_ 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, SeekReadable, WithoutLength, Writeable, Writer};
  80 use crate::util::string::PrintableString;
  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
 877 impl InvoiceRequestContents {
 878         pub(super) fn metadata(&self) -> &[u8] {
 879                 self.inner.metadata()
 880         }
 881
 882         pub(super) fn derives_keys(&self) -> bool {
 883                 self.inner.payer.0.derives_payer_keys()
 884         }
 885
 886         pub(super) fn chain(&self) -> ChainHash {
 887                 self.inner.chain()
 888         }
 889
 890         pub(super) fn amount_msats(&self) -> Option<u64> {
 891                 self.inner.amount_msats
 892         }
 893
 894         pub(super) fn features(&self) -> &InvoiceRequestFeatures {
 895                 &self.inner.features
 896         }
 897
 898         pub(super) fn quantity(&self) -> Option<u64> {
 899                 self.inner.quantity
 900         }
 901
 902         pub(super) fn payer_id(&self) -> PublicKey {
 903                 self.payer_id
 904         }
 905
 906         pub(super) fn payer_note(&self) -> Option<PrintableString> {
 907                 self.inner.payer_note.as_ref()
 908                         .map(|payer_note| PrintableString(payer_note.as_str()))
 909         }
 910
 911         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 912                 let (payer, offer, mut invoice_request) = self.inner.as_tlv_stream();
 913                 invoice_request.payer_id = Some(&self.payer_id);
 914                 (payer, offer, invoice_request)
 915         }
 916 }
 917
 918 impl InvoiceRequestContentsWithoutPayerId {
 919         pub(super) fn metadata(&self) -> &[u8] {
 920                 self.payer.0.as_bytes().map(|bytes| bytes.as_slice()).unwrap_or(&[])
 921         }
 922
 923         pub(super) fn chain(&self) -> ChainHash {
 924                 self.chain.unwrap_or_else(|| self.offer.implied_chain())
 925         }
 926
 927         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 928                 let payer = PayerTlvStreamRef {
 929                         metadata: self.payer.0.as_bytes(),
 930                 };
 931
 932                 let offer = self.offer.as_tlv_stream();
 933
 934                 let features = {
 935                         if self.features == InvoiceRequestFeatures::empty() { None }
 936                         else { Some(&self.features) }
 937                 };
 938
 939                 let invoice_request = InvoiceRequestTlvStreamRef {
 940                         chain: self.chain.as_ref(),
 941                         amount: self.amount_msats,
 942                         features,
 943                         quantity: self.quantity,
 944                         payer_id: None,
 945                         payer_note: self.payer_note.as_ref(),
 946                 };
 947
 948                 (payer, offer, invoice_request)
 949         }
 950 }
 951
 952 impl Writeable for UnsignedInvoiceRequest {
 953         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 954                 WithoutLength(&self.bytes).write(writer)
 955         }
 956 }
 957
 958 impl Writeable for InvoiceRequest {
 959         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 960                 WithoutLength(&self.bytes).write(writer)
 961         }
 962 }
 963
 964 impl Writeable for InvoiceRequestContents {
 965         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 966                 self.as_tlv_stream().write(writer)
 967         }
 968 }
 969
 970 /// Valid type range for invoice_request TLV records.
 971 pub(super) const INVOICE_REQUEST_TYPES: core::ops::Range<u64> = 80..160;
 972
 973 /// TLV record type for [`InvoiceRequest::payer_id`] and [`Refund::payer_id`].
 974 ///
 975 /// [`Refund::payer_id`]: crate::offers::refund::Refund::payer_id
 976 pub(super) const INVOICE_REQUEST_PAYER_ID_TYPE: u64 = 88;
 977
 978 tlv_stream!(InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef, INVOICE_REQUEST_TYPES, {
 979         (80, chain: ChainHash),
 980         (82, amount: (u64, HighZeroBytesDroppedBigSize)),
 981         (84, features: (InvoiceRequestFeatures, WithoutLength)),
 982         (86, quantity: (u64, HighZeroBytesDroppedBigSize)),
 983         (INVOICE_REQUEST_PAYER_ID_TYPE, payer_id: PublicKey),
 984         (89, payer_note: (String, WithoutLength)),
 985 });
 986
 987 type FullInvoiceRequestTlvStream =
 988         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, SignatureTlvStream);
 989
 990 type FullInvoiceRequestTlvStreamRef<'a> = (
 991         PayerTlvStreamRef<'a>,
 992         OfferTlvStreamRef<'a>,
 993         InvoiceRequestTlvStreamRef<'a>,
 994         SignatureTlvStreamRef<'a>,
 995 );
 996
 997 impl SeekReadable for FullInvoiceRequestTlvStream {
 998         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 999                 let payer = SeekReadable::read(r)?;
1000                 let offer = SeekReadable::read(r)?;
1001                 let invoice_request = SeekReadable::read(r)?;
1002                 let signature = SeekReadable::read(r)?;
1003
1004                 Ok((payer, offer, invoice_request, signature))
1005         }
1006 }
1007
1008 type PartialInvoiceRequestTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
1009
1010 type PartialInvoiceRequestTlvStreamRef<'a> = (
1011         PayerTlvStreamRef<'a>,
1012         OfferTlvStreamRef<'a>,
1013         InvoiceRequestTlvStreamRef<'a>,
1014 );
1015
1016 impl TryFrom<Vec<u8>> for UnsignedInvoiceRequest {
1017         type Error = Bolt12ParseError;
1018
1019         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
1020                 let invoice_request = ParsedMessage::<PartialInvoiceRequestTlvStream>::try_from(bytes)?;
1021                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
1022                 let (
1023                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
1024                 ) = tlv_stream;
1025                 let contents = InvoiceRequestContents::try_from(
1026                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
1027                 )?;
1028
1029                 let tagged_hash = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &bytes);
1030
1031                 Ok(UnsignedInvoiceRequest { bytes, contents, tagged_hash })
1032         }
1033 }
1034
1035 impl TryFrom<Vec<u8>> for InvoiceRequest {
1036         type Error = Bolt12ParseError;
1037
1038         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
1039                 let invoice_request = ParsedMessage::<FullInvoiceRequestTlvStream>::try_from(bytes)?;
1040                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
1041                 let (
1042                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
1043                         SignatureTlvStream { signature },
1044                 ) = tlv_stream;
1045                 let contents = InvoiceRequestContents::try_from(
1046                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
1047                 )?;
1048
1049                 let signature = match signature {
1050                         None => return Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
1051                         Some(signature) => signature,
1052                 };
1053                 let message = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &bytes);
1054                 merkle::verify_signature(&signature, &message, contents.payer_id)?;
1055
1056                 Ok(InvoiceRequest { bytes, contents, signature })
1057         }
1058 }
1059
1060 impl TryFrom<PartialInvoiceRequestTlvStream> for InvoiceRequestContents {
1061         type Error = Bolt12SemanticError;
1062
1063         fn try_from(tlv_stream: PartialInvoiceRequestTlvStream) -> Result<Self, Self::Error> {
1064                 let (
1065                         PayerTlvStream { metadata },
1066                         offer_tlv_stream,
1067                         InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
1068                 ) = tlv_stream;
1069
1070                 let payer = match metadata {
1071                         None => return Err(Bolt12SemanticError::MissingPayerMetadata),
1072                         Some(metadata) => PayerContents(Metadata::Bytes(metadata)),
1073                 };
1074                 let offer = OfferContents::try_from(offer_tlv_stream)?;
1075
1076                 if !offer.supports_chain(chain.unwrap_or_else(|| offer.implied_chain())) {
1077                         return Err(Bolt12SemanticError::UnsupportedChain);
1078                 }
1079
1080                 if offer.amount().is_none() && amount.is_none() {
1081                         return Err(Bolt12SemanticError::MissingAmount);
1082                 }
1083
1084                 offer.check_quantity(quantity)?;
1085                 offer.check_amount_msats_for_quantity(amount, quantity)?;
1086
1087                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
1088
1089                 let payer_id = match payer_id {
1090                         None => return Err(Bolt12SemanticError::MissingPayerId),
1091                         Some(payer_id) => payer_id,
1092                 };
1093
1094                 Ok(InvoiceRequestContents {
1095                         inner: InvoiceRequestContentsWithoutPayerId {
1096                                 payer, offer, chain, amount_msats: amount, features, quantity, payer_note,
1097                         },
1098                         payer_id,
1099                 })
1100         }
1101 }
1102
1103 #[cfg(test)]
1104 mod tests {
1105         use super::{InvoiceRequest, InvoiceRequestTlvStreamRef, SIGNATURE_TAG, UnsignedInvoiceRequest};
1106
1107         use bitcoin::blockdata::constants::ChainHash;
1108         use bitcoin::network::constants::Network;
1109         use bitcoin::secp256k1::{KeyPair, Secp256k1, SecretKey, self};
1110         use core::num::NonZeroU64;
1111         #[cfg(feature = "std")]
1112         use core::time::Duration;
1113         use crate::sign::KeyMaterial;
1114         use crate::ln::channelmanager::PaymentId;
1115         use crate::ln::features::{InvoiceRequestFeatures, OfferFeatures};
1116         use crate::ln::inbound_payment::ExpandedKey;
1117         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
1118         use crate::offers::invoice::{Bolt12Invoice, SIGNATURE_TAG as INVOICE_SIGNATURE_TAG};
1119         use crate::offers::merkle::{SignError, SignatureTlvStreamRef, TaggedHash, self};
1120         use crate::offers::offer::{Amount, OfferTlvStreamRef, Quantity};
1121         #[cfg(not(c_bindings))]
1122         use {
1123                 crate::offers::offer::OfferBuilder,
1124         };
1125         #[cfg(c_bindings)]
1126         use {
1127                 crate::offers::offer::OfferWithExplicitMetadataBuilder as OfferBuilder,
1128         };
1129         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
1130         use crate::offers::payer::PayerTlvStreamRef;
1131         use crate::offers::test_utils::*;
1132         use crate::util::ser::{BigSize, Writeable};
1133         use crate::util::string::PrintableString;
1134
1135         #[test]
1136         fn builds_invoice_request_with_defaults() {
1137                 let unsigned_invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1138                         .amount_msats(1000)
1139                         .build().unwrap()
1140                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1141                         .build().unwrap();
1142                 #[cfg(c_bindings)]
1143                 let mut unsigned_invoice_request = unsigned_invoice_request;
1144
1145                 let mut buffer = Vec::new();
1146                 unsigned_invoice_request.write(&mut buffer).unwrap();
1147
1148                 assert_eq!(unsigned_invoice_request.bytes, buffer.as_slice());
1149                 assert_eq!(unsigned_invoice_request.payer_metadata(), &[1; 32]);
1150                 assert_eq!(unsigned_invoice_request.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
1151                 assert_eq!(unsigned_invoice_request.metadata(), None);
1152                 assert_eq!(unsigned_invoice_request.amount(), Some(&Amount::Bitcoin { amount_msats: 1000 }));
1153                 assert_eq!(unsigned_invoice_request.description(), PrintableString("foo"));
1154                 assert_eq!(unsigned_invoice_request.offer_features(), &OfferFeatures::empty());
1155                 assert_eq!(unsigned_invoice_request.absolute_expiry(), None);
1156                 assert_eq!(unsigned_invoice_request.paths(), &[]);
1157                 assert_eq!(unsigned_invoice_request.issuer(), None);
1158                 assert_eq!(unsigned_invoice_request.supported_quantity(), Quantity::One);
1159                 assert_eq!(unsigned_invoice_request.signing_pubkey(), recipient_pubkey());
1160                 assert_eq!(unsigned_invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
1161                 assert_eq!(unsigned_invoice_request.amount_msats(), None);
1162                 assert_eq!(unsigned_invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
1163                 assert_eq!(unsigned_invoice_request.quantity(), None);
1164                 assert_eq!(unsigned_invoice_request.payer_id(), payer_pubkey());
1165                 assert_eq!(unsigned_invoice_request.payer_note(), None);
1166
1167                 match UnsignedInvoiceRequest::try_from(buffer) {
1168                         Err(e) => panic!("error parsing unsigned invoice request: {:?}", e),
1169                         Ok(parsed) => {
1170                                 assert_eq!(parsed.bytes, unsigned_invoice_request.bytes);
1171                                 assert_eq!(parsed.tagged_hash, unsigned_invoice_request.tagged_hash);
1172                         },
1173                 }
1174
1175                 let invoice_request = unsigned_invoice_request.sign(payer_sign).unwrap();
1176
1177                 let mut buffer = Vec::new();
1178                 invoice_request.write(&mut buffer).unwrap();
1179
1180                 assert_eq!(invoice_request.bytes, buffer.as_slice());
1181                 assert_eq!(invoice_request.payer_metadata(), &[1; 32]);
1182                 assert_eq!(invoice_request.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
1183                 assert_eq!(invoice_request.metadata(), None);
1184                 assert_eq!(invoice_request.amount(), Some(&Amount::Bitcoin { amount_msats: 1000 }));
1185                 assert_eq!(invoice_request.description(), PrintableString("foo"));
1186                 assert_eq!(invoice_request.offer_features(), &OfferFeatures::empty());
1187                 assert_eq!(invoice_request.absolute_expiry(), None);
1188                 assert_eq!(invoice_request.paths(), &[]);
1189                 assert_eq!(invoice_request.issuer(), None);
1190                 assert_eq!(invoice_request.supported_quantity(), Quantity::One);
1191                 assert_eq!(invoice_request.signing_pubkey(), recipient_pubkey());
1192                 assert_eq!(invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
1193                 assert_eq!(invoice_request.amount_msats(), None);
1194                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
1195                 assert_eq!(invoice_request.quantity(), None);
1196                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
1197                 assert_eq!(invoice_request.payer_note(), None);
1198
1199                 let message = TaggedHash::from_valid_tlv_stream_bytes(SIGNATURE_TAG, &invoice_request.bytes);
1200                 assert!(merkle::verify_signature(&invoice_request.signature, &message, payer_pubkey()).is_ok());
1201
1202                 assert_eq!(
1203                         invoice_request.as_tlv_stream(),
1204                         (
1205                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
1206                                 OfferTlvStreamRef {
1207                                         chains: None,
1208                                         metadata: None,
1209                                         currency: None,
1210                                         amount: Some(1000),
1211                                         description: Some(&String::from("foo")),
1212                                         features: None,
1213                                         absolute_expiry: None,
1214                                         paths: None,
1215                                         issuer: None,
1216                                         quantity_max: None,
1217                                         node_id: Some(&recipient_pubkey()),
1218                                 },
1219                                 InvoiceRequestTlvStreamRef {
1220                                         chain: None,
1221                                         amount: None,
1222                                         features: None,
1223                                         quantity: None,
1224                                         payer_id: Some(&payer_pubkey()),
1225                                         payer_note: None,
1226                                 },
1227                                 SignatureTlvStreamRef { signature: Some(&invoice_request.signature()) },
1228                         ),
1229                 );
1230
1231                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1232                         panic!("error parsing invoice request: {:?}", e);
1233                 }
1234         }
1235
1236         #[cfg(feature = "std")]
1237         #[test]
1238         fn builds_invoice_request_from_offer_with_expiration() {
1239                 let future_expiry = Duration::from_secs(u64::max_value());
1240                 let past_expiry = Duration::from_secs(0);
1241
1242                 if let Err(e) = OfferBuilder::new("foo".into(), recipient_pubkey())
1243                         .amount_msats(1000)
1244                         .absolute_expiry(future_expiry)
1245                         .build().unwrap()
1246                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1247                         .build()
1248                 {
1249                         panic!("error building invoice_request: {:?}", e);
1250                 }
1251
1252                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1253                         .amount_msats(1000)
1254                         .absolute_expiry(past_expiry)
1255                         .build().unwrap()
1256                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1257                         .build()
1258                 {
1259                         Ok(_) => panic!("expected error"),
1260                         Err(e) => assert_eq!(e, Bolt12SemanticError::AlreadyExpired),
1261                 }
1262         }
1263
1264         #[test]
1265         fn builds_invoice_request_with_derived_metadata() {
1266                 let payer_id = payer_pubkey();
1267                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1268                 let entropy = FixedEntropy {};
1269                 let secp_ctx = Secp256k1::new();
1270                 let payment_id = PaymentId([1; 32]);
1271
1272                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1273                         .amount_msats(1000)
1274                         .build().unwrap();
1275                 let invoice_request = offer
1276                         .request_invoice_deriving_metadata(payer_id, &expanded_key, &entropy, payment_id)
1277                         .unwrap()
1278                         .build().unwrap()
1279                         .sign(payer_sign).unwrap();
1280                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
1281
1282                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
1283                         .unwrap()
1284                         .build().unwrap()
1285                         .sign(recipient_sign).unwrap();
1286                 match invoice.verify(&expanded_key, &secp_ctx) {
1287                         Ok(payment_id) => assert_eq!(payment_id, PaymentId([1; 32])),
1288                         Err(()) => panic!("verification failed"),
1289                 }
1290
1291                 // Fails verification with altered fields
1292                 let (
1293                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
1294                         mut invoice_tlv_stream, mut signature_tlv_stream
1295                 ) = invoice.as_tlv_stream();
1296                 invoice_request_tlv_stream.amount = Some(2000);
1297                 invoice_tlv_stream.amount = Some(2000);
1298
1299                 let tlv_stream =
1300                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1301                 let mut bytes = Vec::new();
1302                 tlv_stream.write(&mut bytes).unwrap();
1303
1304                 let message = TaggedHash::from_valid_tlv_stream_bytes(INVOICE_SIGNATURE_TAG, &bytes);
1305                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1306                 signature_tlv_stream.signature = Some(&signature);
1307
1308                 let mut encoded_invoice = bytes;
1309                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1310
1311                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1312                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1313
1314                 // Fails verification with altered metadata
1315                 let (
1316                         mut payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
1317                         mut signature_tlv_stream
1318                 ) = invoice.as_tlv_stream();
1319                 let metadata = payer_tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1320                 payer_tlv_stream.metadata = Some(&metadata);
1321
1322                 let tlv_stream =
1323                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1324                 let mut bytes = Vec::new();
1325                 tlv_stream.write(&mut bytes).unwrap();
1326
1327                 let message = TaggedHash::from_valid_tlv_stream_bytes(INVOICE_SIGNATURE_TAG, &bytes);
1328                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1329                 signature_tlv_stream.signature = Some(&signature);
1330
1331                 let mut encoded_invoice = bytes;
1332                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1333
1334                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1335                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1336         }
1337
1338         #[test]
1339         fn builds_invoice_request_with_derived_payer_id() {
1340                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1341                 let entropy = FixedEntropy {};
1342                 let secp_ctx = Secp256k1::new();
1343                 let payment_id = PaymentId([1; 32]);
1344
1345                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1346                         .amount_msats(1000)
1347                         .build().unwrap();
1348                 let invoice_request = offer
1349                         .request_invoice_deriving_payer_id(&expanded_key, &entropy, &secp_ctx, payment_id)
1350                         .unwrap()
1351                         .build_and_sign()
1352                         .unwrap();
1353
1354                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
1355                         .unwrap()
1356                         .build().unwrap()
1357                         .sign(recipient_sign).unwrap();
1358                 match invoice.verify(&expanded_key, &secp_ctx) {
1359                         Ok(payment_id) => assert_eq!(payment_id, PaymentId([1; 32])),
1360                         Err(()) => panic!("verification failed"),
1361                 }
1362
1363                 // Fails verification with altered fields
1364                 let (
1365                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
1366                         mut invoice_tlv_stream, mut signature_tlv_stream
1367                 ) = invoice.as_tlv_stream();
1368                 invoice_request_tlv_stream.amount = Some(2000);
1369                 invoice_tlv_stream.amount = Some(2000);
1370
1371                 let tlv_stream =
1372                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1373                 let mut bytes = Vec::new();
1374                 tlv_stream.write(&mut bytes).unwrap();
1375
1376                 let message = TaggedHash::from_valid_tlv_stream_bytes(INVOICE_SIGNATURE_TAG, &bytes);
1377                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1378                 signature_tlv_stream.signature = Some(&signature);
1379
1380                 let mut encoded_invoice = bytes;
1381                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1382
1383                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1384                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1385
1386                 // Fails verification with altered payer id
1387                 let (
1388                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream, invoice_tlv_stream,
1389                         mut signature_tlv_stream
1390                 ) = invoice.as_tlv_stream();
1391                 let payer_id = pubkey(1);
1392                 invoice_request_tlv_stream.payer_id = Some(&payer_id);
1393
1394                 let tlv_stream =
1395                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1396                 let mut bytes = Vec::new();
1397                 tlv_stream.write(&mut bytes).unwrap();
1398
1399                 let message = TaggedHash::from_valid_tlv_stream_bytes(INVOICE_SIGNATURE_TAG, &bytes);
1400                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1401                 signature_tlv_stream.signature = Some(&signature);
1402
1403                 let mut encoded_invoice = bytes;
1404                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1405
1406                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1407                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1408         }
1409
1410         #[test]
1411         fn builds_invoice_request_with_chain() {
1412                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
1413                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
1414
1415                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1416                         .amount_msats(1000)
1417                         .build().unwrap()
1418                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1419                         .chain(Network::Bitcoin).unwrap()
1420                         .build().unwrap()
1421                         .sign(payer_sign).unwrap();
1422                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1423                 assert_eq!(invoice_request.chain(), mainnet);
1424                 assert_eq!(tlv_stream.chain, None);
1425
1426                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1427                         .amount_msats(1000)
1428                         .chain(Network::Testnet)
1429                         .build().unwrap()
1430                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1431                         .chain(Network::Testnet).unwrap()
1432                         .build().unwrap()
1433                         .sign(payer_sign).unwrap();
1434                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1435                 assert_eq!(invoice_request.chain(), testnet);
1436                 assert_eq!(tlv_stream.chain, Some(&testnet));
1437
1438                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1439                         .amount_msats(1000)
1440                         .chain(Network::Bitcoin)
1441                         .chain(Network::Testnet)
1442                         .build().unwrap()
1443                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1444                         .chain(Network::Bitcoin).unwrap()
1445                         .build().unwrap()
1446                         .sign(payer_sign).unwrap();
1447                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1448                 assert_eq!(invoice_request.chain(), mainnet);
1449                 assert_eq!(tlv_stream.chain, None);
1450
1451                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1452                         .amount_msats(1000)
1453                         .chain(Network::Bitcoin)
1454                         .chain(Network::Testnet)
1455                         .build().unwrap()
1456                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1457                         .chain(Network::Bitcoin).unwrap()
1458                         .chain(Network::Testnet).unwrap()
1459                         .build().unwrap()
1460                         .sign(payer_sign).unwrap();
1461                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1462                 assert_eq!(invoice_request.chain(), testnet);
1463                 assert_eq!(tlv_stream.chain, Some(&testnet));
1464
1465                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1466                         .amount_msats(1000)
1467                         .chain(Network::Testnet)
1468                         .build().unwrap()
1469                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1470                         .chain(Network::Bitcoin)
1471                 {
1472                         Ok(_) => panic!("expected error"),
1473                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
1474                 }
1475
1476                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1477                         .amount_msats(1000)
1478                         .chain(Network::Testnet)
1479                         .build().unwrap()
1480                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1481                         .build()
1482                 {
1483                         Ok(_) => panic!("expected error"),
1484                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
1485                 }
1486         }
1487
1488         #[test]
1489         fn builds_invoice_request_with_amount() {
1490                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1491                         .amount_msats(1000)
1492                         .build().unwrap()
1493                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1494                         .amount_msats(1000).unwrap()
1495                         .build().unwrap()
1496                         .sign(payer_sign).unwrap();
1497                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1498                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1499                 assert_eq!(tlv_stream.amount, Some(1000));
1500
1501                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1502                         .amount_msats(1000)
1503                         .build().unwrap()
1504                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1505                         .amount_msats(1001).unwrap()
1506                         .amount_msats(1000).unwrap()
1507                         .build().unwrap()
1508                         .sign(payer_sign).unwrap();
1509                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1510                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1511                 assert_eq!(tlv_stream.amount, Some(1000));
1512
1513                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1514                         .amount_msats(1000)
1515                         .build().unwrap()
1516                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1517                         .amount_msats(1001).unwrap()
1518                         .build().unwrap()
1519                         .sign(payer_sign).unwrap();
1520                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1521                 assert_eq!(invoice_request.amount_msats(), Some(1001));
1522                 assert_eq!(tlv_stream.amount, Some(1001));
1523
1524                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1525                         .amount_msats(1000)
1526                         .build().unwrap()
1527                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1528                         .amount_msats(999)
1529                 {
1530                         Ok(_) => panic!("expected error"),
1531                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1532                 }
1533
1534                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1535                         .amount_msats(1000)
1536                         .supported_quantity(Quantity::Unbounded)
1537                         .build().unwrap()
1538                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1539                         .quantity(2).unwrap()
1540                         .amount_msats(1000)
1541                 {
1542                         Ok(_) => panic!("expected error"),
1543                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1544                 }
1545
1546                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1547                         .amount_msats(1000)
1548                         .build().unwrap()
1549                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1550                         .amount_msats(MAX_VALUE_MSAT + 1)
1551                 {
1552                         Ok(_) => panic!("expected error"),
1553                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1554                 }
1555
1556                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1557                         .amount_msats(1000)
1558                         .supported_quantity(Quantity::Unbounded)
1559                         .build().unwrap()
1560                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1561                         .amount_msats(1000).unwrap()
1562                         .quantity(2).unwrap()
1563                         .build()
1564                 {
1565                         Ok(_) => panic!("expected error"),
1566                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1567                 }
1568
1569                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1570                         .build().unwrap()
1571                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1572                         .build()
1573                 {
1574                         Ok(_) => panic!("expected error"),
1575                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingAmount),
1576                 }
1577
1578                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1579                         .amount_msats(1000)
1580                         .supported_quantity(Quantity::Unbounded)
1581                         .build().unwrap()
1582                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1583                         .quantity(u64::max_value()).unwrap()
1584                         .build()
1585                 {
1586                         Ok(_) => panic!("expected error"),
1587                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1588                 }
1589         }
1590
1591         #[test]
1592         fn builds_invoice_request_with_features() {
1593                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1594                         .amount_msats(1000)
1595                         .build().unwrap()
1596                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1597                         .features_unchecked(InvoiceRequestFeatures::unknown())
1598                         .build().unwrap()
1599                         .sign(payer_sign).unwrap();
1600                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1601                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::unknown());
1602                 assert_eq!(tlv_stream.features, Some(&InvoiceRequestFeatures::unknown()));
1603
1604                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1605                         .amount_msats(1000)
1606                         .build().unwrap()
1607                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1608                         .features_unchecked(InvoiceRequestFeatures::unknown())
1609                         .features_unchecked(InvoiceRequestFeatures::empty())
1610                         .build().unwrap()
1611                         .sign(payer_sign).unwrap();
1612                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1613                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
1614                 assert_eq!(tlv_stream.features, None);
1615         }
1616
1617         #[test]
1618         fn builds_invoice_request_with_quantity() {
1619                 let one = NonZeroU64::new(1).unwrap();
1620                 let ten = NonZeroU64::new(10).unwrap();
1621
1622                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1623                         .amount_msats(1000)
1624                         .supported_quantity(Quantity::One)
1625                         .build().unwrap()
1626                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1627                         .build().unwrap()
1628                         .sign(payer_sign).unwrap();
1629                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1630                 assert_eq!(invoice_request.quantity(), None);
1631                 assert_eq!(tlv_stream.quantity, None);
1632
1633                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1634                         .amount_msats(1000)
1635                         .supported_quantity(Quantity::One)
1636                         .build().unwrap()
1637                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1638                         .amount_msats(2_000).unwrap()
1639                         .quantity(2)
1640                 {
1641                         Ok(_) => panic!("expected error"),
1642                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnexpectedQuantity),
1643                 }
1644
1645                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1646                         .amount_msats(1000)
1647                         .supported_quantity(Quantity::Bounded(ten))
1648                         .build().unwrap()
1649                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1650                         .amount_msats(10_000).unwrap()
1651                         .quantity(10).unwrap()
1652                         .build().unwrap()
1653                         .sign(payer_sign).unwrap();
1654                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1655                 assert_eq!(invoice_request.amount_msats(), Some(10_000));
1656                 assert_eq!(tlv_stream.amount, Some(10_000));
1657
1658                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1659                         .amount_msats(1000)
1660                         .supported_quantity(Quantity::Bounded(ten))
1661                         .build().unwrap()
1662                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1663                         .amount_msats(11_000).unwrap()
1664                         .quantity(11)
1665                 {
1666                         Ok(_) => panic!("expected error"),
1667                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidQuantity),
1668                 }
1669
1670                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1671                         .amount_msats(1000)
1672                         .supported_quantity(Quantity::Unbounded)
1673                         .build().unwrap()
1674                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1675                         .amount_msats(2_000).unwrap()
1676                         .quantity(2).unwrap()
1677                         .build().unwrap()
1678                         .sign(payer_sign).unwrap();
1679                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1680                 assert_eq!(invoice_request.amount_msats(), Some(2_000));
1681                 assert_eq!(tlv_stream.amount, Some(2_000));
1682
1683                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1684                         .amount_msats(1000)
1685                         .supported_quantity(Quantity::Unbounded)
1686                         .build().unwrap()
1687                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1688                         .build()
1689                 {
1690                         Ok(_) => panic!("expected error"),
1691                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
1692                 }
1693
1694                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1695                         .amount_msats(1000)
1696                         .supported_quantity(Quantity::Bounded(one))
1697                         .build().unwrap()
1698                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1699                         .build()
1700                 {
1701                         Ok(_) => panic!("expected error"),
1702                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
1703                 }
1704         }
1705
1706         #[test]
1707         fn builds_invoice_request_with_payer_note() {
1708                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1709                         .amount_msats(1000)
1710                         .build().unwrap()
1711                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1712                         .payer_note("bar".into())
1713                         .build().unwrap()
1714                         .sign(payer_sign).unwrap();
1715                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1716                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("bar")));
1717                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
1718
1719                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1720                         .amount_msats(1000)
1721                         .build().unwrap()
1722                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1723                         .payer_note("bar".into())
1724                         .payer_note("baz".into())
1725                         .build().unwrap()
1726                         .sign(payer_sign).unwrap();
1727                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1728                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("baz")));
1729                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
1730         }
1731
1732         #[test]
1733         fn fails_signing_invoice_request() {
1734                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1735                         .amount_msats(1000)
1736                         .build().unwrap()
1737                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1738                         .build().unwrap()
1739                         .sign(fail_sign)
1740                 {
1741                         Ok(_) => panic!("expected error"),
1742                         Err(e) => assert_eq!(e, SignError::Signing),
1743                 }
1744
1745                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1746                         .amount_msats(1000)
1747                         .build().unwrap()
1748                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1749                         .build().unwrap()
1750                         .sign(recipient_sign)
1751                 {
1752                         Ok(_) => panic!("expected error"),
1753                         Err(e) => assert_eq!(e, SignError::Verification(secp256k1::Error::InvalidSignature)),
1754                 }
1755         }
1756
1757         #[test]
1758         fn fails_responding_with_unknown_required_features() {
1759                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1760                         .amount_msats(1000)
1761                         .build().unwrap()
1762                         .request_invoice(vec![42; 32], payer_pubkey()).unwrap()
1763                         .features_unchecked(InvoiceRequestFeatures::unknown())
1764                         .build().unwrap()
1765                         .sign(payer_sign).unwrap()
1766                         .respond_with_no_std(payment_paths(), payment_hash(), now())
1767                 {
1768                         Ok(_) => panic!("expected error"),
1769                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1770                 }
1771         }
1772
1773         #[test]
1774         fn parses_invoice_request_with_metadata() {
1775                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1776                         .amount_msats(1000)
1777                         .build().unwrap()
1778                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1779                         .build().unwrap()
1780                         .sign(payer_sign).unwrap();
1781
1782                 let mut buffer = Vec::new();
1783                 invoice_request.write(&mut buffer).unwrap();
1784
1785                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1786                         panic!("error parsing invoice_request: {:?}", e);
1787                 }
1788         }
1789
1790         #[test]
1791         fn parses_invoice_request_with_chain() {
1792                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1793                         .amount_msats(1000)
1794                         .build().unwrap()
1795                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1796                         .chain(Network::Bitcoin).unwrap()
1797                         .build().unwrap()
1798                         .sign(payer_sign).unwrap();
1799
1800                 let mut buffer = Vec::new();
1801                 invoice_request.write(&mut buffer).unwrap();
1802
1803                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1804                         panic!("error parsing invoice_request: {:?}", e);
1805                 }
1806
1807                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1808                         .amount_msats(1000)
1809                         .build().unwrap()
1810                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1811                         .chain_unchecked(Network::Testnet)
1812                         .build_unchecked()
1813                         .sign(payer_sign).unwrap();
1814
1815                 let mut buffer = Vec::new();
1816                 invoice_request.write(&mut buffer).unwrap();
1817
1818                 match InvoiceRequest::try_from(buffer) {
1819                         Ok(_) => panic!("expected error"),
1820                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnsupportedChain)),
1821                 }
1822         }
1823
1824         #[test]
1825         fn parses_invoice_request_with_amount() {
1826                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1827                         .amount_msats(1000)
1828                         .build().unwrap()
1829                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1830                         .build().unwrap()
1831                         .sign(payer_sign).unwrap();
1832
1833                 let mut buffer = Vec::new();
1834                 invoice_request.write(&mut buffer).unwrap();
1835
1836                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1837                         panic!("error parsing invoice_request: {:?}", e);
1838                 }
1839
1840                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1841                         .build().unwrap()
1842                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1843                         .amount_msats(1000).unwrap()
1844                         .build().unwrap()
1845                         .sign(payer_sign).unwrap();
1846
1847                 let mut buffer = Vec::new();
1848                 invoice_request.write(&mut buffer).unwrap();
1849
1850                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1851                         panic!("error parsing invoice_request: {:?}", e);
1852                 }
1853
1854                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1855                         .build().unwrap()
1856                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1857                         .build_unchecked()
1858                         .sign(payer_sign).unwrap();
1859
1860                 let mut buffer = Vec::new();
1861                 invoice_request.write(&mut buffer).unwrap();
1862
1863                 match InvoiceRequest::try_from(buffer) {
1864                         Ok(_) => panic!("expected error"),
1865                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1866                 }
1867
1868                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1869                         .amount_msats(1000)
1870                         .build().unwrap()
1871                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1872                         .amount_msats_unchecked(999)
1873                         .build_unchecked()
1874                         .sign(payer_sign).unwrap();
1875
1876                 let mut buffer = Vec::new();
1877                 invoice_request.write(&mut buffer).unwrap();
1878
1879                 match InvoiceRequest::try_from(buffer) {
1880                         Ok(_) => panic!("expected error"),
1881                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InsufficientAmount)),
1882                 }
1883
1884                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1885                         .amount(Amount::Currency { iso4217_code: *b"USD", amount: 1000 })
1886                         .build_unchecked()
1887                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1888                         .build_unchecked()
1889                         .sign(payer_sign).unwrap();
1890
1891                 let mut buffer = Vec::new();
1892                 invoice_request.write(&mut buffer).unwrap();
1893
1894                 match InvoiceRequest::try_from(buffer) {
1895                         Ok(_) => panic!("expected error"),
1896                         Err(e) => {
1897                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnsupportedCurrency));
1898                         },
1899                 }
1900
1901                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1902                         .amount_msats(1000)
1903                         .supported_quantity(Quantity::Unbounded)
1904                         .build().unwrap()
1905                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1906                         .quantity(u64::max_value()).unwrap()
1907                         .build_unchecked()
1908                         .sign(payer_sign).unwrap();
1909
1910                 let mut buffer = Vec::new();
1911                 invoice_request.write(&mut buffer).unwrap();
1912
1913                 match InvoiceRequest::try_from(buffer) {
1914                         Ok(_) => panic!("expected error"),
1915                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1916                 }
1917         }
1918
1919         #[test]
1920         fn parses_invoice_request_with_quantity() {
1921                 let one = NonZeroU64::new(1).unwrap();
1922                 let ten = NonZeroU64::new(10).unwrap();
1923
1924                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1925                         .amount_msats(1000)
1926                         .supported_quantity(Quantity::One)
1927                         .build().unwrap()
1928                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1929                         .build().unwrap()
1930                         .sign(payer_sign).unwrap();
1931
1932                 let mut buffer = Vec::new();
1933                 invoice_request.write(&mut buffer).unwrap();
1934
1935                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1936                         panic!("error parsing invoice_request: {:?}", e);
1937                 }
1938
1939                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1940                         .amount_msats(1000)
1941                         .supported_quantity(Quantity::One)
1942                         .build().unwrap()
1943                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1944                         .amount_msats(2_000).unwrap()
1945                         .quantity_unchecked(2)
1946                         .build_unchecked()
1947                         .sign(payer_sign).unwrap();
1948
1949                 let mut buffer = Vec::new();
1950                 invoice_request.write(&mut buffer).unwrap();
1951
1952                 match InvoiceRequest::try_from(buffer) {
1953                         Ok(_) => panic!("expected error"),
1954                         Err(e) => {
1955                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnexpectedQuantity));
1956                         },
1957                 }
1958
1959                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1960                         .amount_msats(1000)
1961                         .supported_quantity(Quantity::Bounded(ten))
1962                         .build().unwrap()
1963                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1964                         .amount_msats(10_000).unwrap()
1965                         .quantity(10).unwrap()
1966                         .build().unwrap()
1967                         .sign(payer_sign).unwrap();
1968
1969                 let mut buffer = Vec::new();
1970                 invoice_request.write(&mut buffer).unwrap();
1971
1972                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1973                         panic!("error parsing invoice_request: {:?}", e);
1974                 }
1975
1976                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1977                         .amount_msats(1000)
1978                         .supported_quantity(Quantity::Bounded(ten))
1979                         .build().unwrap()
1980                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1981                         .amount_msats(11_000).unwrap()
1982                         .quantity_unchecked(11)
1983                         .build_unchecked()
1984                         .sign(payer_sign).unwrap();
1985
1986                 let mut buffer = Vec::new();
1987                 invoice_request.write(&mut buffer).unwrap();
1988
1989                 match InvoiceRequest::try_from(buffer) {
1990                         Ok(_) => panic!("expected error"),
1991                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidQuantity)),
1992                 }
1993
1994                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1995                         .amount_msats(1000)
1996                         .supported_quantity(Quantity::Unbounded)
1997                         .build().unwrap()
1998                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1999                         .amount_msats(2_000).unwrap()
2000                         .quantity(2).unwrap()
2001                         .build().unwrap()
2002                         .sign(payer_sign).unwrap();
2003
2004                 let mut buffer = Vec::new();
2005                 invoice_request.write(&mut buffer).unwrap();
2006
2007                 if let Err(e) = InvoiceRequest::try_from(buffer) {
2008                         panic!("error parsing invoice_request: {:?}", e);
2009                 }
2010
2011                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2012                         .amount_msats(1000)
2013                         .supported_quantity(Quantity::Unbounded)
2014                         .build().unwrap()
2015                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2016                         .build_unchecked()
2017                         .sign(payer_sign).unwrap();
2018
2019                 let mut buffer = Vec::new();
2020                 invoice_request.write(&mut buffer).unwrap();
2021
2022                 match InvoiceRequest::try_from(buffer) {
2023                         Ok(_) => panic!("expected error"),
2024                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
2025                 }
2026
2027                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2028                         .amount_msats(1000)
2029                         .supported_quantity(Quantity::Bounded(one))
2030                         .build().unwrap()
2031                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2032                         .build_unchecked()
2033                         .sign(payer_sign).unwrap();
2034
2035                 let mut buffer = Vec::new();
2036                 invoice_request.write(&mut buffer).unwrap();
2037
2038                 match InvoiceRequest::try_from(buffer) {
2039                         Ok(_) => panic!("expected error"),
2040                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
2041                 }
2042         }
2043
2044         #[test]
2045         fn fails_parsing_invoice_request_without_metadata() {
2046                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
2047                         .amount_msats(1000)
2048                         .build().unwrap();
2049                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2050                         .build().unwrap();
2051                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
2052                 tlv_stream.0.metadata = None;
2053
2054                 let mut buffer = Vec::new();
2055                 tlv_stream.write(&mut buffer).unwrap();
2056
2057                 match InvoiceRequest::try_from(buffer) {
2058                         Ok(_) => panic!("expected error"),
2059                         Err(e) => {
2060                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPayerMetadata));
2061                         },
2062                 }
2063         }
2064
2065         #[test]
2066         fn fails_parsing_invoice_request_without_payer_id() {
2067                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
2068                         .amount_msats(1000)
2069                         .build().unwrap();
2070                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2071                         .build().unwrap();
2072                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
2073                 tlv_stream.2.payer_id = None;
2074
2075                 let mut buffer = Vec::new();
2076                 tlv_stream.write(&mut buffer).unwrap();
2077
2078                 match InvoiceRequest::try_from(buffer) {
2079                         Ok(_) => panic!("expected error"),
2080                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPayerId)),
2081                 }
2082         }
2083
2084         #[test]
2085         fn fails_parsing_invoice_request_without_node_id() {
2086                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
2087                         .amount_msats(1000)
2088                         .build().unwrap();
2089                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2090                         .build().unwrap();
2091                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
2092                 tlv_stream.1.node_id = None;
2093
2094                 let mut buffer = Vec::new();
2095                 tlv_stream.write(&mut buffer).unwrap();
2096
2097                 match InvoiceRequest::try_from(buffer) {
2098                         Ok(_) => panic!("expected error"),
2099                         Err(e) => {
2100                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
2101                         },
2102                 }
2103         }
2104
2105         #[test]
2106         fn fails_parsing_invoice_request_without_signature() {
2107                 let mut buffer = Vec::new();
2108                 OfferBuilder::new("foo".into(), recipient_pubkey())
2109                         .amount_msats(1000)
2110                         .build().unwrap()
2111                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2112                         .build().unwrap()
2113                         .contents
2114                         .write(&mut buffer).unwrap();
2115
2116                 match InvoiceRequest::try_from(buffer) {
2117                         Ok(_) => panic!("expected error"),
2118                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
2119                 }
2120         }
2121
2122         #[test]
2123         fn fails_parsing_invoice_request_with_invalid_signature() {
2124                 let mut invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
2125                         .amount_msats(1000)
2126                         .build().unwrap()
2127                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
2128                         .build().unwrap()
2129                         .sign(payer_sign).unwrap();
2130                 let last_signature_byte = invoice_request.bytes.last_mut().unwrap();
2131                 *last_signature_byte = last_signature_byte.wrapping_add(1);
2132
2133                 let mut buffer = Vec::new();
2134                 invoice_request.write(&mut buffer).unwrap();
2135
2136                 match InvoiceRequest::try_from(buffer) {
2137                         Ok(_) => panic!("expected error"),
2138                         Err(e) => {
2139                                 assert_eq!(e, Bolt12ParseError::InvalidSignature(secp256k1::Error::InvalidSignature));
2140                         },
2141                 }
2142         }
2143
2144         #[test]
2145         fn fails_parsing_invoice_request_with_extra_tlv_records() {
2146                 let secp_ctx = Secp256k1::new();
2147                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
2148                 let invoice_request = OfferBuilder::new("foo".into(), keys.public_key())
2149                         .amount_msats(1000)
2150                         .build().unwrap()
2151                         .request_invoice(vec![1; 32], keys.public_key()).unwrap()
2152                         .build().unwrap()
2153                         .sign(|message: &UnsignedInvoiceRequest|
2154                                 Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
2155                         )
2156                         .unwrap();
2157
2158                 let mut encoded_invoice_request = Vec::new();
2159                 invoice_request.write(&mut encoded_invoice_request).unwrap();
2160                 BigSize(1002).write(&mut encoded_invoice_request).unwrap();
2161                 BigSize(32).write(&mut encoded_invoice_request).unwrap();
2162                 [42u8; 32].write(&mut encoded_invoice_request).unwrap();
2163
2164                 match InvoiceRequest::try_from(encoded_invoice_request) {
2165                         Ok(_) => panic!("expected error"),
2166                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
2167                 }
2168         }
2169 }