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