_ 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 $contents.invoice_request_features().requires_unknown_bits() {
 747                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 748                 }
 749
 750                 <$builder>::for_offer(&$contents, payment_paths, created_at, payment_hash)
 751         }
 752 } }
 753
 754 macro_rules! invoice_request_verify_method { ($self: ident, $self_type: ty) => {
 755         /// Verifies that the request was for an offer created using the given key. Returns the verified
 756         /// request which contains the derived keys needed to sign a [`Bolt12Invoice`] for the request
 757         /// if they could be extracted from the metadata.
 758         ///
 759         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 760         pub fn verify<
 761                 #[cfg(not(c_bindings))]
 762                 T: secp256k1::Signing
 763         >(
 764                 $self: $self_type, key: &ExpandedKey,
 765                 #[cfg(not(c_bindings))]
 766                 secp_ctx: &Secp256k1<T>,
 767                 #[cfg(c_bindings)]
 768                 secp_ctx: &Secp256k1<secp256k1::All>,
 769         ) -> Result<VerifiedInvoiceRequest, ()> {
 770                 let (offer_id, keys) = $self.contents.inner.offer.verify(&$self.bytes, key, secp_ctx)?;
 771                 Ok(VerifiedInvoiceRequest {
 772                         offer_id,
 773                         #[cfg(not(c_bindings))]
 774                         inner: $self,
 775                         #[cfg(c_bindings)]
 776                         inner: $self.clone(),
 777                         keys,
 778                 })
 779         }
 780
 781 } }
 782
 783 #[cfg(not(c_bindings))]
 784 impl InvoiceRequest {
 785         offer_accessors!(self, self.contents.inner.offer);
 786         invoice_request_accessors!(self, self.contents);
 787         invoice_request_respond_with_explicit_signing_pubkey_methods!(self, self, InvoiceBuilder<ExplicitSigningPubkey>);
 788         invoice_request_verify_method!(self, Self);
 789 }
 790
 791 #[cfg(c_bindings)]
 792 impl InvoiceRequest {
 793         offer_accessors!(self, self.contents.inner.offer);
 794         invoice_request_accessors!(self, self.contents);
 795         invoice_request_respond_with_explicit_signing_pubkey_methods!(self, self, InvoiceWithExplicitSigningPubkeyBuilder);
 796         invoice_request_verify_method!(self, &Self);
 797 }
 798
 799 impl InvoiceRequest {
 800         /// Signature of the invoice request using [`payer_id`].
 801         ///
 802         /// [`payer_id`]: Self::payer_id
 803         pub fn signature(&self) -> Signature {
 804                 self.signature
 805         }
 806
 807         pub(crate) fn as_tlv_stream(&self) -> FullInvoiceRequestTlvStreamRef {
 808                 let (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream) =
 809                         self.contents.as_tlv_stream();
 810                 let signature_tlv_stream = SignatureTlvStreamRef {
 811                         signature: Some(&self.signature),
 812                 };
 813                 (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, signature_tlv_stream)
 814         }
 815 }
 816
 817 macro_rules! invoice_request_respond_with_derived_signing_pubkey_methods { (
 818         $self: ident, $contents: expr, $builder: ty
 819 ) => {
 820         /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
 821         /// derived signing keys from the originating [`Offer`] to sign the [`Bolt12Invoice`]. Must use
 822         /// the same [`ExpandedKey`] as the one used to create the offer.
 823         ///
 824         /// See [`InvoiceRequest::respond_with`] for further details.
 825         ///
 826         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 827         #[cfg(feature = "std")]
 828         pub fn respond_using_derived_keys(
 829                 &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash
 830         ) -> Result<$builder, Bolt12SemanticError> {
 831                 let created_at = std::time::SystemTime::now()
 832                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 833                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 834
 835                 $self.respond_using_derived_keys_no_std(payment_paths, payment_hash, created_at)
 836         }
 837
 838         /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
 839         /// derived signing keys from the originating [`Offer`] to sign the [`Bolt12Invoice`]. Must use
 840         /// the same [`ExpandedKey`] as the one used to create the offer.
 841         ///
 842         /// See [`InvoiceRequest::respond_with_no_std`] for further details.
 843         ///
 844         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 845         pub fn respond_using_derived_keys_no_std(
 846                 &$self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 847                 created_at: core::time::Duration
 848         ) -> Result<$builder, Bolt12SemanticError> {
 849                 if $self.inner.invoice_request_features().requires_unknown_bits() {
 850                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 851                 }
 852
 853                 let keys = match $self.keys {
 854                         None => return Err(Bolt12SemanticError::InvalidMetadata),
 855                         Some(keys) => keys,
 856                 };
 857
 858                 <$builder>::for_offer_using_keys(
 859                         &$self.inner, payment_paths, created_at, payment_hash, keys
 860                 )
 861         }
 862 } }
 863
 864 impl VerifiedInvoiceRequest {
 865         offer_accessors!(self, self.inner.contents.inner.offer);
 866         invoice_request_accessors!(self, self.inner.contents);
 867         #[cfg(not(c_bindings))]
 868         invoice_request_respond_with_explicit_signing_pubkey_methods!(self, self.inner, InvoiceBuilder<ExplicitSigningPubkey>);
 869         #[cfg(c_bindings)]
 870         invoice_request_respond_with_explicit_signing_pubkey_methods!(self, self.inner, InvoiceWithExplicitSigningPubkeyBuilder);
 871         #[cfg(not(c_bindings))]
 872         invoice_request_respond_with_derived_signing_pubkey_methods!(self, self.inner, InvoiceBuilder<DerivedSigningPubkey>);
 873         #[cfg(c_bindings)]
 874         invoice_request_respond_with_derived_signing_pubkey_methods!(self, self.inner, InvoiceWithDerivedSigningPubkeyBuilder);
 875
 876         pub(crate) fn fields(&self) -> InvoiceRequestFields {
 877                 let InvoiceRequestContents {
 878                         payer_id,
 879                         inner: InvoiceRequestContentsWithoutPayerId {
 880                                 payer: _, offer: _, chain: _, amount_msats: _, features, quantity, payer_note
 881                         },
 882                 } = &self.inner.contents;
 883
 884                 InvoiceRequestFields {
 885                         payer_id: *payer_id,
 886                         features: features.clone(),
 887                         quantity: *quantity,
 888                         payer_note_truncated: payer_note.clone()
 889                                 .map(|mut s| { s.truncate(PAYER_NOTE_LIMIT); UntrustedString(s) }),
 890                 }
 891         }
 892 }
 893
 894 impl InvoiceRequestContents {
 895         pub(super) fn metadata(&self) -> &[u8] {
 896                 self.inner.metadata()
 897         }
 898
 899         pub(super) fn derives_keys(&self) -> bool {
 900                 self.inner.payer.0.derives_payer_keys()
 901         }
 902
 903         pub(super) fn chain(&self) -> ChainHash {
 904                 self.inner.chain()
 905         }
 906
 907         pub(super) fn amount_msats(&self) -> Option<u64> {
 908                 self.inner.amount_msats
 909         }
 910
 911         pub(super) fn features(&self) -> &InvoiceRequestFeatures {
 912                 &self.inner.features
 913         }
 914
 915         pub(super) fn quantity(&self) -> Option<u64> {
 916                 self.inner.quantity
 917         }
 918
 919         pub(super) fn payer_id(&self) -> PublicKey {
 920                 self.payer_id
 921         }
 922
 923         pub(super) fn payer_note(&self) -> Option<PrintableString> {
 924                 self.inner.payer_note.as_ref()
 925                         .map(|payer_note| PrintableString(payer_note.as_str()))
 926         }
 927
 928         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 929                 let (payer, offer, mut invoice_request) = self.inner.as_tlv_stream();
 930                 invoice_request.payer_id = Some(&self.payer_id);
 931                 (payer, offer, invoice_request)
 932         }
 933 }
 934
 935 impl InvoiceRequestContentsWithoutPayerId {
 936         pub(super) fn metadata(&self) -> &[u8] {
 937                 self.payer.0.as_bytes().map(|bytes| bytes.as_slice()).unwrap_or(&[])
 938         }
 939
 940         pub(super) fn chain(&self) -> ChainHash {
 941                 self.chain.unwrap_or_else(|| self.offer.implied_chain())
 942         }
 943
 944         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 945                 let payer = PayerTlvStreamRef {
 946                         metadata: self.payer.0.as_bytes(),
 947                 };
 948
 949                 let offer = self.offer.as_tlv_stream();
 950
 951                 let features = {
 952                         if self.features == InvoiceRequestFeatures::empty() { None }
 953                         else { Some(&self.features) }
 954                 };
 955
 956                 let invoice_request = InvoiceRequestTlvStreamRef {
 957                         chain: self.chain.as_ref(),
 958                         amount: self.amount_msats,
 959                         features,
 960                         quantity: self.quantity,
 961                         payer_id: None,
 962                         payer_note: self.payer_note.as_ref(),
 963                 };
 964
 965                 (payer, offer, invoice_request)
 966         }
 967 }
 968
 969 impl Writeable for UnsignedInvoiceRequest {
 970         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 971                 WithoutLength(&self.bytes).write(writer)
 972         }
 973 }
 974
 975 impl Writeable for InvoiceRequest {
 976         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 977                 WithoutLength(&self.bytes).write(writer)
 978         }
 979 }
 980
 981 impl Writeable for InvoiceRequestContents {
 982         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 983                 self.as_tlv_stream().write(writer)
 984         }
 985 }
 986
 987 /// Valid type range for invoice_request TLV records.
 988 pub(super) const INVOICE_REQUEST_TYPES: core::ops::Range<u64> = 80..160;
 989
 990 /// TLV record type for [`InvoiceRequest::payer_id`] and [`Refund::payer_id`].
 991 ///
 992 /// [`Refund::payer_id`]: crate::offers::refund::Refund::payer_id
 993 pub(super) const INVOICE_REQUEST_PAYER_ID_TYPE: u64 = 88;
 994
 995 tlv_stream!(InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef, INVOICE_REQUEST_TYPES, {
 996         (80, chain: ChainHash),
 997         (82, amount: (u64, HighZeroBytesDroppedBigSize)),
 998         (84, features: (InvoiceRequestFeatures, WithoutLength)),
 999         (86, quantity: (u64, HighZeroBytesDroppedBigSize)),
1000         (INVOICE_REQUEST_PAYER_ID_TYPE, payer_id: PublicKey),
1001         (89, payer_note: (String, WithoutLength)),
1002 });
1003
1004 type FullInvoiceRequestTlvStream =
1005         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, SignatureTlvStream);
1006
1007 type FullInvoiceRequestTlvStreamRef<'a> = (
1008         PayerTlvStreamRef<'a>,
1009         OfferTlvStreamRef<'a>,
1010         InvoiceRequestTlvStreamRef<'a>,
1011         SignatureTlvStreamRef<'a>,
1012 );
1013
1014 impl SeekReadable for FullInvoiceRequestTlvStream {
1015         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
1016                 let payer = SeekReadable::read(r)?;
1017                 let offer = SeekReadable::read(r)?;
1018                 let invoice_request = SeekReadable::read(r)?;
1019                 let signature = SeekReadable::read(r)?;
1020
1021                 Ok((payer, offer, invoice_request, signature))
1022         }
1023 }
1024
1025 type PartialInvoiceRequestTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
1026
1027 type PartialInvoiceRequestTlvStreamRef<'a> = (
1028         PayerTlvStreamRef<'a>,
1029         OfferTlvStreamRef<'a>,
1030         InvoiceRequestTlvStreamRef<'a>,
1031 );
1032
1033 impl TryFrom<Vec<u8>> for UnsignedInvoiceRequest {
1034         type Error = Bolt12ParseError;
1035
1036         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
1037                 let invoice_request = ParsedMessage::<PartialInvoiceRequestTlvStream>::try_from(bytes)?;
1038                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
1039                 let (
1040                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
1041                 ) = tlv_stream;
1042                 let contents = InvoiceRequestContents::try_from(
1043                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
1044                 )?;
1045
1046                 let tagged_hash = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &bytes);
1047
1048                 Ok(UnsignedInvoiceRequest { bytes, contents, tagged_hash })
1049         }
1050 }
1051
1052 impl TryFrom<Vec<u8>> for InvoiceRequest {
1053         type Error = Bolt12ParseError;
1054
1055         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
1056                 let invoice_request = ParsedMessage::<FullInvoiceRequestTlvStream>::try_from(bytes)?;
1057                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
1058                 let (
1059                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
1060                         SignatureTlvStream { signature },
1061                 ) = tlv_stream;
1062                 let contents = InvoiceRequestContents::try_from(
1063                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
1064                 )?;
1065
1066                 let signature = match signature {
1067                         None => return Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
1068                         Some(signature) => signature,
1069                 };
1070                 let message = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &bytes);
1071                 merkle::verify_signature(&signature, &message, contents.payer_id)?;
1072
1073                 Ok(InvoiceRequest { bytes, contents, signature })
1074         }
1075 }
1076
1077 impl TryFrom<PartialInvoiceRequestTlvStream> for InvoiceRequestContents {
1078         type Error = Bolt12SemanticError;
1079
1080         fn try_from(tlv_stream: PartialInvoiceRequestTlvStream) -> Result<Self, Self::Error> {
1081                 let (
1082                         PayerTlvStream { metadata },
1083                         offer_tlv_stream,
1084                         InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
1085                 ) = tlv_stream;
1086
1087                 let payer = match metadata {
1088                         None => return Err(Bolt12SemanticError::MissingPayerMetadata),
1089                         Some(metadata) => PayerContents(Metadata::Bytes(metadata)),
1090                 };
1091                 let offer = OfferContents::try_from(offer_tlv_stream)?;
1092
1093                 if !offer.supports_chain(chain.unwrap_or_else(|| offer.implied_chain())) {
1094                         return Err(Bolt12SemanticError::UnsupportedChain);
1095                 }
1096
1097                 if offer.amount().is_none() && amount.is_none() {
1098                         return Err(Bolt12SemanticError::MissingAmount);
1099                 }
1100
1101                 offer.check_quantity(quantity)?;
1102                 offer.check_amount_msats_for_quantity(amount, quantity)?;
1103
1104                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
1105
1106                 let payer_id = match payer_id {
1107                         None => return Err(Bolt12SemanticError::MissingPayerId),
1108                         Some(payer_id) => payer_id,
1109                 };
1110
1111                 Ok(InvoiceRequestContents {
1112                         inner: InvoiceRequestContentsWithoutPayerId {
1113                                 payer, offer, chain, amount_msats: amount, features, quantity, payer_note,
1114                         },
1115                         payer_id,
1116                 })
1117         }
1118 }
1119
1120 /// Fields sent in an [`InvoiceRequest`] message to include in [`PaymentContext::Bolt12Offer`].
1121 ///
1122 /// [`PaymentContext::Bolt12Offer`]: crate::blinded_path::payment::PaymentContext::Bolt12Offer
1123 #[derive(Clone, Debug, Eq, PartialEq)]
1124 pub struct InvoiceRequestFields {
1125         /// A possibly transient pubkey used to sign the invoice request.
1126         pub payer_id: PublicKey,
1127
1128         /// Features pertaining to requesting an invoice.
1129         pub features: InvoiceRequestFeatures,
1130
1131         /// The quantity of the offer's item conforming to [`Offer::is_valid_quantity`].
1132         pub quantity: Option<u64>,
1133
1134         /// A payer-provided note which will be seen by the recipient and reflected back in the invoice
1135         /// response. Truncated to [`PAYER_NOTE_LIMIT`] characters.
1136         pub payer_note_truncated: Option<UntrustedString>,
1137 }
1138
1139 /// The maximum number of characters included in [`InvoiceRequestFields::payer_note_truncated`].
1140 pub const PAYER_NOTE_LIMIT: usize = 512;
1141
1142 impl Writeable for InvoiceRequestFields {
1143         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
1144                 write_tlv_fields!(writer, {
1145                         (0, self.payer_id, required),
1146                         (2, WithoutLength(&self.features), required),
1147                         (4, self.quantity.map(|v| HighZeroBytesDroppedBigSize(v)), option),
1148                         (6, self.payer_note_truncated.as_ref().map(|s| WithoutLength(&s.0)), option),
1149                 });
1150                 Ok(())
1151         }
1152 }
1153
1154 impl Readable for InvoiceRequestFields {
1155         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
1156                 _init_and_read_len_prefixed_tlv_fields!(reader, {
1157                         (0, payer_id, required),
1158                         (2, features, (option, encoding: (InvoiceRequestFeatures, WithoutLength))),
1159                         (4, quantity, (option, encoding: (u64, HighZeroBytesDroppedBigSize))),
1160                         (6, payer_note_truncated, (option, encoding: (String, WithoutLength))),
1161                 });
1162                 let features = features.unwrap_or(InvoiceRequestFeatures::empty());
1163
1164                 Ok(InvoiceRequestFields {
1165                         payer_id: payer_id.0.unwrap(), features, quantity,
1166                         payer_note_truncated: payer_note_truncated.map(|s| UntrustedString(s)),
1167                 })
1168         }
1169 }
1170
1171 #[cfg(test)]
1172 mod tests {
1173         use super::{InvoiceRequest, InvoiceRequestFields, InvoiceRequestTlvStreamRef, PAYER_NOTE_LIMIT, SIGNATURE_TAG, UnsignedInvoiceRequest};
1174
1175         use bitcoin::blockdata::constants::ChainHash;
1176         use bitcoin::network::constants::Network;
1177         use bitcoin::secp256k1::{KeyPair, Secp256k1, SecretKey, self};
1178         use core::num::NonZeroU64;
1179         #[cfg(feature = "std")]
1180         use core::time::Duration;
1181         use crate::sign::KeyMaterial;
1182         use crate::ln::channelmanager::PaymentId;
1183         use crate::ln::features::{InvoiceRequestFeatures, OfferFeatures};
1184         use crate::ln::inbound_payment::ExpandedKey;
1185         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
1186         use crate::offers::invoice::{Bolt12Invoice, SIGNATURE_TAG as INVOICE_SIGNATURE_TAG};
1187         use crate::offers::merkle::{SignError, SignatureTlvStreamRef, TaggedHash, self};
1188         use crate::offers::offer::{Amount, OfferTlvStreamRef, Quantity};
1189         #[cfg(not(c_bindings))]
1190         use {
1191                 crate::offers::offer::OfferBuilder,
1192         };
1193         #[cfg(c_bindings)]
1194         use {
1195                 crate::offers::offer::OfferWithExplicitMetadataBuilder as OfferBuilder,
1196         };
1197         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
1198         use crate::offers::payer::PayerTlvStreamRef;
1199         use crate::offers::test_utils::*;
1200         use crate::util::ser::{BigSize, Readable, Writeable};
1201         use crate::util::string::{PrintableString, UntrustedString};
1202
1203         #[test]
1204         fn builds_invoice_request_with_defaults() {
1205                 let unsigned_invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1206                         .amount_msats(1000)
1207                         .build().unwrap()
1208                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1209                         .build().unwrap();
1210                 #[cfg(c_bindings)]
1211                 let mut unsigned_invoice_request = unsigned_invoice_request;
1212
1213                 let mut buffer = Vec::new();
1214                 unsigned_invoice_request.write(&mut buffer).unwrap();
1215
1216                 assert_eq!(unsigned_invoice_request.bytes, buffer.as_slice());
1217                 assert_eq!(unsigned_invoice_request.payer_metadata(), &[1; 32]);
1218                 assert_eq!(unsigned_invoice_request.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
1219                 assert_eq!(unsigned_invoice_request.metadata(), None);
1220                 assert_eq!(unsigned_invoice_request.amount(), Some(&Amount::Bitcoin { amount_msats: 1000 }));
1221                 assert_eq!(unsigned_invoice_request.description(), PrintableString("foo"));
1222                 assert_eq!(unsigned_invoice_request.offer_features(), &OfferFeatures::empty());
1223                 assert_eq!(unsigned_invoice_request.absolute_expiry(), None);
1224                 assert_eq!(unsigned_invoice_request.paths(), &[]);
1225                 assert_eq!(unsigned_invoice_request.issuer(), None);
1226                 assert_eq!(unsigned_invoice_request.supported_quantity(), Quantity::One);
1227                 assert_eq!(unsigned_invoice_request.signing_pubkey(), recipient_pubkey());
1228                 assert_eq!(unsigned_invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
1229                 assert_eq!(unsigned_invoice_request.amount_msats(), None);
1230                 assert_eq!(unsigned_invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
1231                 assert_eq!(unsigned_invoice_request.quantity(), None);
1232                 assert_eq!(unsigned_invoice_request.payer_id(), payer_pubkey());
1233                 assert_eq!(unsigned_invoice_request.payer_note(), None);
1234
1235                 match UnsignedInvoiceRequest::try_from(buffer) {
1236                         Err(e) => panic!("error parsing unsigned invoice request: {:?}", e),
1237                         Ok(parsed) => {
1238                                 assert_eq!(parsed.bytes, unsigned_invoice_request.bytes);
1239                                 assert_eq!(parsed.tagged_hash, unsigned_invoice_request.tagged_hash);
1240                         },
1241                 }
1242
1243                 let invoice_request = unsigned_invoice_request.sign(payer_sign).unwrap();
1244
1245                 let mut buffer = Vec::new();
1246                 invoice_request.write(&mut buffer).unwrap();
1247
1248                 assert_eq!(invoice_request.bytes, buffer.as_slice());
1249                 assert_eq!(invoice_request.payer_metadata(), &[1; 32]);
1250                 assert_eq!(invoice_request.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
1251                 assert_eq!(invoice_request.metadata(), None);
1252                 assert_eq!(invoice_request.amount(), Some(&Amount::Bitcoin { amount_msats: 1000 }));
1253                 assert_eq!(invoice_request.description(), PrintableString("foo"));
1254                 assert_eq!(invoice_request.offer_features(), &OfferFeatures::empty());
1255                 assert_eq!(invoice_request.absolute_expiry(), None);
1256                 assert_eq!(invoice_request.paths(), &[]);
1257                 assert_eq!(invoice_request.issuer(), None);
1258                 assert_eq!(invoice_request.supported_quantity(), Quantity::One);
1259                 assert_eq!(invoice_request.signing_pubkey(), recipient_pubkey());
1260                 assert_eq!(invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
1261                 assert_eq!(invoice_request.amount_msats(), None);
1262                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
1263                 assert_eq!(invoice_request.quantity(), None);
1264                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
1265                 assert_eq!(invoice_request.payer_note(), None);
1266
1267                 let message = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &invoice_request.bytes);
1268                 assert!(merkle::verify_signature(&invoice_request.signature, &message, payer_pubkey()).is_ok());
1269
1270                 assert_eq!(
1271                         invoice_request.as_tlv_stream(),
1272                         (
1273                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
1274                                 OfferTlvStreamRef {
1275                                         chains: None,
1276                                         metadata: None,
1277                                         currency: None,
1278                                         amount: Some(1000),
1279                                         description: Some(&String::from("foo")),
1280                                         features: None,
1281                                         absolute_expiry: None,
1282                                         paths: None,
1283                                         issuer: None,
1284                                         quantity_max: None,
1285                                         node_id: Some(&recipient_pubkey()),
1286                                 },
1287                                 InvoiceRequestTlvStreamRef {
1288                                         chain: None,
1289                                         amount: None,
1290                                         features: None,
1291                                         quantity: None,
1292                                         payer_id: Some(&payer_pubkey()),
1293                                         payer_note: None,
1294                                 },
1295                                 SignatureTlvStreamRef { signature: Some(&invoice_request.signature()) },
1296                         ),
1297                 );
1298
1299                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1300                         panic!("error parsing invoice request: {:?}", e);
1301                 }
1302         }
1303
1304         #[cfg(feature = "std")]
1305         #[test]
1306         fn builds_invoice_request_from_offer_with_expiration() {
1307                 let future_expiry = Duration::from_secs(u64::max_value());
1308                 let past_expiry = Duration::from_secs(0);
1309
1310                 if let Err(e) = OfferBuilder::new("foo".into(), recipient_pubkey())
1311                         .amount_msats(1000)
1312                         .absolute_expiry(future_expiry)
1313                         .build().unwrap()
1314                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1315                         .build()
1316                 {
1317                         panic!("error building invoice_request: {:?}", e);
1318                 }
1319
1320                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1321                         .amount_msats(1000)
1322                         .absolute_expiry(past_expiry)
1323                         .build().unwrap()
1324                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1325                         .build()
1326                 {
1327                         Ok(_) => panic!("expected error"),
1328                         Err(e) => assert_eq!(e, Bolt12SemanticError::AlreadyExpired),
1329                 }
1330         }
1331
1332         #[test]
1333         fn builds_invoice_request_with_derived_metadata() {
1334                 let payer_id = payer_pubkey();
1335                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1336                 let entropy = FixedEntropy {};
1337                 let secp_ctx = Secp256k1::new();
1338                 let payment_id = PaymentId([1; 32]);
1339
1340                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1341                         .amount_msats(1000)
1342                         .build().unwrap();
1343                 let invoice_request = offer
1344                         .request_invoice_deriving_metadata(payer_id, &expanded_key, &entropy, payment_id)
1345                         .unwrap()
1346                         .build().unwrap()
1347                         .sign(payer_sign).unwrap();
1348                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
1349
1350                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
1351                         .unwrap()
1352                         .build().unwrap()
1353                         .sign(recipient_sign).unwrap();
1354                 match invoice.verify(&expanded_key, &secp_ctx) {
1355                         Ok(payment_id) => assert_eq!(payment_id, PaymentId([1; 32])),
1356                         Err(()) => panic!("verification failed"),
1357                 }
1358
1359                 // Fails verification with altered fields
1360                 let (
1361                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
1362                         mut invoice_tlv_stream, mut signature_tlv_stream
1363                 ) = invoice.as_tlv_stream();
1364                 invoice_request_tlv_stream.amount = Some(2000);
1365                 invoice_tlv_stream.amount = Some(2000);
1366
1367                 let tlv_stream =
1368                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1369                 let mut bytes = Vec::new();
1370                 tlv_stream.write(&mut bytes).unwrap();
1371
1372                 let message = TaggedHash::from_valid_tlv_stream_bytes(INVOICE_SIGNATURE_TAG, &bytes);
1373                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1374                 signature_tlv_stream.signature = Some(&signature);
1375
1376                 let mut encoded_invoice = bytes;
1377                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1378
1379                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1380                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1381
1382                 // Fails verification with altered metadata
1383                 let (
1384                         mut payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
1385                         mut signature_tlv_stream
1386                 ) = invoice.as_tlv_stream();
1387                 let metadata = payer_tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1388                 payer_tlv_stream.metadata = Some(&metadata);
1389
1390                 let tlv_stream =
1391                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1392                 let mut bytes = Vec::new();
1393                 tlv_stream.write(&mut bytes).unwrap();
1394
1395                 let message = TaggedHash::from_valid_tlv_stream_bytes(INVOICE_SIGNATURE_TAG, &bytes);
1396                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1397                 signature_tlv_stream.signature = Some(&signature);
1398
1399                 let mut encoded_invoice = bytes;
1400                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1401
1402                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1403                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1404         }
1405
1406         #[test]
1407         fn builds_invoice_request_with_derived_payer_id() {
1408                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1409                 let entropy = FixedEntropy {};
1410                 let secp_ctx = Secp256k1::new();
1411                 let payment_id = PaymentId([1; 32]);
1412
1413                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1414                         .amount_msats(1000)
1415                         .build().unwrap();
1416                 let invoice_request = offer
1417                         .request_invoice_deriving_payer_id(&expanded_key, &entropy, &secp_ctx, payment_id)
1418                         .unwrap()
1419                         .build_and_sign()
1420                         .unwrap();
1421
1422                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
1423                         .unwrap()
1424                         .build().unwrap()
1425                         .sign(recipient_sign).unwrap();
1426                 match invoice.verify(&expanded_key, &secp_ctx) {
1427                         Ok(payment_id) => assert_eq!(payment_id, PaymentId([1; 32])),
1428                         Err(()) => panic!("verification failed"),
1429                 }
1430
1431                 // Fails verification with altered fields
1432                 let (
1433                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
1434                         mut invoice_tlv_stream, mut signature_tlv_stream
1435                 ) = invoice.as_tlv_stream();
1436                 invoice_request_tlv_stream.amount = Some(2000);
1437                 invoice_tlv_stream.amount = Some(2000);
1438
1439                 let tlv_stream =
1440                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1441                 let mut bytes = Vec::new();
1442                 tlv_stream.write(&mut bytes).unwrap();
1443
1444                 let message = TaggedHash::from_valid_tlv_stream_bytes(INVOICE_SIGNATURE_TAG, &bytes);
1445                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1446                 signature_tlv_stream.signature = Some(&signature);
1447
1448                 let mut encoded_invoice = bytes;
1449                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1450
1451                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1452                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1453
1454                 // Fails verification with altered payer id
1455                 let (
1456                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream, invoice_tlv_stream,
1457                         mut signature_tlv_stream
1458                 ) = invoice.as_tlv_stream();
1459                 let payer_id = pubkey(1);
1460                 invoice_request_tlv_stream.payer_id = Some(&payer_id);
1461
1462                 let tlv_stream =
1463                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1464                 let mut bytes = Vec::new();
1465                 tlv_stream.write(&mut bytes).unwrap();
1466
1467                 let message = TaggedHash::from_valid_tlv_stream_bytes(INVOICE_SIGNATURE_TAG, &bytes);
1468                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1469                 signature_tlv_stream.signature = Some(&signature);
1470
1471                 let mut encoded_invoice = bytes;
1472                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1473
1474                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1475                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1476         }
1477
1478         #[test]
1479         fn builds_invoice_request_with_chain() {
1480                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
1481                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
1482
1483                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1484                         .amount_msats(1000)
1485                         .build().unwrap()
1486                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1487                         .chain(Network::Bitcoin).unwrap()
1488                         .build().unwrap()
1489                         .sign(payer_sign).unwrap();
1490                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1491                 assert_eq!(invoice_request.chain(), mainnet);
1492                 assert_eq!(tlv_stream.chain, None);
1493
1494                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1495                         .amount_msats(1000)
1496                         .chain(Network::Testnet)
1497                         .build().unwrap()
1498                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1499                         .chain(Network::Testnet).unwrap()
1500                         .build().unwrap()
1501                         .sign(payer_sign).unwrap();
1502                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1503                 assert_eq!(invoice_request.chain(), testnet);
1504                 assert_eq!(tlv_stream.chain, Some(&testnet));
1505
1506                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1507                         .amount_msats(1000)
1508                         .chain(Network::Bitcoin)
1509                         .chain(Network::Testnet)
1510                         .build().unwrap()
1511                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1512                         .chain(Network::Bitcoin).unwrap()
1513                         .build().unwrap()
1514                         .sign(payer_sign).unwrap();
1515                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1516                 assert_eq!(invoice_request.chain(), mainnet);
1517                 assert_eq!(tlv_stream.chain, None);
1518
1519                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1520                         .amount_msats(1000)
1521                         .chain(Network::Bitcoin)
1522                         .chain(Network::Testnet)
1523                         .build().unwrap()
1524                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1525                         .chain(Network::Bitcoin).unwrap()
1526                         .chain(Network::Testnet).unwrap()
1527                         .build().unwrap()
1528                         .sign(payer_sign).unwrap();
1529                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1530                 assert_eq!(invoice_request.chain(), testnet);
1531                 assert_eq!(tlv_stream.chain, Some(&testnet));
1532
1533                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1534                         .amount_msats(1000)
1535                         .chain(Network::Testnet)
1536                         .build().unwrap()
1537                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1538                         .chain(Network::Bitcoin)
1539                 {
1540                         Ok(_) => panic!("expected error"),
1541                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
1542                 }
1543
1544                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1545                         .amount_msats(1000)
1546                         .chain(Network::Testnet)
1547                         .build().unwrap()
1548                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1549                         .build()
1550                 {
1551                         Ok(_) => panic!("expected error"),
1552                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
1553                 }
1554         }
1555
1556         #[test]
1557         fn builds_invoice_request_with_amount() {
1558                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1559                         .amount_msats(1000)
1560                         .build().unwrap()
1561                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1562                         .amount_msats(1000).unwrap()
1563                         .build().unwrap()
1564                         .sign(payer_sign).unwrap();
1565                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1566                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1567                 assert_eq!(tlv_stream.amount, Some(1000));
1568
1569                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1570                         .amount_msats(1000)
1571                         .build().unwrap()
1572                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1573                         .amount_msats(1001).unwrap()
1574                         .amount_msats(1000).unwrap()
1575                         .build().unwrap()
1576                         .sign(payer_sign).unwrap();
1577                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1578                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1579                 assert_eq!(tlv_stream.amount, Some(1000));
1580
1581                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1582                         .amount_msats(1000)
1583                         .build().unwrap()
1584                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1585                         .amount_msats(1001).unwrap()
1586                         .build().unwrap()
1587                         .sign(payer_sign).unwrap();
1588                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1589                 assert_eq!(invoice_request.amount_msats(), Some(1001));
1590                 assert_eq!(tlv_stream.amount, Some(1001));
1591
1592                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1593                         .amount_msats(1000)
1594                         .build().unwrap()
1595                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1596                         .amount_msats(999)
1597                 {
1598                         Ok(_) => panic!("expected error"),
1599                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1600                 }
1601
1602                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1603                         .amount_msats(1000)
1604                         .supported_quantity(Quantity::Unbounded)
1605                         .build().unwrap()
1606                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1607                         .quantity(2).unwrap()
1608                         .amount_msats(1000)
1609                 {
1610                         Ok(_) => panic!("expected error"),
1611                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1612                 }
1613
1614                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1615                         .amount_msats(1000)
1616                         .build().unwrap()
1617                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1618                         .amount_msats(MAX_VALUE_MSAT + 1)
1619                 {
1620                         Ok(_) => panic!("expected error"),
1621                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1622                 }
1623
1624                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1625                         .amount_msats(1000)
1626                         .supported_quantity(Quantity::Unbounded)
1627                         .build().unwrap()
1628                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1629                         .amount_msats(1000).unwrap()
1630                         .quantity(2).unwrap()
1631                         .build()
1632                 {
1633                         Ok(_) => panic!("expected error"),
1634                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1635                 }
1636
1637                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1638                         .build().unwrap()
1639                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1640                         .build()
1641                 {
1642                         Ok(_) => panic!("expected error"),
1643                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingAmount),
1644                 }
1645
1646                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1647                         .amount_msats(1000)
1648                         .supported_quantity(Quantity::Unbounded)
1649                         .build().unwrap()
1650                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1651                         .quantity(u64::max_value()).unwrap()
1652                         .build()
1653                 {
1654                         Ok(_) => panic!("expected error"),
1655                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1656                 }
1657         }
1658
1659         #[test]
1660         fn builds_invoice_request_with_features() {
1661                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1662                         .amount_msats(1000)
1663                         .build().unwrap()
1664                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1665                         .features_unchecked(InvoiceRequestFeatures::unknown())
1666                         .build().unwrap()
1667                         .sign(payer_sign).unwrap();
1668                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1669                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::unknown());
1670                 assert_eq!(tlv_stream.features, Some(&InvoiceRequestFeatures::unknown()));
1671
1672                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1673                         .amount_msats(1000)
1674                         .build().unwrap()
1675                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1676                         .features_unchecked(InvoiceRequestFeatures::unknown())
1677                         .features_unchecked(InvoiceRequestFeatures::empty())
1678                         .build().unwrap()
1679                         .sign(payer_sign).unwrap();
1680                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1681                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
1682                 assert_eq!(tlv_stream.features, None);
1683         }
1684
1685         #[test]
1686         fn builds_invoice_request_with_quantity() {
1687                 let one = NonZeroU64::new(1).unwrap();
1688                 let ten = NonZeroU64::new(10).unwrap();
1689
1690                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1691                         .amount_msats(1000)
1692                         .supported_quantity(Quantity::One)
1693                         .build().unwrap()
1694                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1695                         .build().unwrap()
1696                         .sign(payer_sign).unwrap();
1697                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1698                 assert_eq!(invoice_request.quantity(), None);
1699                 assert_eq!(tlv_stream.quantity, None);
1700
1701                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1702                         .amount_msats(1000)
1703                         .supported_quantity(Quantity::One)
1704                         .build().unwrap()
1705                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1706                         .amount_msats(2_000).unwrap()
1707                         .quantity(2)
1708                 {
1709                         Ok(_) => panic!("expected error"),
1710                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnexpectedQuantity),
1711                 }
1712
1713                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1714                         .amount_msats(1000)
1715                         .supported_quantity(Quantity::Bounded(ten))
1716                         .build().unwrap()
1717                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1718                         .amount_msats(10_000).unwrap()
1719                         .quantity(10).unwrap()
1720                         .build().unwrap()
1721                         .sign(payer_sign).unwrap();
1722                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1723                 assert_eq!(invoice_request.amount_msats(), Some(10_000));
1724                 assert_eq!(tlv_stream.amount, Some(10_000));
1725
1726                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1727                         .amount_msats(1000)
1728                         .supported_quantity(Quantity::Bounded(ten))
1729                         .build().unwrap()
1730                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1731                         .amount_msats(11_000).unwrap()
1732                         .quantity(11)
1733                 {
1734                         Ok(_) => panic!("expected error"),
1735                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidQuantity),
1736                 }
1737
1738                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1739                         .amount_msats(1000)
1740                         .supported_quantity(Quantity::Unbounded)
1741                         .build().unwrap()
1742                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1743                         .amount_msats(2_000).unwrap()
1744                         .quantity(2).unwrap()
1745                         .build().unwrap()
1746                         .sign(payer_sign).unwrap();
1747                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1748                 assert_eq!(invoice_request.amount_msats(), Some(2_000));
1749                 assert_eq!(tlv_stream.amount, Some(2_000));
1750
1751                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1752                         .amount_msats(1000)
1753                         .supported_quantity(Quantity::Unbounded)
1754                         .build().unwrap()
1755                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1756                         .build()
1757                 {
1758                         Ok(_) => panic!("expected error"),
1759                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
1760                 }
1761
1762                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1763                         .amount_msats(1000)
1764                         .supported_quantity(Quantity::Bounded(one))
1765                         .build().unwrap()
1766                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1767                         .build()
1768                 {
1769                         Ok(_) => panic!("expected error"),
1770                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
1771                 }
1772         }
1773
1774         #[test]
1775         fn builds_invoice_request_with_payer_note() {
1776                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1777                         .amount_msats(1000)
1778                         .build().unwrap()
1779                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1780                         .payer_note("bar".into())
1781                         .build().unwrap()
1782                         .sign(payer_sign).unwrap();
1783                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1784                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("bar")));
1785                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
1786
1787                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1788                         .amount_msats(1000)
1789                         .build().unwrap()
1790                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1791                         .payer_note("bar".into())
1792                         .payer_note("baz".into())
1793                         .build().unwrap()
1794                         .sign(payer_sign).unwrap();
1795                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1796                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("baz")));
1797                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
1798         }
1799
1800         #[test]
1801         fn fails_signing_invoice_request() {
1802                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1803                         .amount_msats(1000)
1804                         .build().unwrap()
1805                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1806                         .build().unwrap()
1807                         .sign(fail_sign)
1808                 {
1809                         Ok(_) => panic!("expected error"),
1810                         Err(e) => assert_eq!(e, SignError::Signing),
1811                 }
1812
1813                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1814                         .amount_msats(1000)
1815                         .build().unwrap()
1816                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1817                         .build().unwrap()
1818                         .sign(recipient_sign)
1819                 {
1820                         Ok(_) => panic!("expected error"),
1821                         Err(e) => assert_eq!(e, SignError::Verification(secp256k1::Error::InvalidSignature)),
1822                 }
1823         }
1824
1825         #[test]
1826         fn fails_responding_with_unknown_required_features() {
1827                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1828                         .amount_msats(1000)
1829                         .build().unwrap()
1830                         .request_invoice(vec![42; 32], payer_pubkey()).unwrap()
1831                         .features_unchecked(InvoiceRequestFeatures::unknown())
1832                         .build().unwrap()
1833                         .sign(payer_sign).unwrap()
1834                         .respond_with_no_std(payment_paths(), payment_hash(), now())
1835                 {
1836                         Ok(_) => panic!("expected error"),
1837                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1838                 }
1839         }
1840
1841         #[test]
1842         fn parses_invoice_request_with_metadata() {
1843                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1844                         .amount_msats(1000)
1845                         .build().unwrap()
1846                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1847                         .build().unwrap()
1848                         .sign(payer_sign).unwrap();
1849
1850                 let mut buffer = Vec::new();
1851                 invoice_request.write(&mut buffer).unwrap();
1852
1853                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1854                         panic!("error parsing invoice_request: {:?}", e);
1855                 }
1856         }
1857
1858         #[test]
1859         fn parses_invoice_request_with_chain() {
1860                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1861                         .amount_msats(1000)
1862                         .build().unwrap()
1863                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1864                         .chain(Network::Bitcoin).unwrap()
1865                         .build().unwrap()
1866                         .sign(payer_sign).unwrap();
1867
1868                 let mut buffer = Vec::new();
1869                 invoice_request.write(&mut buffer).unwrap();
1870
1871                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1872                         panic!("error parsing invoice_request: {:?}", e);
1873                 }
1874
1875                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1876                         .amount_msats(1000)
1877                         .build().unwrap()
1878                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1879                         .chain_unchecked(Network::Testnet)
1880                         .build_unchecked()
1881                         .sign(payer_sign).unwrap();
1882
1883                 let mut buffer = Vec::new();
1884                 invoice_request.write(&mut buffer).unwrap();
1885
1886                 match InvoiceRequest::try_from(buffer) {
1887                         Ok(_) => panic!("expected error"),
1888                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnsupportedChain)),
1889                 }
1890         }
1891
1892         #[test]
1893         fn parses_invoice_request_with_amount() {
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                         .build().unwrap()
1899                         .sign(payer_sign).unwrap();
1900
1901                 let mut buffer = Vec::new();
1902                 invoice_request.write(&mut buffer).unwrap();
1903
1904                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1905                         panic!("error parsing invoice_request: {:?}", e);
1906                 }
1907
1908                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1909                         .build().unwrap()
1910                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1911                         .amount_msats(1000).unwrap()
1912                         .build().unwrap()
1913                         .sign(payer_sign).unwrap();
1914
1915                 let mut buffer = Vec::new();
1916                 invoice_request.write(&mut buffer).unwrap();
1917
1918                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1919                         panic!("error parsing invoice_request: {:?}", e);
1920                 }
1921
1922                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1923                         .build().unwrap()
1924                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1925                         .build_unchecked()
1926                         .sign(payer_sign).unwrap();
1927
1928                 let mut buffer = Vec::new();
1929                 invoice_request.write(&mut buffer).unwrap();
1930
1931                 match InvoiceRequest::try_from(buffer) {
1932                         Ok(_) => panic!("expected error"),
1933                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1934                 }
1935
1936                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1937                         .amount_msats(1000)
1938                         .build().unwrap()
1939                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1940                         .amount_msats_unchecked(999)
1941                         .build_unchecked()
1942                         .sign(payer_sign).unwrap();
1943
1944                 let mut buffer = Vec::new();
1945                 invoice_request.write(&mut buffer).unwrap();
1946
1947                 match InvoiceRequest::try_from(buffer) {
1948                         Ok(_) => panic!("expected error"),
1949                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InsufficientAmount)),
1950                 }
1951
1952                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1953                         .amount(Amount::Currency { iso4217_code: *b"USD", amount: 1000 })
1954                         .build_unchecked()
1955                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1956                         .build_unchecked()
1957                         .sign(payer_sign).unwrap();
1958
1959                 let mut buffer = Vec::new();
1960                 invoice_request.write(&mut buffer).unwrap();
1961
1962                 match InvoiceRequest::try_from(buffer) {
1963                         Ok(_) => panic!("expected error"),
1964                         Err(e) => {
1965                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnsupportedCurrency));
1966                         },
1967                 }
1968
1969                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1970                         .amount_msats(1000)
1971                         .supported_quantity(Quantity::Unbounded)
1972                         .build().unwrap()
1973                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1974                         .quantity(u64::max_value()).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) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1984                 }
1985         }
1986
1987         #[test]
1988         fn parses_invoice_request_with_quantity() {
1989                 let one = NonZeroU64::new(1).unwrap();
1990                 let ten = NonZeroU64::new(10).unwrap();
1991
1992                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1993                         .amount_msats(1000)
1994                         .supported_quantity(Quantity::One)
1995                         .build().unwrap()
1996                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1997                         .build().unwrap()
1998                         .sign(payer_sign).unwrap();
1999
2000                 let mut buffer = Vec::new();
2001                 invoice_request.write(&mut buffer).unwrap();
2002
2003                 if let Err(e) = InvoiceRequest::try_from(buffer) {
2004                         panic!("error parsing invoice_request: {:?}", e);
2005                 }
2006
2007                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2008                         .amount_msats(1000)
2009                         .supported_quantity(Quantity::One)
2010                         .build().unwrap()
2011                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2012                         .amount_msats(2_000).unwrap()
2013                         .quantity_unchecked(2)
2014                         .build_unchecked()
2015                         .sign(payer_sign).unwrap();
2016
2017                 let mut buffer = Vec::new();
2018                 invoice_request.write(&mut buffer).unwrap();
2019
2020                 match InvoiceRequest::try_from(buffer) {
2021                         Ok(_) => panic!("expected error"),
2022                         Err(e) => {
2023                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnexpectedQuantity));
2024                         },
2025                 }
2026
2027                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2028                         .amount_msats(1000)
2029                         .supported_quantity(Quantity::Bounded(ten))
2030                         .build().unwrap()
2031                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2032                         .amount_msats(10_000).unwrap()
2033                         .quantity(10).unwrap()
2034                         .build().unwrap()
2035                         .sign(payer_sign).unwrap();
2036
2037                 let mut buffer = Vec::new();
2038                 invoice_request.write(&mut buffer).unwrap();
2039
2040                 if let Err(e) = InvoiceRequest::try_from(buffer) {
2041                         panic!("error parsing invoice_request: {:?}", e);
2042                 }
2043
2044                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2045                         .amount_msats(1000)
2046                         .supported_quantity(Quantity::Bounded(ten))
2047                         .build().unwrap()
2048                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2049                         .amount_msats(11_000).unwrap()
2050                         .quantity_unchecked(11)
2051                         .build_unchecked()
2052                         .sign(payer_sign).unwrap();
2053
2054                 let mut buffer = Vec::new();
2055                 invoice_request.write(&mut buffer).unwrap();
2056
2057                 match InvoiceRequest::try_from(buffer) {
2058                         Ok(_) => panic!("expected error"),
2059                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidQuantity)),
2060                 }
2061
2062                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2063                         .amount_msats(1000)
2064                         .supported_quantity(Quantity::Unbounded)
2065                         .build().unwrap()
2066                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2067                         .amount_msats(2_000).unwrap()
2068                         .quantity(2).unwrap()
2069                         .build().unwrap()
2070                         .sign(payer_sign).unwrap();
2071
2072                 let mut buffer = Vec::new();
2073                 invoice_request.write(&mut buffer).unwrap();
2074
2075                 if let Err(e) = InvoiceRequest::try_from(buffer) {
2076                         panic!("error parsing invoice_request: {:?}", e);
2077                 }
2078
2079                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2080                         .amount_msats(1000)
2081                         .supported_quantity(Quantity::Unbounded)
2082                         .build().unwrap()
2083                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2084                         .build_unchecked()
2085                         .sign(payer_sign).unwrap();
2086
2087                 let mut buffer = Vec::new();
2088                 invoice_request.write(&mut buffer).unwrap();
2089
2090                 match InvoiceRequest::try_from(buffer) {
2091                         Ok(_) => panic!("expected error"),
2092                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
2093                 }
2094
2095                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2096                         .amount_msats(1000)
2097                         .supported_quantity(Quantity::Bounded(one))
2098                         .build().unwrap()
2099                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2100                         .build_unchecked()
2101                         .sign(payer_sign).unwrap();
2102
2103                 let mut buffer = Vec::new();
2104                 invoice_request.write(&mut buffer).unwrap();
2105
2106                 match InvoiceRequest::try_from(buffer) {
2107                         Ok(_) => panic!("expected error"),
2108                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
2109                 }
2110         }
2111
2112         #[test]
2113         fn fails_parsing_invoice_request_without_metadata() {
2114                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
2115                         .amount_msats(1000)
2116                         .build().unwrap();
2117                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2118                         .build().unwrap();
2119                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
2120                 tlv_stream.0.metadata = None;
2121
2122                 let mut buffer = Vec::new();
2123                 tlv_stream.write(&mut buffer).unwrap();
2124
2125                 match InvoiceRequest::try_from(buffer) {
2126                         Ok(_) => panic!("expected error"),
2127                         Err(e) => {
2128                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPayerMetadata));
2129                         },
2130                 }
2131         }
2132
2133         #[test]
2134         fn fails_parsing_invoice_request_without_payer_id() {
2135                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
2136                         .amount_msats(1000)
2137                         .build().unwrap();
2138                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2139                         .build().unwrap();
2140                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
2141                 tlv_stream.2.payer_id = None;
2142
2143                 let mut buffer = Vec::new();
2144                 tlv_stream.write(&mut buffer).unwrap();
2145
2146                 match InvoiceRequest::try_from(buffer) {
2147                         Ok(_) => panic!("expected error"),
2148                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPayerId)),
2149                 }
2150         }
2151
2152         #[test]
2153         fn fails_parsing_invoice_request_without_node_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.1.node_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) => {
2168                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
2169                         },
2170                 }
2171         }
2172
2173         #[test]
2174         fn fails_parsing_invoice_request_without_signature() {
2175                 let mut buffer = Vec::new();
2176                 OfferBuilder::new("foo".into(), recipient_pubkey())
2177                         .amount_msats(1000)
2178                         .build().unwrap()
2179                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2180                         .build().unwrap()
2181                         .contents
2182                         .write(&mut buffer).unwrap();
2183
2184                 match InvoiceRequest::try_from(buffer) {
2185                         Ok(_) => panic!("expected error"),
2186                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
2187                 }
2188         }
2189
2190         #[test]
2191         fn fails_parsing_invoice_request_with_invalid_signature() {
2192                 let mut invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2193                         .amount_msats(1000)
2194                         .build().unwrap()
2195                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2196                         .build().unwrap()
2197                         .sign(payer_sign).unwrap();
2198                 let last_signature_byte = invoice_request.bytes.last_mut().unwrap();
2199                 *last_signature_byte = last_signature_byte.wrapping_add(1);
2200
2201                 let mut buffer = Vec::new();
2202                 invoice_request.write(&mut buffer).unwrap();
2203
2204                 match InvoiceRequest::try_from(buffer) {
2205                         Ok(_) => panic!("expected error"),
2206                         Err(e) => {
2207                                 assert_eq!(e, Bolt12ParseError::InvalidSignature(secp256k1::Error::InvalidSignature));
2208                         },
2209                 }
2210         }
2211
2212         #[test]
2213         fn fails_parsing_invoice_request_with_extra_tlv_records() {
2214                 let secp_ctx = Secp256k1::new();
2215                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2216                 let invoice_request = OfferBuilder::new("foo".into(), keys.public_key())
2217                         .amount_msats(1000)
2218                         .build().unwrap()
2219                         .request_invoice(vec![1; 32], keys.public_key()).unwrap()
2220                         .build().unwrap()
2221                         .sign(|message: &UnsignedInvoiceRequest|
2222                                 Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
2223                         )
2224                         .unwrap();
2225
2226                 let mut encoded_invoice_request = Vec::new();
2227                 invoice_request.write(&mut encoded_invoice_request).unwrap();
2228                 BigSize(1002).write(&mut encoded_invoice_request).unwrap();
2229                 BigSize(32).write(&mut encoded_invoice_request).unwrap();
2230                 [42u8; 32].write(&mut encoded_invoice_request).unwrap();
2231
2232                 match InvoiceRequest::try_from(encoded_invoice_request) {
2233                         Ok(_) => panic!("expected error"),
2234                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
2235                 }
2236         }
2237
2238         #[test]
2239         fn copies_verified_invoice_request_fields() {
2240                 let desc = "foo".to_string();
2241                 let node_id = recipient_pubkey();
2242                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
2243                 let entropy = FixedEntropy {};
2244                 let secp_ctx = Secp256k1::new();
2245
2246                 #[cfg(c_bindings)]
2247                 use crate::offers::offer::OfferWithDerivedMetadataBuilder as OfferBuilder;
2248                 let offer = OfferBuilder
2249                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
2250                         .chain(Network::Testnet)
2251                         .amount_msats(1000)
2252                         .supported_quantity(Quantity::Unbounded)
2253                         .build().unwrap();
2254                 assert_eq!(offer.signing_pubkey(), node_id);
2255
2256                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2257                         .chain(Network::Testnet).unwrap()
2258                         .quantity(1).unwrap()
2259                         .payer_note("0".repeat(PAYER_NOTE_LIMIT * 2))
2260                         .build().unwrap()
2261                         .sign(payer_sign).unwrap();
2262                 match invoice_request.verify(&expanded_key, &secp_ctx) {
2263                         Ok(invoice_request) => {
2264                                 let fields = invoice_request.fields();
2265                                 assert_eq!(invoice_request.offer_id, offer.id());
2266                                 assert_eq!(
2267                                         fields,
2268                                         InvoiceRequestFields {
2269                                                 payer_id: payer_pubkey(),
2270                                                 features: InvoiceRequestFeatures::empty(),
2271                                                 quantity: Some(1),
2272                                                 payer_note_truncated: Some(UntrustedString("0".repeat(PAYER_NOTE_LIMIT))),
2273                                         }
2274                                 );
2275
2276                                 let mut buffer = Vec::new();
2277                                 fields.write(&mut buffer).unwrap();
2278
2279                                 let deserialized_fields: InvoiceRequestFields =
2280                                         Readable::read(&mut buffer.as_slice()).unwrap();
2281                                 assert_eq!(deserialized_fields, fields);
2282                         },
2283                         Err(_) => panic!("unexpected error"),
2284                 }
2285         }
2286 }