_ Git - rust-lightning/blob - lightning/src/offers/invoice_request.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_request` messages.
  11 //!
  12 //! An [`InvoiceRequest`] can be built from a parsed [`Offer`] as an "offer to be paid". It is
  13 //! typically constructed by a customer and sent to the merchant who had published the corresponding
  14 //! offer. The recipient of the request responds with a [`Bolt12Invoice`].
  15 //!
  16 //! For an "offer for money" (e.g., refund, ATM withdrawal), where an offer doesn't exist as a
  17 //! precursor, see [`Refund`].
  18 //!
  19 //! [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
  20 //! [`Refund`]: crate::offers::refund::Refund
  21 //!
  22 //! ```
  23 //! extern crate bitcoin;
  24 //! extern crate lightning;
  25 //!
  26 //! use bitcoin::network::constants::Network;
  27 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
  28 //! use lightning::ln::features::OfferFeatures;
  29 //! use lightning::offers::invoice_request::UnsignedInvoiceRequest;
  30 //! use lightning::offers::offer::Offer;
  31 //! use lightning::util::ser::Writeable;
  32 //!
  33 //! # fn parse() -> Result<(), lightning::offers::parse::Bolt12ParseError> {
  34 //! let secp_ctx = Secp256k1::new();
  35 //! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32])?);
  36 //! let pubkey = PublicKey::from(keys);
  37 //! let mut buffer = Vec::new();
  38 //!
  39 //! # use lightning::offers::invoice_request::{ExplicitPayerId, InvoiceRequestBuilder};
  40 //! # <InvoiceRequestBuilder<ExplicitPayerId, _>>::from(
  41 //! "lno1qcp4256ypq"
  42 //!     .parse::<Offer>()?
  43 //!     .request_invoice(vec![42; 64], pubkey)?
  44 //! # )
  45 //!     .chain(Network::Testnet)?
  46 //!     .amount_msats(1000)?
  47 //!     .quantity(5)?
  48 //!     .payer_note("foo".to_string())
  49 //!     .build()?
  50 //!     .sign(|message: &UnsignedInvoiceRequest|
  51 //!         Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
  52 //!     )
  53 //!     .expect("failed verifying signature")
  54 //!     .write(&mut buffer)
  55 //!     .unwrap();
  56 //! # Ok(())
  57 //! # }
  58 //! ```
  59
  60 use bitcoin::blockdata::constants::ChainHash;
  61 use bitcoin::network::constants::Network;
  62 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, self};
  63 use bitcoin::secp256k1::schnorr::Signature;
  64 use core::ops::Deref;
  65 use crate::sign::EntropySource;
  66 use crate::io;
  67 use crate::blinded_path::BlindedPath;
  68 use crate::ln::PaymentHash;
  69 use crate::ln::channelmanager::PaymentId;
  70 use crate::ln::features::InvoiceRequestFeatures;
  71 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
  72 use crate::ln::msgs::DecodeError;
  73 use crate::offers::invoice::BlindedPayInfo;
  74 use crate::offers::merkle::{SignError, SignFn, SignatureTlvStream, SignatureTlvStreamRef, TaggedHash, self};
  75 use crate::offers::offer::{Offer, OfferContents, OfferId, OfferTlvStream, OfferTlvStreamRef};
  76 use crate::offers::parse::{Bolt12ParseError, ParsedMessage, Bolt12SemanticError};
  77 use crate::offers::payer::{PayerContents, PayerTlvStream, PayerTlvStreamRef};
  78 use crate::offers::signer::{Metadata, MetadataMaterial};
  79 use crate::util::ser::{HighZeroBytesDroppedBigSize, Readable, SeekReadable, WithoutLength, Writeable, Writer};
  80 use crate::util::string::{PrintableString, UntrustedString};
  81
  82 #[cfg(not(c_bindings))]
  83 use {
  84         crate::offers::invoice::{DerivedSigningPubkey, ExplicitSigningPubkey, InvoiceBuilder},
  85 };
  86 #[cfg(c_bindings)]
  87 use {
  88         crate::offers::invoice::{InvoiceWithDerivedSigningPubkeyBuilder, InvoiceWithExplicitSigningPubkeyBuilder},
  89 };
  90
  91 #[allow(unused_imports)]
  92 use crate::prelude::*;
  93
  94 /// Tag for the hash function used when signing an [`InvoiceRequest`]'s merkle root.
  95 pub const SIGNATURE_TAG: &'static str = concat!("lightning", "invoice_request", "signature");
  96
  97 pub(super) const IV_BYTES: &[u8; IV_LEN] = b"LDK Invreq ~~~~~";
  98
  99 /// Builds an [`InvoiceRequest`] from an [`Offer`] for the "offer to be paid" flow.
 100 ///
 101 /// See [module-level documentation] for usage.
 102 ///
 103 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 104 ///
 105 /// [module-level documentation]: self
 106 pub struct InvoiceRequestBuilder<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> {
 107         offer: &'a Offer,
 108         invoice_request: InvoiceRequestContentsWithoutPayerId,
 109         payer_id: Option<PublicKey>,
 110         payer_id_strategy: core::marker::PhantomData<P>,
 111         secp_ctx: Option<&'b Secp256k1<T>>,
 112 }
 113
 114 /// Builds an [`InvoiceRequest`] from an [`Offer`] for the "offer to be paid" flow.
 115 ///
 116 /// See [module-level documentation] for usage.
 117 ///
 118 /// [module-level documentation]: self
 119 #[cfg(c_bindings)]
 120 pub struct InvoiceRequestWithExplicitPayerIdBuilder<'a, 'b> {
 121         offer: &'a Offer,
 122         invoice_request: InvoiceRequestContentsWithoutPayerId,
 123         payer_id: Option<PublicKey>,
 124         payer_id_strategy: core::marker::PhantomData<ExplicitPayerId>,
 125         secp_ctx: Option<&'b Secp256k1<secp256k1::All>>,
 126 }
 127
 128 /// Builds an [`InvoiceRequest`] from an [`Offer`] for the "offer to be paid" flow.
 129 ///
 130 /// See [module-level documentation] for usage.
 131 ///
 132 /// [module-level documentation]: self
 133 #[cfg(c_bindings)]
 134 pub struct InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b> {
 135         offer: &'a Offer,
 136         invoice_request: InvoiceRequestContentsWithoutPayerId,
 137         payer_id: Option<PublicKey>,
 138         payer_id_strategy: core::marker::PhantomData<DerivedPayerId>,
 139         secp_ctx: Option<&'b Secp256k1<secp256k1::All>>,
 140 }
 141
 142 /// Indicates how [`InvoiceRequest::payer_id`] will be set.
 143 ///
 144 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 145 pub trait PayerIdStrategy {}
 146
 147 /// [`InvoiceRequest::payer_id`] will be explicitly set.
 148 ///
 149 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 150 pub struct ExplicitPayerId {}
 151
 152 /// [`InvoiceRequest::payer_id`] will be derived.
 153 ///
 154 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 155 pub struct DerivedPayerId {}
 156
 157 impl PayerIdStrategy for ExplicitPayerId {}
 158 impl PayerIdStrategy for DerivedPayerId {}
 159
 160 macro_rules! invoice_request_explicit_payer_id_builder_methods { ($self: ident, $self_type: ty) => {
 161         #[cfg_attr(c_bindings, allow(dead_code))]
 162         pub(super) fn new(offer: &'a Offer, metadata: Vec<u8>, payer_id: PublicKey) -> Self {
 163                 Self {
 164                         offer,
 165                         invoice_request: Self::create_contents(offer, Metadata::Bytes(metadata)),
 166                         payer_id: Some(payer_id),
 167                         payer_id_strategy: core::marker::PhantomData,
 168                         secp_ctx: None,
 169                 }
 170         }
 171
 172         #[cfg_attr(c_bindings, allow(dead_code))]
 173         pub(super) fn deriving_metadata<ES: Deref>(
 174                 offer: &'a Offer, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 175                 payment_id: PaymentId,
 176         ) -> Self where ES::Target: EntropySource {
 177                 let nonce = Nonce::from_entropy_source(entropy_source);
 178                 let payment_id = Some(payment_id);
 179                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, payment_id);
 180                 let metadata = Metadata::Derived(derivation_material);
 181                 Self {
 182                         offer,
 183                         invoice_request: Self::create_contents(offer, metadata),
 184                         payer_id: Some(payer_id),
 185                         payer_id_strategy: core::marker::PhantomData,
 186                         secp_ctx: None,
 187                 }
 188         }
 189
 190         /// Builds an unsigned [`InvoiceRequest`] after checking for valid semantics. It can be signed
 191         /// by [`UnsignedInvoiceRequest::sign`].
 192         pub fn build($self: $self_type) -> Result<UnsignedInvoiceRequest, Bolt12SemanticError> {
 193                 let (unsigned_invoice_request, keys, _) = $self.build_with_checks()?;
 194                 debug_assert!(keys.is_none());
 195                 Ok(unsigned_invoice_request)
 196         }
 197 } }
 198
 199 macro_rules! invoice_request_derived_payer_id_builder_methods { (
 200         $self: ident, $self_type: ty, $secp_context: ty
 201 ) => {
 202         #[cfg_attr(c_bindings, allow(dead_code))]
 203         pub(super) fn deriving_payer_id<ES: Deref>(
 204                 offer: &'a Offer, expanded_key: &ExpandedKey, entropy_source: ES,
 205                 secp_ctx: &'b Secp256k1<$secp_context>, payment_id: PaymentId
 206         ) -> Self where ES::Target: EntropySource {
 207                 let nonce = Nonce::from_entropy_source(entropy_source);
 208                 let payment_id = Some(payment_id);
 209                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, payment_id);
 210                 let metadata = Metadata::DerivedSigningPubkey(derivation_material);
 211                 Self {
 212                         offer,
 213                         invoice_request: Self::create_contents(offer, metadata),
 214                         payer_id: None,
 215                         payer_id_strategy: core::marker::PhantomData,
 216                         secp_ctx: Some(secp_ctx),
 217                 }
 218         }
 219
 220         /// Builds a signed [`InvoiceRequest`] after checking for valid semantics.
 221         pub fn build_and_sign($self: $self_type) -> Result<InvoiceRequest, Bolt12SemanticError> {
 222                 let (unsigned_invoice_request, keys, secp_ctx) = $self.build_with_checks()?;
 223                 #[cfg(c_bindings)]
 224                 let mut unsigned_invoice_request = unsigned_invoice_request;
 225                 debug_assert!(keys.is_some());
 226
 227                 let secp_ctx = secp_ctx.unwrap();
 228                 let keys = keys.unwrap();
 229                 let invoice_request = unsigned_invoice_request
 230                         .sign(|message: &UnsignedInvoiceRequest|
 231                                 Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
 232                         )
 233                         .unwrap();
 234                 Ok(invoice_request)
 235         }
 236 } }
 237
 238 macro_rules! invoice_request_builder_methods { (
 239         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr, $secp_context: ty $(, $self_mut: tt)?
 240 ) => {
 241         #[cfg_attr(c_bindings, allow(dead_code))]
 242         fn create_contents(offer: &Offer, metadata: Metadata) -> InvoiceRequestContentsWithoutPayerId {
 243                 let offer = offer.contents.clone();
 244                 InvoiceRequestContentsWithoutPayerId {
 245                         payer: PayerContents(metadata), offer, chain: None, amount_msats: None,
 246                         features: InvoiceRequestFeatures::empty(), quantity: None, payer_note: None,
 247                 }
 248         }
 249
 250         /// Sets the [`InvoiceRequest::chain`] of the given [`Network`] for paying an invoice. If not
 251         /// called, [`Network::Bitcoin`] is assumed. Errors if the chain for `network` is not supported
 252         /// by the offer.
 253         ///
 254         /// Successive calls to this method will override the previous setting.
 255         pub fn chain($self: $self_type, network: Network) -> Result<$return_type, Bolt12SemanticError> {
 256                 $self.chain_hash(ChainHash::using_genesis_block(network))
 257         }
 258
 259         /// Sets the [`InvoiceRequest::chain`] for paying an invoice. If not called, the chain hash of
 260         /// [`Network::Bitcoin`] is assumed. Errors if the chain for `network` is not supported by the
 261         /// offer.
 262         ///
 263         /// Successive calls to this method will override the previous setting.
 264         pub(crate) fn chain_hash($($self_mut)* $self: $self_type, chain: ChainHash) -> Result<$return_type, Bolt12SemanticError> {
 265                 if !$self.offer.supports_chain(chain) {
 266                         return Err(Bolt12SemanticError::UnsupportedChain);
 267                 }
 268
 269                 $self.invoice_request.chain = Some(chain);
 270                 Ok($return_value)
 271         }
 272
 273         /// Sets the [`InvoiceRequest::amount_msats`] for paying an invoice. Errors if `amount_msats` is
 274         /// not at least the expected invoice amount (i.e., [`Offer::amount`] times [`quantity`]).
 275         ///
 276         /// Successive calls to this method will override the previous setting.
 277         ///
 278         /// [`quantity`]: Self::quantity
 279         pub fn amount_msats($($self_mut)* $self: $self_type, amount_msats: u64) -> Result<$return_type, Bolt12SemanticError> {
 280                 $self.invoice_request.offer.check_amount_msats_for_quantity(
 281                         Some(amount_msats), $self.invoice_request.quantity
 282                 )?;
 283                 $self.invoice_request.amount_msats = Some(amount_msats);
 284                 Ok($return_value)
 285         }
 286
 287         /// Sets [`InvoiceRequest::quantity`] of items. If not set, `1` is assumed. Errors if `quantity`
 288         /// does not conform to [`Offer::is_valid_quantity`].
 289         ///
 290         /// Successive calls to this method will override the previous setting.
 291         pub fn quantity($($self_mut)* $self: $self_type, quantity: u64) -> Result<$return_type, Bolt12SemanticError> {
 292                 $self.invoice_request.offer.check_quantity(Some(quantity))?;
 293                 $self.invoice_request.quantity = Some(quantity);
 294                 Ok($return_value)
 295         }
 296
 297         /// Sets the [`InvoiceRequest::payer_note`].
 298         ///
 299         /// Successive calls to this method will override the previous setting.
 300         pub fn payer_note($($self_mut)* $self: $self_type, payer_note: String) -> $return_type {
 301                 $self.invoice_request.payer_note = Some(payer_note);
 302                 $return_value
 303         }
 304
 305         fn build_with_checks($($self_mut)* $self: $self_type) -> Result<
 306                 (UnsignedInvoiceRequest, Option<KeyPair>, Option<&'b Secp256k1<$secp_context>>),
 307                 Bolt12SemanticError
 308         > {
 309                 #[cfg(feature = "std")] {
 310                         if $self.offer.is_expired() {
 311                                 return Err(Bolt12SemanticError::AlreadyExpired);
 312                         }
 313                 }
 314
 315                 let chain = $self.invoice_request.chain();
 316                 if !$self.offer.supports_chain(chain) {
 317                         return Err(Bolt12SemanticError::UnsupportedChain);
 318                 }
 319
 320                 if chain == $self.offer.implied_chain() {
 321                         $self.invoice_request.chain = None;
 322                 }
 323
 324                 if $self.offer.amount().is_none() && $self.invoice_request.amount_msats.is_none() {
 325                         return Err(Bolt12SemanticError::MissingAmount);
 326                 }
 327
 328                 $self.invoice_request.offer.check_quantity($self.invoice_request.quantity)?;
 329                 $self.invoice_request.offer.check_amount_msats_for_quantity(
 330                         $self.invoice_request.amount_msats, $self.invoice_request.quantity
 331                 )?;
 332
 333                 Ok($self.build_without_checks())
 334         }
 335
 336         fn build_without_checks($($self_mut)* $self: $self_type) ->
 337                 (UnsignedInvoiceRequest, Option<KeyPair>, Option<&'b Secp256k1<$secp_context>>)
 338         {
 339                 // Create the metadata for stateless verification of a Bolt12Invoice.
 340                 let mut keys = None;
 341                 let secp_ctx = $self.secp_ctx.clone();
 342                 if $self.invoice_request.payer.0.has_derivation_material() {
 343                         let mut metadata = core::mem::take(&mut $self.invoice_request.payer.0);
 344
 345                         let mut tlv_stream = $self.invoice_request.as_tlv_stream();
 346                         debug_assert!(tlv_stream.2.payer_id.is_none());
 347                         tlv_stream.0.metadata = None;
 348                         if !metadata.derives_payer_keys() {
 349                                 tlv_stream.2.payer_id = $self.payer_id.as_ref();
 350                         }
 351
 352                         let (derived_metadata, derived_keys) = metadata.derive_from(tlv_stream, $self.secp_ctx);
 353                         metadata = derived_metadata;
 354                         keys = derived_keys;
 355                         if let Some(keys) = keys {
 356                                 debug_assert!($self.payer_id.is_none());
 357                                 $self.payer_id = Some(keys.public_key());
 358                         }
 359
 360                         $self.invoice_request.payer.0 = metadata;
 361                 }
 362
 363                 debug_assert!($self.invoice_request.payer.0.as_bytes().is_some());
 364                 debug_assert!($self.payer_id.is_some());
 365                 let payer_id = $self.payer_id.unwrap();
 366
 367                 let invoice_request = InvoiceRequestContents {
 368                         #[cfg(not(c_bindings))]
 369                         inner: $self.invoice_request,
 370                         #[cfg(c_bindings)]
 371                         inner: $self.invoice_request.clone(),
 372                         payer_id,
 373                 };
 374                 let unsigned_invoice_request = UnsignedInvoiceRequest::new($self.offer, invoice_request);
 375
 376                 (unsigned_invoice_request, keys, secp_ctx)
 377         }
 378 } }
 379
 380 #[cfg(test)]
 381 macro_rules! invoice_request_builder_test_methods { (
 382         $self: ident, $self_type: ty, $return_type: ty, $return_value: expr $(, $self_mut: tt)?
 383 ) => {
 384         #[cfg_attr(c_bindings, allow(dead_code))]
 385         fn chain_unchecked($($self_mut)* $self: $self_type, network: Network) -> $return_type {
 386                 let chain = ChainHash::using_genesis_block(network);
 387                 $self.invoice_request.chain = Some(chain);
 388                 $return_value
 389         }
 390
 391         #[cfg_attr(c_bindings, allow(dead_code))]
 392         fn amount_msats_unchecked($($self_mut)* $self: $self_type, amount_msats: u64) -> $return_type {
 393                 $self.invoice_request.amount_msats = Some(amount_msats);
 394                 $return_value
 395         }
 396
 397         #[cfg_attr(c_bindings, allow(dead_code))]
 398         fn features_unchecked($($self_mut)* $self: $self_type, features: InvoiceRequestFeatures) -> $return_type {
 399                 $self.invoice_request.features = features;
 400                 $return_value
 401         }
 402
 403         #[cfg_attr(c_bindings, allow(dead_code))]
 404         fn quantity_unchecked($($self_mut)* $self: $self_type, quantity: u64) -> $return_type {
 405                 $self.invoice_request.quantity = Some(quantity);
 406                 $return_value
 407         }
 408
 409         #[cfg_attr(c_bindings, allow(dead_code))]
 410         pub(super) fn build_unchecked($self: $self_type) -> UnsignedInvoiceRequest {
 411                 $self.build_without_checks().0
 412         }
 413 } }
 414
 415 impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, ExplicitPayerId, T> {
 416         invoice_request_explicit_payer_id_builder_methods!(self, Self);
 417 }
 418
 419 impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T> {
 420         invoice_request_derived_payer_id_builder_methods!(self, Self, T);
 421 }
 422
 423 impl<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, P, T> {
 424         invoice_request_builder_methods!(self, Self, Self, self, T, mut);
 425
 426         #[cfg(test)]
 427         invoice_request_builder_test_methods!(self, Self, Self, self, mut);
 428 }
 429
 430 #[cfg(all(c_bindings, not(test)))]
 431 impl<'a, 'b> InvoiceRequestWithExplicitPayerIdBuilder<'a, 'b> {
 432         invoice_request_explicit_payer_id_builder_methods!(self, &mut Self);
 433         invoice_request_builder_methods!(self, &mut Self, (), (), secp256k1::All);
 434 }
 435
 436 #[cfg(all(c_bindings, test))]
 437 impl<'a, 'b> InvoiceRequestWithExplicitPayerIdBuilder<'a, 'b> {
 438         invoice_request_explicit_payer_id_builder_methods!(self, &mut Self);
 439         invoice_request_builder_methods!(self, &mut Self, &mut Self, self, secp256k1::All);
 440         invoice_request_builder_test_methods!(self, &mut Self, &mut Self, self);
 441 }
 442
 443 #[cfg(all(c_bindings, not(test)))]
 444 impl<'a, 'b> InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b> {
 445         invoice_request_derived_payer_id_builder_methods!(self, &mut Self, secp256k1::All);
 446         invoice_request_builder_methods!(self, &mut Self, (), (), secp256k1::All);
 447 }
 448
 449 #[cfg(all(c_bindings, test))]
 450 impl<'a, 'b> InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b> {
 451         invoice_request_derived_payer_id_builder_methods!(self, &mut Self, secp256k1::All);
 452         invoice_request_builder_methods!(self, &mut Self, &mut Self, self, secp256k1::All);
 453         invoice_request_builder_test_methods!(self, &mut Self, &mut Self, self);
 454 }
 455
 456 #[cfg(c_bindings)]
 457 impl<'a, 'b> From<InvoiceRequestWithExplicitPayerIdBuilder<'a, 'b>>
 458 for InvoiceRequestBuilder<'a, 'b, ExplicitPayerId, secp256k1::All> {
 459         fn from(builder: InvoiceRequestWithExplicitPayerIdBuilder<'a, 'b>) -> Self {
 460                 let InvoiceRequestWithExplicitPayerIdBuilder {
 461                         offer, invoice_request, payer_id, payer_id_strategy, secp_ctx,
 462                 } = builder;
 463
 464                 Self {
 465                         offer, invoice_request, payer_id, payer_id_strategy, secp_ctx,
 466                 }
 467         }
 468 }
 469
 470 #[cfg(c_bindings)]
 471 impl<'a, 'b> From<InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b>>
 472 for InvoiceRequestBuilder<'a, 'b, DerivedPayerId, secp256k1::All> {
 473         fn from(builder: InvoiceRequestWithDerivedPayerIdBuilder<'a, 'b>) -> Self {
 474                 let InvoiceRequestWithDerivedPayerIdBuilder {
 475                         offer, invoice_request, payer_id, payer_id_strategy, secp_ctx,
 476                 } = builder;
 477
 478                 Self {
 479                         offer, invoice_request, payer_id, payer_id_strategy, secp_ctx,
 480                 }
 481         }
 482 }
 483
 484 /// A semantically valid [`InvoiceRequest`] that hasn't been signed.
 485 ///
 486 /// # Serialization
 487 ///
 488 /// This is serialized as a TLV stream, which includes TLV records from the originating message. As
 489 /// such, it may include unknown, odd TLV records.
 490 pub struct UnsignedInvoiceRequest {
 491         bytes: Vec<u8>,
 492         contents: InvoiceRequestContents,
 493         tagged_hash: TaggedHash,
 494 }
 495
 496 /// A function for signing an [`UnsignedInvoiceRequest`].
 497 pub trait SignInvoiceRequestFn {
 498         /// Signs a [`TaggedHash`] computed over the merkle root of `message`'s TLV stream.
 499         fn sign_invoice_request(&self, message: &UnsignedInvoiceRequest) -> Result<Signature, ()>;
 500 }
 501
 502 impl<F> SignInvoiceRequestFn for F
 503 where
 504         F: Fn(&UnsignedInvoiceRequest) -> Result<Signature, ()>,
 505 {
 506         fn sign_invoice_request(&self, message: &UnsignedInvoiceRequest) -> Result<Signature, ()> {
 507                 self(message)
 508         }
 509 }
 510
 511 impl<F> SignFn<UnsignedInvoiceRequest> for F
 512 where
 513         F: SignInvoiceRequestFn,
 514 {
 515         fn sign(&self, message: &UnsignedInvoiceRequest) -> Result<Signature, ()> {
 516                 self.sign_invoice_request(message)
 517         }
 518 }
 519
 520 impl UnsignedInvoiceRequest {
 521         fn new(offer: &Offer, contents: InvoiceRequestContents) -> Self {
 522                 // Use the offer bytes instead of the offer TLV stream as the offer may have contained
 523                 // unknown TLV records, which are not stored in `OfferContents`.
 524                 let (payer_tlv_stream, _offer_tlv_stream, invoice_request_tlv_stream) =
 525                         contents.as_tlv_stream();
 526                 let offer_bytes = WithoutLength(&offer.bytes);
 527                 let unsigned_tlv_stream = (payer_tlv_stream, offer_bytes, invoice_request_tlv_stream);
 528
 529                 let mut bytes = Vec::new();
 530                 unsigned_tlv_stream.write(&mut bytes).unwrap();
 531
 532                 let tagged_hash = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &bytes);
 533
 534                 Self { bytes, contents, tagged_hash }
 535         }
 536
 537         /// Returns the [`TaggedHash`] of the invoice to sign.
 538         pub fn tagged_hash(&self) -> &TaggedHash {
 539                 &self.tagged_hash
 540         }
 541 }
 542
 543 macro_rules! unsigned_invoice_request_sign_method { (
 544         $self: ident, $self_type: ty $(, $self_mut: tt)?
 545 ) => {
 546         /// Signs the [`TaggedHash`] of the invoice request using the given function.
 547         ///
 548         /// Note: The hash computation may have included unknown, odd TLV records.
 549         pub fn sign<F: SignInvoiceRequestFn>(
 550                 $($self_mut)* $self: $self_type, sign: F
 551         ) -> Result<InvoiceRequest, SignError> {
 552                 let pubkey = $self.contents.payer_id;
 553                 let signature = merkle::sign_message(sign, &$self, pubkey)?;
 554
 555                 // Append the signature TLV record to the bytes.
 556                 let signature_tlv_stream = SignatureTlvStreamRef {
 557                         signature: Some(&signature),
 558                 };
 559                 signature_tlv_stream.write(&mut $self.bytes).unwrap();
 560
 561                 Ok(InvoiceRequest {
 562                         #[cfg(not(c_bindings))]
 563                         bytes: $self.bytes,
 564                         #[cfg(c_bindings)]
 565                         bytes: $self.bytes.clone(),
 566                         #[cfg(not(c_bindings))]
 567                         contents: $self.contents,
 568                         #[cfg(c_bindings)]
 569                         contents: $self.contents.clone(),
 570                         signature,
 571                 })
 572         }
 573 } }
 574
 575 #[cfg(not(c_bindings))]
 576 impl UnsignedInvoiceRequest {
 577         unsigned_invoice_request_sign_method!(self, Self, mut);
 578 }
 579
 580 #[cfg(c_bindings)]
 581 impl UnsignedInvoiceRequest {
 582         unsigned_invoice_request_sign_method!(self, &mut Self);
 583 }
 584
 585 impl AsRef<TaggedHash> for UnsignedInvoiceRequest {
 586         fn as_ref(&self) -> &TaggedHash {
 587                 &self.tagged_hash
 588         }
 589 }
 590
 591 /// An `InvoiceRequest` is a request for a [`Bolt12Invoice`] formulated from an [`Offer`].
 592 ///
 593 /// An offer may provide choices such as quantity, amount, chain, features, etc. An invoice request
 594 /// specifies these such that its recipient can send an invoice for payment.
 595 ///
 596 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 597 /// [`Offer`]: crate::offers::offer::Offer
 598 #[derive(Clone, Debug)]
 599 #[cfg_attr(test, derive(PartialEq))]
 600 pub struct InvoiceRequest {
 601         pub(super) bytes: Vec<u8>,
 602         pub(super) contents: InvoiceRequestContents,
 603         signature: Signature,
 604 }
 605
 606 /// An [`InvoiceRequest`] that has been verified by [`InvoiceRequest::verify`] and exposes different
 607 /// ways to respond depending on whether the signing keys were derived.
 608 #[derive(Clone, Debug)]
 609 pub struct VerifiedInvoiceRequest {
 610         /// The identifier of the [`Offer`] for which the [`InvoiceRequest`] was made.
 611         pub offer_id: OfferId,
 612
 613         /// The verified request.
 614         inner: InvoiceRequest,
 615
 616         /// Keys used for signing a [`Bolt12Invoice`] if they can be derived.
 617         ///
 618         /// If `Some`, must call [`respond_using_derived_keys`] when responding. Otherwise, call
 619         /// [`respond_with`].
 620         ///
 621         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 622         /// [`respond_using_derived_keys`]: Self::respond_using_derived_keys
 623         /// [`respond_with`]: Self::respond_with
 624         pub keys: Option<KeyPair>,
 625 }
 626
 627 /// The contents of an [`InvoiceRequest`], which may be shared with an [`Bolt12Invoice`].
 628 ///
 629 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 630 #[derive(Clone, Debug)]
 631 #[cfg_attr(test, derive(PartialEq))]
 632 pub(super) struct InvoiceRequestContents {
 633         pub(super) inner: InvoiceRequestContentsWithoutPayerId,
 634         payer_id: PublicKey,
 635 }
 636
 637 #[derive(Clone, Debug)]
 638 #[cfg_attr(test, derive(PartialEq))]
 639 pub(super) struct InvoiceRequestContentsWithoutPayerId {
 640         payer: PayerContents,
 641         pub(super) offer: OfferContents,
 642         chain: Option<ChainHash>,
 643         amount_msats: Option<u64>,
 644         features: InvoiceRequestFeatures,
 645         quantity: Option<u64>,
 646         payer_note: Option<String>,
 647 }
 648
 649 macro_rules! invoice_request_accessors { ($self: ident, $contents: expr) => {
 650         /// An unpredictable series of bytes, typically containing information about the derivation of
 651         /// [`payer_id`].
 652         ///
 653         /// [`payer_id`]: Self::payer_id
 654         pub fn payer_metadata(&$self) -> &[u8] {
 655                 $contents.metadata()
 656         }
 657
 658         /// A chain from [`Offer::chains`] that the offer is valid for.
 659         pub fn chain(&$self) -> ChainHash {
 660                 $contents.chain()
 661         }
 662
 663         /// The amount to pay in msats (i.e., the minimum lightning-payable unit for [`chain`]), which
 664         /// must be greater than or equal to [`Offer::amount`], converted if necessary.
 665         ///
 666         /// [`chain`]: Self::chain
 667         pub fn amount_msats(&$self) -> Option<u64> {
 668                 $contents.amount_msats()
 669         }
 670
 671         /// Features pertaining to requesting an invoice.
 672         pub fn invoice_request_features(&$self) -> &InvoiceRequestFeatures {
 673                 &$contents.features()
 674         }
 675
 676         /// The quantity of the offer's item conforming to [`Offer::is_valid_quantity`].
 677         pub fn quantity(&$self) -> Option<u64> {
 678                 $contents.quantity()
 679         }
 680
 681         /// A possibly transient pubkey used to sign the invoice request.
 682         pub fn payer_id(&$self) -> PublicKey {
 683                 $contents.payer_id()
 684         }
 685
 686         /// A payer-provided note which will be seen by the recipient and reflected back in the invoice
 687         /// response.
 688         pub fn payer_note(&$self) -> Option<PrintableString> {
 689                 $contents.payer_note()
 690         }
 691 } }
 692
 693 impl UnsignedInvoiceRequest {
 694         offer_accessors!(self, self.contents.inner.offer);
 695         invoice_request_accessors!(self, self.contents);
 696 }
 697
 698 macro_rules! invoice_request_respond_with_explicit_signing_pubkey_methods { (
 699         $self: ident, $contents: expr, $builder: ty
 700 ) => {
 701         /// Creates an [`InvoiceBuilder`] for the request with the given required fields and using the
 702         /// [`Duration`] since [`std::time::SystemTime::UNIX_EPOCH`] as the creation time.
 703         ///
 704         /// See [`InvoiceRequest::respond_with_no_std`] for further details where the aforementioned
 705         /// creation time is used for the `created_at` parameter.
 706         ///
 707         /// [`Duration`]: core::time::Duration
 708         #[cfg(feature = "std")]
 709         pub fn respond_with(
 710                 &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash
 711         ) -> Result<$builder, Bolt12SemanticError> {
 712                 let created_at = std::time::SystemTime::now()
 713                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 714                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 715
 716                 $contents.respond_with_no_std(payment_paths, payment_hash, created_at)
 717         }
 718
 719         /// Creates an [`InvoiceBuilder`] for the request with the given required fields.
 720         ///
 721         /// Unless [`InvoiceBuilder::relative_expiry`] is set, the invoice will expire two hours after
 722         /// `created_at`, which is used to set [`Bolt12Invoice::created_at`]. Useful for `no-std` builds
 723         /// where [`std::time::SystemTime`] is not available.
 724         ///
 725         /// The caller is expected to remember the preimage of `payment_hash` in order to claim a payment
 726         /// for the invoice.
 727         ///
 728         /// The `payment_paths` parameter is useful for maintaining the payment recipient's privacy. It
 729         /// must contain one or more elements ordered from most-preferred to least-preferred, if there's
 730         /// a preference. Note, however, that any privacy is lost if a public node id was used for
 731         /// [`Offer::signing_pubkey`].
 732         ///
 733         /// Errors if the request contains unknown required features.
 734         ///
 735         /// # Note
 736         ///
 737         /// If the originating [`Offer`] was created using [`OfferBuilder::deriving_signing_pubkey`],
 738         /// then use [`InvoiceRequest::verify`] and [`VerifiedInvoiceRequest`] methods instead.
 739         ///
 740         /// [`Bolt12Invoice::created_at`]: crate::offers::invoice::Bolt12Invoice::created_at
 741         /// [`OfferBuilder::deriving_signing_pubkey`]: crate::offers::offer::OfferBuilder::deriving_signing_pubkey
 742         pub fn respond_with_no_std(
 743                 &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 744                 created_at: core::time::Duration
 745         ) -> Result<$builder, Bolt12SemanticError> {
 746                 if $contents.invoice_request_features().requires_unknown_bits() {
 747                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 748                 }
 749
 750                 let signing_pubkey = match $contents.contents.inner.offer.signing_pubkey() {
 751                         Some(signing_pubkey) => signing_pubkey,
 752                         None => return Err(Bolt12SemanticError::MissingSigningPubkey),
 753                 };
 754
 755                 <$builder>::for_offer(&$contents, payment_paths, created_at, payment_hash, signing_pubkey)
 756         }
 757 } }
 758
 759 macro_rules! invoice_request_verify_method { ($self: ident, $self_type: ty) => {
 760         /// Verifies that the request was for an offer created using the given key. Returns the verified
 761         /// request which contains the derived keys needed to sign a [`Bolt12Invoice`] for the request
 762         /// if they could be extracted from the metadata.
 763         ///
 764         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 765         pub fn verify<
 766                 #[cfg(not(c_bindings))]
 767                 T: secp256k1::Signing
 768         >(
 769                 $self: $self_type, key: &ExpandedKey,
 770                 #[cfg(not(c_bindings))]
 771                 secp_ctx: &Secp256k1<T>,
 772                 #[cfg(c_bindings)]
 773                 secp_ctx: &Secp256k1<secp256k1::All>,
 774         ) -> Result<VerifiedInvoiceRequest, ()> {
 775                 let (offer_id, keys) = $self.contents.inner.offer.verify(&$self.bytes, key, secp_ctx)?;
 776                 Ok(VerifiedInvoiceRequest {
 777                         offer_id,
 778                         #[cfg(not(c_bindings))]
 779                         inner: $self,
 780                         #[cfg(c_bindings)]
 781                         inner: $self.clone(),
 782                         keys,
 783                 })
 784         }
 785
 786 } }
 787
 788 #[cfg(not(c_bindings))]
 789 impl InvoiceRequest {
 790         offer_accessors!(self, self.contents.inner.offer);
 791         invoice_request_accessors!(self, self.contents);
 792         invoice_request_respond_with_explicit_signing_pubkey_methods!(self, self, InvoiceBuilder<ExplicitSigningPubkey>);
 793         invoice_request_verify_method!(self, Self);
 794 }
 795
 796 #[cfg(c_bindings)]
 797 impl InvoiceRequest {
 798         offer_accessors!(self, self.contents.inner.offer);
 799         invoice_request_accessors!(self, self.contents);
 800         invoice_request_respond_with_explicit_signing_pubkey_methods!(self, self, InvoiceWithExplicitSigningPubkeyBuilder);
 801         invoice_request_verify_method!(self, &Self);
 802 }
 803
 804 impl InvoiceRequest {
 805         /// Signature of the invoice request using [`payer_id`].
 806         ///
 807         /// [`payer_id`]: Self::payer_id
 808         pub fn signature(&self) -> Signature {
 809                 self.signature
 810         }
 811
 812         pub(crate) fn as_tlv_stream(&self) -> FullInvoiceRequestTlvStreamRef {
 813                 let (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream) =
 814                         self.contents.as_tlv_stream();
 815                 let signature_tlv_stream = SignatureTlvStreamRef {
 816                         signature: Some(&self.signature),
 817                 };
 818                 (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, signature_tlv_stream)
 819         }
 820 }
 821
 822 macro_rules! invoice_request_respond_with_derived_signing_pubkey_methods { (
 823         $self: ident, $contents: expr, $builder: ty
 824 ) => {
 825         /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
 826         /// derived signing keys from the originating [`Offer`] to sign the [`Bolt12Invoice`]. Must use
 827         /// the same [`ExpandedKey`] as the one used to create the offer.
 828         ///
 829         /// See [`InvoiceRequest::respond_with`] for further details.
 830         ///
 831         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 832         #[cfg(feature = "std")]
 833         pub fn respond_using_derived_keys(
 834                 &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash
 835         ) -> Result<$builder, Bolt12SemanticError> {
 836                 let created_at = std::time::SystemTime::now()
 837                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 838                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 839
 840                 $self.respond_using_derived_keys_no_std(payment_paths, payment_hash, created_at)
 841         }
 842
 843         /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
 844         /// derived signing keys from the originating [`Offer`] to sign the [`Bolt12Invoice`]. Must use
 845         /// the same [`ExpandedKey`] as the one used to create the offer.
 846         ///
 847         /// See [`InvoiceRequest::respond_with_no_std`] for further details.
 848         ///
 849         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 850         pub fn respond_using_derived_keys_no_std(
 851                 &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 852                 created_at: core::time::Duration
 853         ) -> Result<$builder, Bolt12SemanticError> {
 854                 if $self.inner.invoice_request_features().requires_unknown_bits() {
 855                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 856                 }
 857
 858                 let keys = match $self.keys {
 859                         None => return Err(Bolt12SemanticError::InvalidMetadata),
 860                         Some(keys) => keys,
 861                 };
 862
 863                 match $contents.contents.inner.offer.signing_pubkey() {
 864                         Some(signing_pubkey) => debug_assert_eq!(signing_pubkey, keys.public_key()),
 865                         None => return Err(Bolt12SemanticError::MissingSigningPubkey),
 866                 }
 867
 868                 <$builder>::for_offer_using_keys(
 869                         &$self.inner, payment_paths, created_at, payment_hash, keys
 870                 )
 871         }
 872 } }
 873
 874 impl VerifiedInvoiceRequest {
 875         offer_accessors!(self, self.inner.contents.inner.offer);
 876         invoice_request_accessors!(self, self.inner.contents);
 877         #[cfg(not(c_bindings))]
 878         invoice_request_respond_with_explicit_signing_pubkey_methods!(self, self.inner, InvoiceBuilder<ExplicitSigningPubkey>);
 879         #[cfg(c_bindings)]
 880         invoice_request_respond_with_explicit_signing_pubkey_methods!(self, self.inner, InvoiceWithExplicitSigningPubkeyBuilder);
 881         #[cfg(not(c_bindings))]
 882         invoice_request_respond_with_derived_signing_pubkey_methods!(self, self.inner, InvoiceBuilder<DerivedSigningPubkey>);
 883         #[cfg(c_bindings)]
 884         invoice_request_respond_with_derived_signing_pubkey_methods!(self, self.inner, InvoiceWithDerivedSigningPubkeyBuilder);
 885
 886         pub(crate) fn fields(&self) -> InvoiceRequestFields {
 887                 let InvoiceRequestContents {
 888                         payer_id,
 889                         inner: InvoiceRequestContentsWithoutPayerId {
 890                                 payer: _, offer: _, chain: _, amount_msats, features, quantity, payer_note
 891                         },
 892                 } = &self.inner.contents;
 893
 894                 InvoiceRequestFields {
 895                         payer_id: *payer_id,
 896                         amount_msats: *amount_msats,
 897                         features: features.clone(),
 898                         quantity: *quantity,
 899                         payer_note_truncated: payer_note.clone()
 900                                 .map(|mut s| { s.truncate(PAYER_NOTE_LIMIT); UntrustedString(s) }),
 901                 }
 902         }
 903 }
 904
 905 impl InvoiceRequestContents {
 906         pub(super) fn metadata(&self) -> &[u8] {
 907                 self.inner.metadata()
 908         }
 909
 910         pub(super) fn derives_keys(&self) -> bool {
 911                 self.inner.payer.0.derives_payer_keys()
 912         }
 913
 914         pub(super) fn chain(&self) -> ChainHash {
 915                 self.inner.chain()
 916         }
 917
 918         pub(super) fn amount_msats(&self) -> Option<u64> {
 919                 self.inner.amount_msats
 920         }
 921
 922         pub(super) fn features(&self) -> &InvoiceRequestFeatures {
 923                 &self.inner.features
 924         }
 925
 926         pub(super) fn quantity(&self) -> Option<u64> {
 927                 self.inner.quantity
 928         }
 929
 930         pub(super) fn payer_id(&self) -> PublicKey {
 931                 self.payer_id
 932         }
 933
 934         pub(super) fn payer_note(&self) -> Option<PrintableString> {
 935                 self.inner.payer_note.as_ref()
 936                         .map(|payer_note| PrintableString(payer_note.as_str()))
 937         }
 938
 939         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 940                 let (payer, offer, mut invoice_request) = self.inner.as_tlv_stream();
 941                 invoice_request.payer_id = Some(&self.payer_id);
 942                 (payer, offer, invoice_request)
 943         }
 944 }
 945
 946 impl InvoiceRequestContentsWithoutPayerId {
 947         pub(super) fn metadata(&self) -> &[u8] {
 948                 self.payer.0.as_bytes().map(|bytes| bytes.as_slice()).unwrap_or(&[])
 949         }
 950
 951         pub(super) fn chain(&self) -> ChainHash {
 952                 self.chain.unwrap_or_else(|| self.offer.implied_chain())
 953         }
 954
 955         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 956                 let payer = PayerTlvStreamRef {
 957                         metadata: self.payer.0.as_bytes(),
 958                 };
 959
 960                 let offer = self.offer.as_tlv_stream();
 961
 962                 let features = {
 963                         if self.features == InvoiceRequestFeatures::empty() { None }
 964                         else { Some(&self.features) }
 965                 };
 966
 967                 let invoice_request = InvoiceRequestTlvStreamRef {
 968                         chain: self.chain.as_ref(),
 969                         amount: self.amount_msats,
 970                         features,
 971                         quantity: self.quantity,
 972                         payer_id: None,
 973                         payer_note: self.payer_note.as_ref(),
 974                 };
 975
 976                 (payer, offer, invoice_request)
 977         }
 978 }
 979
 980 impl Writeable for UnsignedInvoiceRequest {
 981         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 982                 WithoutLength(&self.bytes).write(writer)
 983         }
 984 }
 985
 986 impl Writeable for InvoiceRequest {
 987         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 988                 WithoutLength(&self.bytes).write(writer)
 989         }
 990 }
 991
 992 impl Writeable for InvoiceRequestContents {
 993         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 994                 self.as_tlv_stream().write(writer)
 995         }
 996 }
 997
 998 /// Valid type range for invoice_request TLV records.
 999 pub(super) const INVOICE_REQUEST_TYPES: core::ops::Range<u64> = 80..160;
1000
1001 /// TLV record type for [`InvoiceRequest::payer_id`] and [`Refund::payer_id`].
1002 ///
1003 /// [`Refund::payer_id`]: crate::offers::refund::Refund::payer_id
1004 pub(super) const INVOICE_REQUEST_PAYER_ID_TYPE: u64 = 88;
1005
1006 tlv_stream!(InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef, INVOICE_REQUEST_TYPES, {
1007         (80, chain: ChainHash),
1008         (82, amount: (u64, HighZeroBytesDroppedBigSize)),
1009         (84, features: (InvoiceRequestFeatures, WithoutLength)),
1010         (86, quantity: (u64, HighZeroBytesDroppedBigSize)),
1011         (INVOICE_REQUEST_PAYER_ID_TYPE, payer_id: PublicKey),
1012         (89, payer_note: (String, WithoutLength)),
1013 });
1014
1015 type FullInvoiceRequestTlvStream =
1016         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, SignatureTlvStream);
1017
1018 type FullInvoiceRequestTlvStreamRef<'a> = (
1019         PayerTlvStreamRef<'a>,
1020         OfferTlvStreamRef<'a>,
1021         InvoiceRequestTlvStreamRef<'a>,
1022         SignatureTlvStreamRef<'a>,
1023 );
1024
1025 impl SeekReadable for FullInvoiceRequestTlvStream {
1026         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
1027                 let payer = SeekReadable::read(r)?;
1028                 let offer = SeekReadable::read(r)?;
1029                 let invoice_request = SeekReadable::read(r)?;
1030                 let signature = SeekReadable::read(r)?;
1031
1032                 Ok((payer, offer, invoice_request, signature))
1033         }
1034 }
1035
1036 type PartialInvoiceRequestTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
1037
1038 type PartialInvoiceRequestTlvStreamRef<'a> = (
1039         PayerTlvStreamRef<'a>,
1040         OfferTlvStreamRef<'a>,
1041         InvoiceRequestTlvStreamRef<'a>,
1042 );
1043
1044 impl TryFrom<Vec<u8>> for UnsignedInvoiceRequest {
1045         type Error = Bolt12ParseError;
1046
1047         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
1048                 let invoice_request = ParsedMessage::<PartialInvoiceRequestTlvStream>::try_from(bytes)?;
1049                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
1050                 let (
1051                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
1052                 ) = tlv_stream;
1053                 let contents = InvoiceRequestContents::try_from(
1054                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
1055                 )?;
1056
1057                 let tagged_hash = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &bytes);
1058
1059                 Ok(UnsignedInvoiceRequest { bytes, contents, tagged_hash })
1060         }
1061 }
1062
1063 impl TryFrom<Vec<u8>> for InvoiceRequest {
1064         type Error = Bolt12ParseError;
1065
1066         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
1067                 let invoice_request = ParsedMessage::<FullInvoiceRequestTlvStream>::try_from(bytes)?;
1068                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
1069                 let (
1070                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
1071                         SignatureTlvStream { signature },
1072                 ) = tlv_stream;
1073                 let contents = InvoiceRequestContents::try_from(
1074                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
1075                 )?;
1076
1077                 let signature = match signature {
1078                         None => return Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
1079                         Some(signature) => signature,
1080                 };
1081                 let message = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &bytes);
1082                 merkle::verify_signature(&signature, &message, contents.payer_id)?;
1083
1084                 Ok(InvoiceRequest { bytes, contents, signature })
1085         }
1086 }
1087
1088 impl TryFrom<PartialInvoiceRequestTlvStream> for InvoiceRequestContents {
1089         type Error = Bolt12SemanticError;
1090
1091         fn try_from(tlv_stream: PartialInvoiceRequestTlvStream) -> Result<Self, Self::Error> {
1092                 let (
1093                         PayerTlvStream { metadata },
1094                         offer_tlv_stream,
1095                         InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
1096                 ) = tlv_stream;
1097
1098                 let payer = match metadata {
1099                         None => return Err(Bolt12SemanticError::MissingPayerMetadata),
1100                         Some(metadata) => PayerContents(Metadata::Bytes(metadata)),
1101                 };
1102                 let offer = OfferContents::try_from(offer_tlv_stream)?;
1103
1104                 if !offer.supports_chain(chain.unwrap_or_else(|| offer.implied_chain())) {
1105                         return Err(Bolt12SemanticError::UnsupportedChain);
1106                 }
1107
1108                 if offer.amount().is_none() && amount.is_none() {
1109                         return Err(Bolt12SemanticError::MissingAmount);
1110                 }
1111
1112                 offer.check_quantity(quantity)?;
1113                 offer.check_amount_msats_for_quantity(amount, quantity)?;
1114
1115                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
1116
1117                 let payer_id = match payer_id {
1118                         None => return Err(Bolt12SemanticError::MissingPayerId),
1119                         Some(payer_id) => payer_id,
1120                 };
1121
1122                 Ok(InvoiceRequestContents {
1123                         inner: InvoiceRequestContentsWithoutPayerId {
1124                                 payer, offer, chain, amount_msats: amount, features, quantity, payer_note,
1125                         },
1126                         payer_id,
1127                 })
1128         }
1129 }
1130
1131 /// Fields sent in an [`InvoiceRequest`] message to include in [`PaymentContext::Bolt12Offer`].
1132 ///
1133 /// [`PaymentContext::Bolt12Offer`]: crate::blinded_path::payment::PaymentContext::Bolt12Offer
1134 #[derive(Clone, Debug, Eq, PartialEq)]
1135 pub struct InvoiceRequestFields {
1136         /// A possibly transient pubkey used to sign the invoice request.
1137         pub payer_id: PublicKey,
1138
1139         /// The amount to pay in msats (i.e., the minimum lightning-payable unit for [`chain`]), which
1140         /// must be greater than or equal to [`Offer::amount`], converted if necessary.
1141         ///
1142         /// [`chain`]: InvoiceRequest::chain
1143         pub amount_msats: Option<u64>,
1144
1145         /// Features pertaining to requesting an invoice.
1146         pub features: InvoiceRequestFeatures,
1147
1148         /// The quantity of the offer's item conforming to [`Offer::is_valid_quantity`].
1149         pub quantity: Option<u64>,
1150
1151         /// A payer-provided note which will be seen by the recipient and reflected back in the invoice
1152         /// response. Truncated to [`PAYER_NOTE_LIMIT`] characters.
1153         pub payer_note_truncated: Option<UntrustedString>,
1154 }
1155
1156 /// The maximum number of characters included in [`InvoiceRequestFields::payer_note_truncated`].
1157 pub const PAYER_NOTE_LIMIT: usize = 512;
1158
1159 impl Writeable for InvoiceRequestFields {
1160         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
1161                 write_tlv_fields!(writer, {
1162                         (0, self.payer_id, required),
1163                         (2, self.amount_msats.map(|v| HighZeroBytesDroppedBigSize(v)), option),
1164                         (4, WithoutLength(&self.features), required),
1165                         (6, self.quantity.map(|v| HighZeroBytesDroppedBigSize(v)), option),
1166                         (8, self.payer_note_truncated.as_ref().map(|s| WithoutLength(&s.0)), option),
1167                 });
1168                 Ok(())
1169         }
1170 }
1171
1172 impl Readable for InvoiceRequestFields {
1173         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
1174                 _init_and_read_len_prefixed_tlv_fields!(reader, {
1175                         (0, payer_id, required),
1176                         (2, amount_msats, (option, encoding: (u64, HighZeroBytesDroppedBigSize))),
1177                         (4, features, (option, encoding: (InvoiceRequestFeatures, WithoutLength))),
1178                         (6, quantity, (option, encoding: (u64, HighZeroBytesDroppedBigSize))),
1179                         (8, payer_note_truncated, (option, encoding: (String, WithoutLength))),
1180                 });
1181                 let features = features.unwrap_or(InvoiceRequestFeatures::empty());
1182
1183                 Ok(InvoiceRequestFields {
1184                         payer_id: payer_id.0.unwrap(), amount_msats, features, quantity,
1185                         payer_note_truncated: payer_note_truncated.map(|s| UntrustedString(s)),
1186                 })
1187         }
1188 }
1189
1190 #[cfg(test)]
1191 mod tests {
1192         use super::{InvoiceRequest, InvoiceRequestFields, InvoiceRequestTlvStreamRef, PAYER_NOTE_LIMIT, SIGNATURE_TAG, UnsignedInvoiceRequest};
1193
1194         use bitcoin::blockdata::constants::ChainHash;
1195         use bitcoin::network::constants::Network;
1196         use bitcoin::secp256k1::{KeyPair, Secp256k1, SecretKey, self};
1197         use core::num::NonZeroU64;
1198         #[cfg(feature = "std")]
1199         use core::time::Duration;
1200         use crate::sign::KeyMaterial;
1201         use crate::ln::channelmanager::PaymentId;
1202         use crate::ln::features::{InvoiceRequestFeatures, OfferFeatures};
1203         use crate::ln::inbound_payment::ExpandedKey;
1204         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
1205         use crate::offers::invoice::{Bolt12Invoice, SIGNATURE_TAG as INVOICE_SIGNATURE_TAG};
1206         use crate::offers::merkle::{SignError, SignatureTlvStreamRef, TaggedHash, self};
1207         use crate::offers::offer::{Amount, OfferTlvStreamRef, Quantity};
1208         #[cfg(not(c_bindings))]
1209         use {
1210                 crate::offers::offer::OfferBuilder,
1211         };
1212         #[cfg(c_bindings)]
1213         use {
1214                 crate::offers::offer::OfferWithExplicitMetadataBuilder as OfferBuilder,
1215         };
1216         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
1217         use crate::offers::payer::PayerTlvStreamRef;
1218         use crate::offers::test_utils::*;
1219         use crate::util::ser::{BigSize, Readable, Writeable};
1220         use crate::util::string::{PrintableString, UntrustedString};
1221
1222         #[test]
1223         fn builds_invoice_request_with_defaults() {
1224                 let unsigned_invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1225                         .amount_msats(1000)
1226                         .build().unwrap()
1227                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1228                         .build().unwrap();
1229                 #[cfg(c_bindings)]
1230                 let mut unsigned_invoice_request = unsigned_invoice_request;
1231
1232                 let mut buffer = Vec::new();
1233                 unsigned_invoice_request.write(&mut buffer).unwrap();
1234
1235                 assert_eq!(unsigned_invoice_request.bytes, buffer.as_slice());
1236                 assert_eq!(unsigned_invoice_request.payer_metadata(), &[1; 32]);
1237                 assert_eq!(unsigned_invoice_request.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
1238                 assert_eq!(unsigned_invoice_request.metadata(), None);
1239                 assert_eq!(unsigned_invoice_request.amount(), Some(&Amount::Bitcoin { amount_msats: 1000 }));
1240                 assert_eq!(unsigned_invoice_request.description(), PrintableString("foo"));
1241                 assert_eq!(unsigned_invoice_request.offer_features(), &OfferFeatures::empty());
1242                 assert_eq!(unsigned_invoice_request.absolute_expiry(), None);
1243                 assert_eq!(unsigned_invoice_request.paths(), &[]);
1244                 assert_eq!(unsigned_invoice_request.issuer(), None);
1245                 assert_eq!(unsigned_invoice_request.supported_quantity(), Quantity::One);
1246                 assert_eq!(unsigned_invoice_request.signing_pubkey(), Some(recipient_pubkey()));
1247                 assert_eq!(unsigned_invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
1248                 assert_eq!(unsigned_invoice_request.amount_msats(), None);
1249                 assert_eq!(unsigned_invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
1250                 assert_eq!(unsigned_invoice_request.quantity(), None);
1251                 assert_eq!(unsigned_invoice_request.payer_id(), payer_pubkey());
1252                 assert_eq!(unsigned_invoice_request.payer_note(), None);
1253
1254                 match UnsignedInvoiceRequest::try_from(buffer) {
1255                         Err(e) => panic!("error parsing unsigned invoice request: {:?}", e),
1256                         Ok(parsed) => {
1257                                 assert_eq!(parsed.bytes, unsigned_invoice_request.bytes);
1258                                 assert_eq!(parsed.tagged_hash, unsigned_invoice_request.tagged_hash);
1259                         },
1260                 }
1261
1262                 let invoice_request = unsigned_invoice_request.sign(payer_sign).unwrap();
1263
1264                 let mut buffer = Vec::new();
1265                 invoice_request.write(&mut buffer).unwrap();
1266
1267                 assert_eq!(invoice_request.bytes, buffer.as_slice());
1268                 assert_eq!(invoice_request.payer_metadata(), &[1; 32]);
1269                 assert_eq!(invoice_request.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
1270                 assert_eq!(invoice_request.metadata(), None);
1271                 assert_eq!(invoice_request.amount(), Some(&Amount::Bitcoin { amount_msats: 1000 }));
1272                 assert_eq!(invoice_request.description(), PrintableString("foo"));
1273                 assert_eq!(invoice_request.offer_features(), &OfferFeatures::empty());
1274                 assert_eq!(invoice_request.absolute_expiry(), None);
1275                 assert_eq!(invoice_request.paths(), &[]);
1276                 assert_eq!(invoice_request.issuer(), None);
1277                 assert_eq!(invoice_request.supported_quantity(), Quantity::One);
1278                 assert_eq!(invoice_request.signing_pubkey(), Some(recipient_pubkey()));
1279                 assert_eq!(invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
1280                 assert_eq!(invoice_request.amount_msats(), None);
1281                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
1282                 assert_eq!(invoice_request.quantity(), None);
1283                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
1284                 assert_eq!(invoice_request.payer_note(), None);
1285
1286                 let message = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &invoice_request.bytes);
1287                 assert!(merkle::verify_signature(&invoice_request.signature, &message, payer_pubkey()).is_ok());
1288
1289                 assert_eq!(
1290                         invoice_request.as_tlv_stream(),
1291                         (
1292                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
1293                                 OfferTlvStreamRef {
1294                                         chains: None,
1295                                         metadata: None,
1296                                         currency: None,
1297                                         amount: Some(1000),
1298                                         description: Some(&String::from("foo")),
1299                                         features: None,
1300                                         absolute_expiry: None,
1301                                         paths: None,
1302                                         issuer: None,
1303                                         quantity_max: None,
1304                                         node_id: Some(&recipient_pubkey()),
1305                                 },
1306                                 InvoiceRequestTlvStreamRef {
1307                                         chain: None,
1308                                         amount: None,
1309                                         features: None,
1310                                         quantity: None,
1311                                         payer_id: Some(&payer_pubkey()),
1312                                         payer_note: None,
1313                                 },
1314                                 SignatureTlvStreamRef { signature: Some(&invoice_request.signature()) },
1315                         ),
1316                 );
1317
1318                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1319                         panic!("error parsing invoice request: {:?}", e);
1320                 }
1321         }
1322
1323         #[cfg(feature = "std")]
1324         #[test]
1325         fn builds_invoice_request_from_offer_with_expiration() {
1326                 let future_expiry = Duration::from_secs(u64::max_value());
1327                 let past_expiry = Duration::from_secs(0);
1328
1329                 if let Err(e) = OfferBuilder::new("foo".into(), recipient_pubkey())
1330                         .amount_msats(1000)
1331                         .absolute_expiry(future_expiry)
1332                         .build().unwrap()
1333                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1334                         .build()
1335                 {
1336                         panic!("error building invoice_request: {:?}", e);
1337                 }
1338
1339                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1340                         .amount_msats(1000)
1341                         .absolute_expiry(past_expiry)
1342                         .build().unwrap()
1343                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1344                         .build()
1345                 {
1346                         Ok(_) => panic!("expected error"),
1347                         Err(e) => assert_eq!(e, Bolt12SemanticError::AlreadyExpired),
1348                 }
1349         }
1350
1351         #[test]
1352         fn builds_invoice_request_with_derived_metadata() {
1353                 let payer_id = payer_pubkey();
1354                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1355                 let entropy = FixedEntropy {};
1356                 let secp_ctx = Secp256k1::new();
1357                 let payment_id = PaymentId([1; 32]);
1358
1359                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1360                         .amount_msats(1000)
1361                         .build().unwrap();
1362                 let invoice_request = offer
1363                         .request_invoice_deriving_metadata(payer_id, &expanded_key, &entropy, payment_id)
1364                         .unwrap()
1365                         .build().unwrap()
1366                         .sign(payer_sign).unwrap();
1367                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
1368
1369                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
1370                         .unwrap()
1371                         .build().unwrap()
1372                         .sign(recipient_sign).unwrap();
1373                 match invoice.verify(&expanded_key, &secp_ctx) {
1374                         Ok(payment_id) => assert_eq!(payment_id, PaymentId([1; 32])),
1375                         Err(()) => panic!("verification failed"),
1376                 }
1377
1378                 // Fails verification with altered fields
1379                 let (
1380                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
1381                         mut invoice_tlv_stream, mut signature_tlv_stream
1382                 ) = invoice.as_tlv_stream();
1383                 invoice_request_tlv_stream.amount = Some(2000);
1384                 invoice_tlv_stream.amount = Some(2000);
1385
1386                 let tlv_stream =
1387                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1388                 let mut bytes = Vec::new();
1389                 tlv_stream.write(&mut bytes).unwrap();
1390
1391                 let message = TaggedHash::from_valid_tlv_stream_bytes(INVOICE_SIGNATURE_TAG, &bytes);
1392                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1393                 signature_tlv_stream.signature = Some(&signature);
1394
1395                 let mut encoded_invoice = bytes;
1396                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1397
1398                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1399                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1400
1401                 // Fails verification with altered metadata
1402                 let (
1403                         mut payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
1404                         mut signature_tlv_stream
1405                 ) = invoice.as_tlv_stream();
1406                 let metadata = payer_tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1407                 payer_tlv_stream.metadata = Some(&metadata);
1408
1409                 let tlv_stream =
1410                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1411                 let mut bytes = Vec::new();
1412                 tlv_stream.write(&mut bytes).unwrap();
1413
1414                 let message = TaggedHash::from_valid_tlv_stream_bytes(INVOICE_SIGNATURE_TAG, &bytes);
1415                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1416                 signature_tlv_stream.signature = Some(&signature);
1417
1418                 let mut encoded_invoice = bytes;
1419                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1420
1421                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1422                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1423         }
1424
1425         #[test]
1426         fn builds_invoice_request_with_derived_payer_id() {
1427                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1428                 let entropy = FixedEntropy {};
1429                 let secp_ctx = Secp256k1::new();
1430                 let payment_id = PaymentId([1; 32]);
1431
1432                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1433                         .amount_msats(1000)
1434                         .build().unwrap();
1435                 let invoice_request = offer
1436                         .request_invoice_deriving_payer_id(&expanded_key, &entropy, &secp_ctx, payment_id)
1437                         .unwrap()
1438                         .build_and_sign()
1439                         .unwrap();
1440
1441                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
1442                         .unwrap()
1443                         .build().unwrap()
1444                         .sign(recipient_sign).unwrap();
1445                 match invoice.verify(&expanded_key, &secp_ctx) {
1446                         Ok(payment_id) => assert_eq!(payment_id, PaymentId([1; 32])),
1447                         Err(()) => panic!("verification failed"),
1448                 }
1449
1450                 // Fails verification with altered fields
1451                 let (
1452                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
1453                         mut invoice_tlv_stream, mut signature_tlv_stream
1454                 ) = invoice.as_tlv_stream();
1455                 invoice_request_tlv_stream.amount = Some(2000);
1456                 invoice_tlv_stream.amount = Some(2000);
1457
1458                 let tlv_stream =
1459                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1460                 let mut bytes = Vec::new();
1461                 tlv_stream.write(&mut bytes).unwrap();
1462
1463                 let message = TaggedHash::from_valid_tlv_stream_bytes(INVOICE_SIGNATURE_TAG, &bytes);
1464                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1465                 signature_tlv_stream.signature = Some(&signature);
1466
1467                 let mut encoded_invoice = bytes;
1468                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1469
1470                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1471                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1472
1473                 // Fails verification with altered payer id
1474                 let (
1475                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream, invoice_tlv_stream,
1476                         mut signature_tlv_stream
1477                 ) = invoice.as_tlv_stream();
1478                 let payer_id = pubkey(1);
1479                 invoice_request_tlv_stream.payer_id = Some(&payer_id);
1480
1481                 let tlv_stream =
1482                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1483                 let mut bytes = Vec::new();
1484                 tlv_stream.write(&mut bytes).unwrap();
1485
1486                 let message = TaggedHash::from_valid_tlv_stream_bytes(INVOICE_SIGNATURE_TAG, &bytes);
1487                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1488                 signature_tlv_stream.signature = Some(&signature);
1489
1490                 let mut encoded_invoice = bytes;
1491                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1492
1493                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1494                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1495         }
1496
1497         #[test]
1498         fn builds_invoice_request_with_chain() {
1499                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
1500                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
1501
1502                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1503                         .amount_msats(1000)
1504                         .build().unwrap()
1505                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1506                         .chain(Network::Bitcoin).unwrap()
1507                         .build().unwrap()
1508                         .sign(payer_sign).unwrap();
1509                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1510                 assert_eq!(invoice_request.chain(), mainnet);
1511                 assert_eq!(tlv_stream.chain, None);
1512
1513                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1514                         .amount_msats(1000)
1515                         .chain(Network::Testnet)
1516                         .build().unwrap()
1517                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1518                         .chain(Network::Testnet).unwrap()
1519                         .build().unwrap()
1520                         .sign(payer_sign).unwrap();
1521                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1522                 assert_eq!(invoice_request.chain(), testnet);
1523                 assert_eq!(tlv_stream.chain, Some(&testnet));
1524
1525                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1526                         .amount_msats(1000)
1527                         .chain(Network::Bitcoin)
1528                         .chain(Network::Testnet)
1529                         .build().unwrap()
1530                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1531                         .chain(Network::Bitcoin).unwrap()
1532                         .build().unwrap()
1533                         .sign(payer_sign).unwrap();
1534                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1535                 assert_eq!(invoice_request.chain(), mainnet);
1536                 assert_eq!(tlv_stream.chain, None);
1537
1538                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1539                         .amount_msats(1000)
1540                         .chain(Network::Bitcoin)
1541                         .chain(Network::Testnet)
1542                         .build().unwrap()
1543                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1544                         .chain(Network::Bitcoin).unwrap()
1545                         .chain(Network::Testnet).unwrap()
1546                         .build().unwrap()
1547                         .sign(payer_sign).unwrap();
1548                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1549                 assert_eq!(invoice_request.chain(), testnet);
1550                 assert_eq!(tlv_stream.chain, Some(&testnet));
1551
1552                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1553                         .amount_msats(1000)
1554                         .chain(Network::Testnet)
1555                         .build().unwrap()
1556                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1557                         .chain(Network::Bitcoin)
1558                 {
1559                         Ok(_) => panic!("expected error"),
1560                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
1561                 }
1562
1563                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1564                         .amount_msats(1000)
1565                         .chain(Network::Testnet)
1566                         .build().unwrap()
1567                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1568                         .build()
1569                 {
1570                         Ok(_) => panic!("expected error"),
1571                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
1572                 }
1573         }
1574
1575         #[test]
1576         fn builds_invoice_request_with_amount() {
1577                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1578                         .amount_msats(1000)
1579                         .build().unwrap()
1580                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1581                         .amount_msats(1000).unwrap()
1582                         .build().unwrap()
1583                         .sign(payer_sign).unwrap();
1584                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1585                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1586                 assert_eq!(tlv_stream.amount, Some(1000));
1587
1588                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1589                         .amount_msats(1000)
1590                         .build().unwrap()
1591                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1592                         .amount_msats(1001).unwrap()
1593                         .amount_msats(1000).unwrap()
1594                         .build().unwrap()
1595                         .sign(payer_sign).unwrap();
1596                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1597                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1598                 assert_eq!(tlv_stream.amount, Some(1000));
1599
1600                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1601                         .amount_msats(1000)
1602                         .build().unwrap()
1603                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1604                         .amount_msats(1001).unwrap()
1605                         .build().unwrap()
1606                         .sign(payer_sign).unwrap();
1607                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1608                 assert_eq!(invoice_request.amount_msats(), Some(1001));
1609                 assert_eq!(tlv_stream.amount, Some(1001));
1610
1611                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1612                         .amount_msats(1000)
1613                         .build().unwrap()
1614                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1615                         .amount_msats(999)
1616                 {
1617                         Ok(_) => panic!("expected error"),
1618                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1619                 }
1620
1621                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1622                         .amount_msats(1000)
1623                         .supported_quantity(Quantity::Unbounded)
1624                         .build().unwrap()
1625                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1626                         .quantity(2).unwrap()
1627                         .amount_msats(1000)
1628                 {
1629                         Ok(_) => panic!("expected error"),
1630                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1631                 }
1632
1633                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1634                         .amount_msats(1000)
1635                         .build().unwrap()
1636                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1637                         .amount_msats(MAX_VALUE_MSAT + 1)
1638                 {
1639                         Ok(_) => panic!("expected error"),
1640                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1641                 }
1642
1643                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1644                         .amount_msats(1000)
1645                         .supported_quantity(Quantity::Unbounded)
1646                         .build().unwrap()
1647                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1648                         .amount_msats(1000).unwrap()
1649                         .quantity(2).unwrap()
1650                         .build()
1651                 {
1652                         Ok(_) => panic!("expected error"),
1653                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1654                 }
1655
1656                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1657                         .build().unwrap()
1658                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1659                         .build()
1660                 {
1661                         Ok(_) => panic!("expected error"),
1662                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingAmount),
1663                 }
1664
1665                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1666                         .amount_msats(1000)
1667                         .supported_quantity(Quantity::Unbounded)
1668                         .build().unwrap()
1669                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1670                         .quantity(u64::max_value()).unwrap()
1671                         .build()
1672                 {
1673                         Ok(_) => panic!("expected error"),
1674                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1675                 }
1676         }
1677
1678         #[test]
1679         fn builds_invoice_request_with_features() {
1680                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1681                         .amount_msats(1000)
1682                         .build().unwrap()
1683                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1684                         .features_unchecked(InvoiceRequestFeatures::unknown())
1685                         .build().unwrap()
1686                         .sign(payer_sign).unwrap();
1687                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1688                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::unknown());
1689                 assert_eq!(tlv_stream.features, Some(&InvoiceRequestFeatures::unknown()));
1690
1691                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1692                         .amount_msats(1000)
1693                         .build().unwrap()
1694                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1695                         .features_unchecked(InvoiceRequestFeatures::unknown())
1696                         .features_unchecked(InvoiceRequestFeatures::empty())
1697                         .build().unwrap()
1698                         .sign(payer_sign).unwrap();
1699                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1700                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
1701                 assert_eq!(tlv_stream.features, None);
1702         }
1703
1704         #[test]
1705         fn builds_invoice_request_with_quantity() {
1706                 let one = NonZeroU64::new(1).unwrap();
1707                 let ten = NonZeroU64::new(10).unwrap();
1708
1709                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1710                         .amount_msats(1000)
1711                         .supported_quantity(Quantity::One)
1712                         .build().unwrap()
1713                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1714                         .build().unwrap()
1715                         .sign(payer_sign).unwrap();
1716                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1717                 assert_eq!(invoice_request.quantity(), None);
1718                 assert_eq!(tlv_stream.quantity, None);
1719
1720                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1721                         .amount_msats(1000)
1722                         .supported_quantity(Quantity::One)
1723                         .build().unwrap()
1724                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1725                         .amount_msats(2_000).unwrap()
1726                         .quantity(2)
1727                 {
1728                         Ok(_) => panic!("expected error"),
1729                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnexpectedQuantity),
1730                 }
1731
1732                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1733                         .amount_msats(1000)
1734                         .supported_quantity(Quantity::Bounded(ten))
1735                         .build().unwrap()
1736                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1737                         .amount_msats(10_000).unwrap()
1738                         .quantity(10).unwrap()
1739                         .build().unwrap()
1740                         .sign(payer_sign).unwrap();
1741                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1742                 assert_eq!(invoice_request.amount_msats(), Some(10_000));
1743                 assert_eq!(tlv_stream.amount, Some(10_000));
1744
1745                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1746                         .amount_msats(1000)
1747                         .supported_quantity(Quantity::Bounded(ten))
1748                         .build().unwrap()
1749                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1750                         .amount_msats(11_000).unwrap()
1751                         .quantity(11)
1752                 {
1753                         Ok(_) => panic!("expected error"),
1754                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidQuantity),
1755                 }
1756
1757                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1758                         .amount_msats(1000)
1759                         .supported_quantity(Quantity::Unbounded)
1760                         .build().unwrap()
1761                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1762                         .amount_msats(2_000).unwrap()
1763                         .quantity(2).unwrap()
1764                         .build().unwrap()
1765                         .sign(payer_sign).unwrap();
1766                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1767                 assert_eq!(invoice_request.amount_msats(), Some(2_000));
1768                 assert_eq!(tlv_stream.amount, Some(2_000));
1769
1770                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1771                         .amount_msats(1000)
1772                         .supported_quantity(Quantity::Unbounded)
1773                         .build().unwrap()
1774                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1775                         .build()
1776                 {
1777                         Ok(_) => panic!("expected error"),
1778                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
1779                 }
1780
1781                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1782                         .amount_msats(1000)
1783                         .supported_quantity(Quantity::Bounded(one))
1784                         .build().unwrap()
1785                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1786                         .build()
1787                 {
1788                         Ok(_) => panic!("expected error"),
1789                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
1790                 }
1791         }
1792
1793         #[test]
1794         fn builds_invoice_request_with_payer_note() {
1795                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1796                         .amount_msats(1000)
1797                         .build().unwrap()
1798                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1799                         .payer_note("bar".into())
1800                         .build().unwrap()
1801                         .sign(payer_sign).unwrap();
1802                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1803                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("bar")));
1804                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
1805
1806                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1807                         .amount_msats(1000)
1808                         .build().unwrap()
1809                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1810                         .payer_note("bar".into())
1811                         .payer_note("baz".into())
1812                         .build().unwrap()
1813                         .sign(payer_sign).unwrap();
1814                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1815                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("baz")));
1816                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
1817         }
1818
1819         #[test]
1820         fn fails_signing_invoice_request() {
1821                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1822                         .amount_msats(1000)
1823                         .build().unwrap()
1824                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1825                         .build().unwrap()
1826                         .sign(fail_sign)
1827                 {
1828                         Ok(_) => panic!("expected error"),
1829                         Err(e) => assert_eq!(e, SignError::Signing),
1830                 }
1831
1832                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1833                         .amount_msats(1000)
1834                         .build().unwrap()
1835                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1836                         .build().unwrap()
1837                         .sign(recipient_sign)
1838                 {
1839                         Ok(_) => panic!("expected error"),
1840                         Err(e) => assert_eq!(e, SignError::Verification(secp256k1::Error::InvalidSignature)),
1841                 }
1842         }
1843
1844         #[test]
1845         fn fails_responding_with_unknown_required_features() {
1846                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1847                         .amount_msats(1000)
1848                         .build().unwrap()
1849                         .request_invoice(vec![42; 32], payer_pubkey()).unwrap()
1850                         .features_unchecked(InvoiceRequestFeatures::unknown())
1851                         .build().unwrap()
1852                         .sign(payer_sign).unwrap()
1853                         .respond_with_no_std(payment_paths(), payment_hash(), now())
1854                 {
1855                         Ok(_) => panic!("expected error"),
1856                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1857                 }
1858         }
1859
1860         #[test]
1861         fn parses_invoice_request_with_metadata() {
1862                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1863                         .amount_msats(1000)
1864                         .build().unwrap()
1865                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1866                         .build().unwrap()
1867                         .sign(payer_sign).unwrap();
1868
1869                 let mut buffer = Vec::new();
1870                 invoice_request.write(&mut buffer).unwrap();
1871
1872                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1873                         panic!("error parsing invoice_request: {:?}", e);
1874                 }
1875         }
1876
1877         #[test]
1878         fn parses_invoice_request_with_chain() {
1879                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1880                         .amount_msats(1000)
1881                         .build().unwrap()
1882                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1883                         .chain(Network::Bitcoin).unwrap()
1884                         .build().unwrap()
1885                         .sign(payer_sign).unwrap();
1886
1887                 let mut buffer = Vec::new();
1888                 invoice_request.write(&mut buffer).unwrap();
1889
1890                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1891                         panic!("error parsing invoice_request: {:?}", e);
1892                 }
1893
1894                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1895                         .amount_msats(1000)
1896                         .build().unwrap()
1897                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1898                         .chain_unchecked(Network::Testnet)
1899                         .build_unchecked()
1900                         .sign(payer_sign).unwrap();
1901
1902                 let mut buffer = Vec::new();
1903                 invoice_request.write(&mut buffer).unwrap();
1904
1905                 match InvoiceRequest::try_from(buffer) {
1906                         Ok(_) => panic!("expected error"),
1907                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnsupportedChain)),
1908                 }
1909         }
1910
1911         #[test]
1912         fn parses_invoice_request_with_amount() {
1913                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1914                         .amount_msats(1000)
1915                         .build().unwrap()
1916                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1917                         .build().unwrap()
1918                         .sign(payer_sign).unwrap();
1919
1920                 let mut buffer = Vec::new();
1921                 invoice_request.write(&mut buffer).unwrap();
1922
1923                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1924                         panic!("error parsing invoice_request: {:?}", e);
1925                 }
1926
1927                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1928                         .build().unwrap()
1929                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1930                         .amount_msats(1000).unwrap()
1931                         .build().unwrap()
1932                         .sign(payer_sign).unwrap();
1933
1934                 let mut buffer = Vec::new();
1935                 invoice_request.write(&mut buffer).unwrap();
1936
1937                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1938                         panic!("error parsing invoice_request: {:?}", e);
1939                 }
1940
1941                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1942                         .build().unwrap()
1943                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1944                         .build_unchecked()
1945                         .sign(payer_sign).unwrap();
1946
1947                 let mut buffer = Vec::new();
1948                 invoice_request.write(&mut buffer).unwrap();
1949
1950                 match InvoiceRequest::try_from(buffer) {
1951                         Ok(_) => panic!("expected error"),
1952                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1953                 }
1954
1955                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1956                         .amount_msats(1000)
1957                         .build().unwrap()
1958                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1959                         .amount_msats_unchecked(999)
1960                         .build_unchecked()
1961                         .sign(payer_sign).unwrap();
1962
1963                 let mut buffer = Vec::new();
1964                 invoice_request.write(&mut buffer).unwrap();
1965
1966                 match InvoiceRequest::try_from(buffer) {
1967                         Ok(_) => panic!("expected error"),
1968                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InsufficientAmount)),
1969                 }
1970
1971                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1972                         .amount(Amount::Currency { iso4217_code: *b"USD", amount: 1000 })
1973                         .build_unchecked()
1974                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1975                         .build_unchecked()
1976                         .sign(payer_sign).unwrap();
1977
1978                 let mut buffer = Vec::new();
1979                 invoice_request.write(&mut buffer).unwrap();
1980
1981                 match InvoiceRequest::try_from(buffer) {
1982                         Ok(_) => panic!("expected error"),
1983                         Err(e) => {
1984                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnsupportedCurrency));
1985                         },
1986                 }
1987
1988                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1989                         .amount_msats(1000)
1990                         .supported_quantity(Quantity::Unbounded)
1991                         .build().unwrap()
1992                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1993                         .quantity(u64::max_value()).unwrap()
1994                         .build_unchecked()
1995                         .sign(payer_sign).unwrap();
1996
1997                 let mut buffer = Vec::new();
1998                 invoice_request.write(&mut buffer).unwrap();
1999
2000                 match InvoiceRequest::try_from(buffer) {
2001                         Ok(_) => panic!("expected error"),
2002                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
2003                 }
2004         }
2005
2006         #[test]
2007         fn parses_invoice_request_with_quantity() {
2008                 let one = NonZeroU64::new(1).unwrap();
2009                 let ten = NonZeroU64::new(10).unwrap();
2010
2011                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2012                         .amount_msats(1000)
2013                         .supported_quantity(Quantity::One)
2014                         .build().unwrap()
2015                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2016                         .build().unwrap()
2017                         .sign(payer_sign).unwrap();
2018
2019                 let mut buffer = Vec::new();
2020                 invoice_request.write(&mut buffer).unwrap();
2021
2022                 if let Err(e) = InvoiceRequest::try_from(buffer) {
2023                         panic!("error parsing invoice_request: {:?}", e);
2024                 }
2025
2026                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2027                         .amount_msats(1000)
2028                         .supported_quantity(Quantity::One)
2029                         .build().unwrap()
2030                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2031                         .amount_msats(2_000).unwrap()
2032                         .quantity_unchecked(2)
2033                         .build_unchecked()
2034                         .sign(payer_sign).unwrap();
2035
2036                 let mut buffer = Vec::new();
2037                 invoice_request.write(&mut buffer).unwrap();
2038
2039                 match InvoiceRequest::try_from(buffer) {
2040                         Ok(_) => panic!("expected error"),
2041                         Err(e) => {
2042                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnexpectedQuantity));
2043                         },
2044                 }
2045
2046                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2047                         .amount_msats(1000)
2048                         .supported_quantity(Quantity::Bounded(ten))
2049                         .build().unwrap()
2050                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2051                         .amount_msats(10_000).unwrap()
2052                         .quantity(10).unwrap()
2053                         .build().unwrap()
2054                         .sign(payer_sign).unwrap();
2055
2056                 let mut buffer = Vec::new();
2057                 invoice_request.write(&mut buffer).unwrap();
2058
2059                 if let Err(e) = InvoiceRequest::try_from(buffer) {
2060                         panic!("error parsing invoice_request: {:?}", e);
2061                 }
2062
2063                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2064                         .amount_msats(1000)
2065                         .supported_quantity(Quantity::Bounded(ten))
2066                         .build().unwrap()
2067                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2068                         .amount_msats(11_000).unwrap()
2069                         .quantity_unchecked(11)
2070                         .build_unchecked()
2071                         .sign(payer_sign).unwrap();
2072
2073                 let mut buffer = Vec::new();
2074                 invoice_request.write(&mut buffer).unwrap();
2075
2076                 match InvoiceRequest::try_from(buffer) {
2077                         Ok(_) => panic!("expected error"),
2078                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidQuantity)),
2079                 }
2080
2081                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2082                         .amount_msats(1000)
2083                         .supported_quantity(Quantity::Unbounded)
2084                         .build().unwrap()
2085                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2086                         .amount_msats(2_000).unwrap()
2087                         .quantity(2).unwrap()
2088                         .build().unwrap()
2089                         .sign(payer_sign).unwrap();
2090
2091                 let mut buffer = Vec::new();
2092                 invoice_request.write(&mut buffer).unwrap();
2093
2094                 if let Err(e) = InvoiceRequest::try_from(buffer) {
2095                         panic!("error parsing invoice_request: {:?}", e);
2096                 }
2097
2098                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2099                         .amount_msats(1000)
2100                         .supported_quantity(Quantity::Unbounded)
2101                         .build().unwrap()
2102                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2103                         .build_unchecked()
2104                         .sign(payer_sign).unwrap();
2105
2106                 let mut buffer = Vec::new();
2107                 invoice_request.write(&mut buffer).unwrap();
2108
2109                 match InvoiceRequest::try_from(buffer) {
2110                         Ok(_) => panic!("expected error"),
2111                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
2112                 }
2113
2114                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2115                         .amount_msats(1000)
2116                         .supported_quantity(Quantity::Bounded(one))
2117                         .build().unwrap()
2118                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2119                         .build_unchecked()
2120                         .sign(payer_sign).unwrap();
2121
2122                 let mut buffer = Vec::new();
2123                 invoice_request.write(&mut buffer).unwrap();
2124
2125                 match InvoiceRequest::try_from(buffer) {
2126                         Ok(_) => panic!("expected error"),
2127                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
2128                 }
2129         }
2130
2131         #[test]
2132         fn fails_parsing_invoice_request_without_metadata() {
2133                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
2134                         .amount_msats(1000)
2135                         .build().unwrap();
2136                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2137                         .build().unwrap();
2138                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
2139                 tlv_stream.0.metadata = None;
2140
2141                 let mut buffer = Vec::new();
2142                 tlv_stream.write(&mut buffer).unwrap();
2143
2144                 match InvoiceRequest::try_from(buffer) {
2145                         Ok(_) => panic!("expected error"),
2146                         Err(e) => {
2147                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPayerMetadata));
2148                         },
2149                 }
2150         }
2151
2152         #[test]
2153         fn fails_parsing_invoice_request_without_payer_id() {
2154                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
2155                         .amount_msats(1000)
2156                         .build().unwrap();
2157                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2158                         .build().unwrap();
2159                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
2160                 tlv_stream.2.payer_id = None;
2161
2162                 let mut buffer = Vec::new();
2163                 tlv_stream.write(&mut buffer).unwrap();
2164
2165                 match InvoiceRequest::try_from(buffer) {
2166                         Ok(_) => panic!("expected error"),
2167                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPayerId)),
2168                 }
2169         }
2170
2171         #[test]
2172         fn fails_parsing_invoice_request_without_node_id() {
2173                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
2174                         .amount_msats(1000)
2175                         .build().unwrap();
2176                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2177                         .build().unwrap();
2178                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
2179                 tlv_stream.1.node_id = None;
2180
2181                 let mut buffer = Vec::new();
2182                 tlv_stream.write(&mut buffer).unwrap();
2183
2184                 match InvoiceRequest::try_from(buffer) {
2185                         Ok(_) => panic!("expected error"),
2186                         Err(e) => {
2187                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
2188                         },
2189                 }
2190         }
2191
2192         #[test]
2193         fn fails_parsing_invoice_request_without_signature() {
2194                 let mut buffer = Vec::new();
2195                 OfferBuilder::new("foo".into(), recipient_pubkey())
2196                         .amount_msats(1000)
2197                         .build().unwrap()
2198                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2199                         .build().unwrap()
2200                         .contents
2201                         .write(&mut buffer).unwrap();
2202
2203                 match InvoiceRequest::try_from(buffer) {
2204                         Ok(_) => panic!("expected error"),
2205                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
2206                 }
2207         }
2208
2209         #[test]
2210         fn fails_parsing_invoice_request_with_invalid_signature() {
2211                 let mut invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2212                         .amount_msats(1000)
2213                         .build().unwrap()
2214                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2215                         .build().unwrap()
2216                         .sign(payer_sign).unwrap();
2217                 let last_signature_byte = invoice_request.bytes.last_mut().unwrap();
2218                 *last_signature_byte = last_signature_byte.wrapping_add(1);
2219
2220                 let mut buffer = Vec::new();
2221                 invoice_request.write(&mut buffer).unwrap();
2222
2223                 match InvoiceRequest::try_from(buffer) {
2224                         Ok(_) => panic!("expected error"),
2225                         Err(e) => {
2226                                 assert_eq!(e, Bolt12ParseError::InvalidSignature(secp256k1::Error::InvalidSignature));
2227                         },
2228                 }
2229         }
2230
2231         #[test]
2232         fn fails_parsing_invoice_request_with_extra_tlv_records() {
2233                 let secp_ctx = Secp256k1::new();
2234                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2235                 let invoice_request = OfferBuilder::new("foo".into(), keys.public_key())
2236                         .amount_msats(1000)
2237                         .build().unwrap()
2238                         .request_invoice(vec![1; 32], keys.public_key()).unwrap()
2239                         .build().unwrap()
2240                         .sign(|message: &UnsignedInvoiceRequest|
2241                                 Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
2242                         )
2243                         .unwrap();
2244
2245                 let mut encoded_invoice_request = Vec::new();
2246                 invoice_request.write(&mut encoded_invoice_request).unwrap();
2247                 BigSize(1002).write(&mut encoded_invoice_request).unwrap();
2248                 BigSize(32).write(&mut encoded_invoice_request).unwrap();
2249                 [42u8; 32].write(&mut encoded_invoice_request).unwrap();
2250
2251                 match InvoiceRequest::try_from(encoded_invoice_request) {
2252                         Ok(_) => panic!("expected error"),
2253                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
2254                 }
2255         }
2256
2257         #[test]
2258         fn copies_verified_invoice_request_fields() {
2259                 let desc = "foo".to_string();
2260                 let node_id = recipient_pubkey();
2261                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
2262                 let entropy = FixedEntropy {};
2263                 let secp_ctx = Secp256k1::new();
2264
2265                 #[cfg(c_bindings)]
2266                 use crate::offers::offer::OfferWithDerivedMetadataBuilder as OfferBuilder;
2267                 let offer = OfferBuilder
2268                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
2269                         .chain(Network::Testnet)
2270                         .amount_msats(1000)
2271                         .supported_quantity(Quantity::Unbounded)
2272                         .build().unwrap();
2273                 assert_eq!(offer.signing_pubkey(), Some(node_id));
2274
2275                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2276                         .chain(Network::Testnet).unwrap()
2277                         .amount_msats(1001).unwrap()
2278                         .quantity(1).unwrap()
2279                         .payer_note("0".repeat(PAYER_NOTE_LIMIT * 2))
2280                         .build().unwrap()
2281                         .sign(payer_sign).unwrap();
2282                 match invoice_request.verify(&expanded_key, &secp_ctx) {
2283                         Ok(invoice_request) => {
2284                                 let fields = invoice_request.fields();
2285                                 assert_eq!(invoice_request.offer_id, offer.id());
2286                                 assert_eq!(
2287                                         fields,
2288                                         InvoiceRequestFields {
2289                                                 payer_id: payer_pubkey(),
2290                                                 amount_msats: Some(1001),
2291                                                 features: InvoiceRequestFeatures::empty(),
2292                                                 quantity: Some(1),
2293                                                 payer_note_truncated: Some(UntrustedString("0".repeat(PAYER_NOTE_LIMIT))),
2294                                         }
2295                                 );
2296
2297                                 let mut buffer = Vec::new();
2298                                 fields.write(&mut buffer).unwrap();
2299
2300                                 let deserialized_fields: InvoiceRequestFields =
2301                                         Readable::read(&mut buffer.as_slice()).unwrap();
2302                                 assert_eq!(deserialized_fields, fields);
2303                         },
2304                         Err(_) => panic!("unexpected error"),
2305                 }
2306         }
2307 }