msats(1000)
2333                         .path(paths[0].clone())
2334                         .path(paths[1].clone())
2335                         .build().unwrap()
2336                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2337                         .build().unwrap()
2338                         .sign(payer_sign).unwrap()
2339                         .respond_with_no_std_using_signing_pubkey(
2340                                 payment_paths(), payment_hash(), now(), pubkey(46)
2341                         ).unwrap()
2342                         .build().unwrap()
2343                         .sign(blinded_node_id_sign).unwrap();
2344
2345                 let mut buffer = Vec::new();
2346                 invoice.write(&mut buffer).unwrap();
2347
2348                 if let Err(e) = Bolt12Invoice::try_from(buffer) {
2349                         panic!("error parsing invoice: {:?}", e);
2350                 }
2351
2352                 let invoice = OfferBuilder::new(recipient_pubkey())
2353                         .clear_signing_pubkey()
2354                         .amount_msats(1000)
2355                         .path(paths[0].clone())
2356                         .path(paths[1].clone())
2357                         .build().unwrap()
2358                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2359                         .build().unwrap()
2360                         .sign(payer_sign).unwrap()
2361                         .respond_with_no_std_using_signing_pubkey(
2362                                 payment_paths(), payment_hash(), now(), recipient_pubkey()
2363                         ).unwrap()
2364                         .build().unwrap()
2365                         .sign(recipient_sign).unwrap();
2366
2367                 let mut buffer = Vec::new();
2368                 invoice.write(&mut buffer).unwrap();
2369
2370                 match Bolt12Invoice::try_from(buffer) {
2371                         Ok(_) => panic!("expected error"),
2372                         Err(e) => {
2373                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidSigningPubkey));
2374                         },
2375                 }
2376         }
2377
2378         #[test]
2379         fn fails_parsing_invoice_without_signature() {
2380                 let mut buffer = Vec::new();
2381                 OfferBuilder::new(recipient_pubkey())
2382                         .amount_msats(1000)
2383                         .build().unwrap()
2384                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2385                         .build().unwrap()
2386                         .sign(payer_sign).unwrap()
2387                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
2388                         .build().unwrap()
2389                         .contents
2390                         .write(&mut buffer).unwrap();
2391
2392                 match Bolt12Invoice::try_from(buffer) {
2393                         Ok(_) => panic!("expected error"),
2394                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
2395                 }
2396         }
2397
2398         #[test]
2399         fn fails_parsing_invoice_with_invalid_signature() {
2400                 let mut invoice = OfferBuilder::new(recipient_pubkey())
2401                         .amount_msats(1000)
2402                         .build().unwrap()
2403                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2404                         .build().unwrap()
2405                         .sign(payer_sign).unwrap()
2406                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
2407                         .build().unwrap()
2408                         .sign(recipient_sign).unwrap();
2409                 let last_signature_byte = invoice.bytes.last_mut().unwrap();
2410                 *last_signature_byte = last_signature_byte.wrapping_add(1);
2411
2412                 let mut buffer = Vec::new();
2413                 invoice.write(&mut buffer).unwrap();
2414
2415                 match Bolt12Invoice::try_from(buffer) {
2416                         Ok(_) => panic!("expected error"),
2417                         Err(e) => {
2418                                 assert_eq!(e, Bolt12ParseError::InvalidSignature(secp256k1::Error::InvalidSignature));
2419                         },
2420                 }
2421         }
2422
2423         #[test]
2424         fn fails_parsing_invoice_with_extra_tlv_records() {
2425                 let invoice = OfferBuilder::new(recipient_pubkey())
2426                         .amount_msats(1000)
2427                         .build().unwrap()
2428                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2429                         .build().unwrap()
2430                         .sign(payer_sign).unwrap()
2431                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
2432                         .build().unwrap()
2433                         .sign(recipient_sign).unwrap();
2434
2435                 let mut encoded_invoice = Vec::new();
2436                 invoice.write(&mut encoded_invoice).unwrap();
2437                 BigSize(1002).write(&mut encoded_invoice).unwrap();
2438                 BigSize(32).write(&mut encoded_invoice).unwrap();
2439                 [42u8; 32].write(&mut encoded_invoice).unwrap();
2440
2441                 match Bolt12Invoice::try_from(encoded_invoice) {
2442                         Ok(_) => panic!("expected error"),
2443                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
2444                 }
2445         }
2446
2447         #[test]
2448         fn fails_parsing_invoice_with_message_paths() {
2449                 let invoice = OfferBuilder::new(recipient_pubkey())
2450                         .amount_msats(1000)
2451                         .build().unwrap()
2452                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2453                         .build().unwrap()
2454                         .sign(payer_sign).unwrap()
2455                         .respond_with_no_std(payment_paths(), payment_hash(), now()).unwrap()
2456                         .build().unwrap()
2457                         .sign(recipient_sign).unwrap();
2458
2459                 let blinded_path = BlindedPath {
2460                         introduction_node: IntroductionNode::NodeId(pubkey(40)),
2461                         blinding_point: pubkey(41),
2462                         blinded_hops: vec![
2463                                 BlindedHop { blinded_node_id: pubkey(42), encrypted_payload: vec![0; 43] },
2464                                 BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 44] },
2465                         ],
2466                 };
2467
2468                 let mut tlv_stream = invoice.as_tlv_stream();
2469                 let message_paths = vec![blinded_path];
2470                 tlv_stream.3.message_paths = Some(&message_paths);
2471
2472                 match Bolt12Invoice::try_from(tlv_stream.to_bytes()) {
2473                         Ok(_) => panic!("expected error"),
2474                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnexpectedPaths)),
2475                 }
2476         }
2477 }