_ 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 impl InvoiceRequest {
 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 metadata(&self) -> &[u8] {
 450                 self.contents.metadata()
 451         }
 452
 453         /// A chain from [`Offer::chains`] that the offer is valid for.
 454         pub fn chain(&self) -> ChainHash {
 455                 self.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                 self.contents.inner.amount_msats
 464         }
 465
 466         /// Features pertaining to requesting an invoice.
 467         pub fn features(&self) -> &InvoiceRequestFeatures {
 468                 &self.contents.inner.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                 self.contents.inner.quantity
 474         }
 475
 476         /// A possibly transient pubkey used to sign the invoice request.
 477         pub fn payer_id(&self) -> PublicKey {
 478                 self.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                 self.contents.inner.payer_note.as_ref()
 485                         .map(|payer_note| PrintableString(payer_note.as_str()))
 486         }
 487
 488         /// Signature of the invoice request using [`payer_id`].
 489         ///
 490         /// [`payer_id`]: Self::payer_id
 491         pub fn signature(&self) -> Signature {
 492                 self.signature
 493         }
 494
 495         /// Creates an [`InvoiceBuilder`] for the request with the given required fields and using the
 496         /// [`Duration`] since [`std::time::SystemTime::UNIX_EPOCH`] as the creation time.
 497         ///
 498         /// See [`InvoiceRequest::respond_with_no_std`] for further details where the aforementioned
 499         /// creation time is used for the `created_at` parameter.
 500         ///
 501         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 502         ///
 503         /// [`Duration`]: core::time::Duration
 504         #[cfg(feature = "std")]
 505         pub fn respond_with(
 506                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash
 507         ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, Bolt12SemanticError> {
 508                 let created_at = std::time::SystemTime::now()
 509                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 510                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 511
 512                 self.respond_with_no_std(payment_paths, payment_hash, created_at)
 513         }
 514
 515         /// Creates an [`InvoiceBuilder`] for the request with the given required fields.
 516         ///
 517         /// Unless [`InvoiceBuilder::relative_expiry`] is set, the invoice will expire two hours after
 518         /// `created_at`, which is used to set [`Bolt12Invoice::created_at`]. Useful for `no-std` builds
 519         /// where [`std::time::SystemTime`] is not available.
 520         ///
 521         /// The caller is expected to remember the preimage of `payment_hash` in order to claim a payment
 522         /// for the invoice.
 523         ///
 524         /// The `payment_paths` parameter is useful for maintaining the payment recipient's privacy. It
 525         /// must contain one or more elements ordered from most-preferred to least-preferred, if there's
 526         /// a preference. Note, however, that any privacy is lost if a public node id was used for
 527         /// [`Offer::signing_pubkey`].
 528         ///
 529         /// Errors if the request contains unknown required features.
 530         ///
 531         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 532         ///
 533         /// [`Bolt12Invoice::created_at`]: crate::offers::invoice::Bolt12Invoice::created_at
 534         pub fn respond_with_no_std(
 535                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 536                 created_at: core::time::Duration
 537         ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, Bolt12SemanticError> {
 538                 if self.features().requires_unknown_bits() {
 539                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 540                 }
 541
 542                 InvoiceBuilder::for_offer(self, payment_paths, created_at, payment_hash)
 543         }
 544
 545         /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
 546         /// derived signing keys from the originating [`Offer`] to sign the [`Bolt12Invoice`]. Must use
 547         /// the same [`ExpandedKey`] as the one used to create the offer.
 548         ///
 549         /// See [`InvoiceRequest::respond_with`] for further details.
 550         ///
 551         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 552         ///
 553         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 554         #[cfg(feature = "std")]
 555         pub fn verify_and_respond_using_derived_keys<T: secp256k1::Signing>(
 556                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 557                 expanded_key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 558         ) -> Result<InvoiceBuilder<DerivedSigningPubkey>, Bolt12SemanticError> {
 559                 let created_at = std::time::SystemTime::now()
 560                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 561                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 562
 563                 self.verify_and_respond_using_derived_keys_no_std(
 564                         payment_paths, payment_hash, created_at, expanded_key, secp_ctx
 565                 )
 566         }
 567
 568         /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
 569         /// derived signing keys from the originating [`Offer`] to sign the [`Bolt12Invoice`]. Must use
 570         /// the same [`ExpandedKey`] as the one used to create the offer.
 571         ///
 572         /// See [`InvoiceRequest::respond_with_no_std`] for further details.
 573         ///
 574         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 575         ///
 576         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 577         pub fn verify_and_respond_using_derived_keys_no_std<T: secp256k1::Signing>(
 578                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 579                 created_at: core::time::Duration, expanded_key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 580         ) -> Result<InvoiceBuilder<DerivedSigningPubkey>, Bolt12SemanticError> {
 581                 if self.features().requires_unknown_bits() {
 582                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 583                 }
 584
 585                 let keys = match self.verify(expanded_key, secp_ctx) {
 586                         Err(()) => return Err(Bolt12SemanticError::InvalidMetadata),
 587                         Ok(None) => return Err(Bolt12SemanticError::InvalidMetadata),
 588                         Ok(Some(keys)) => keys,
 589                 };
 590
 591                 InvoiceBuilder::for_offer_using_keys(self, payment_paths, created_at, payment_hash, keys)
 592         }
 593
 594         /// Verifies that the request was for an offer created using the given key. Returns the derived
 595         /// keys need to sign an [`Bolt12Invoice`] for the request if they could be extracted from the
 596         /// metadata.
 597         ///
 598         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 599         pub fn verify<T: secp256k1::Signing>(
 600                 &self, key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 601         ) -> Result<Option<KeyPair>, ()> {
 602                 self.contents.inner.offer.verify(&self.bytes, key, secp_ctx)
 603         }
 604
 605         #[cfg(test)]
 606         fn as_tlv_stream(&self) -> FullInvoiceRequestTlvStreamRef {
 607                 let (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream) =
 608                         self.contents.as_tlv_stream();
 609                 let signature_tlv_stream = SignatureTlvStreamRef {
 610                         signature: Some(&self.signature),
 611                 };
 612                 (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, signature_tlv_stream)
 613         }
 614 }
 615
 616 impl InvoiceRequestContents {
 617         pub(super) fn metadata(&self) -> &[u8] {
 618                 self.inner.metadata()
 619         }
 620
 621         pub(super) fn derives_keys(&self) -> bool {
 622                 self.inner.payer.0.derives_keys()
 623         }
 624
 625         pub(super) fn chain(&self) -> ChainHash {
 626                 self.inner.chain()
 627         }
 628
 629         pub(super) fn payer_id(&self) -> PublicKey {
 630                 self.payer_id
 631         }
 632
 633         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 634                 let (payer, offer, mut invoice_request) = self.inner.as_tlv_stream();
 635                 invoice_request.payer_id = Some(&self.payer_id);
 636                 (payer, offer, invoice_request)
 637         }
 638 }
 639
 640 impl InvoiceRequestContentsWithoutPayerId {
 641         pub(super) fn metadata(&self) -> &[u8] {
 642                 self.payer.0.as_bytes().map(|bytes| bytes.as_slice()).unwrap_or(&[])
 643         }
 644
 645         pub(super) fn chain(&self) -> ChainHash {
 646                 self.chain.unwrap_or_else(|| self.offer.implied_chain())
 647         }
 648
 649         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 650                 let payer = PayerTlvStreamRef {
 651                         metadata: self.payer.0.as_bytes(),
 652                 };
 653
 654                 let offer = self.offer.as_tlv_stream();
 655
 656                 let features = {
 657                         if self.features == InvoiceRequestFeatures::empty() { None }
 658                         else { Some(&self.features) }
 659                 };
 660
 661                 let invoice_request = InvoiceRequestTlvStreamRef {
 662                         chain: self.chain.as_ref(),
 663                         amount: self.amount_msats,
 664                         features,
 665                         quantity: self.quantity,
 666                         payer_id: None,
 667                         payer_note: self.payer_note.as_ref(),
 668                 };
 669
 670                 (payer, offer, invoice_request)
 671         }
 672 }
 673
 674 impl Writeable for UnsignedInvoiceRequest {
 675         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 676                 WithoutLength(&self.bytes).write(writer)
 677         }
 678 }
 679
 680 impl Writeable for InvoiceRequest {
 681         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 682                 WithoutLength(&self.bytes).write(writer)
 683         }
 684 }
 685
 686 impl Writeable for InvoiceRequestContents {
 687         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 688                 self.as_tlv_stream().write(writer)
 689         }
 690 }
 691
 692 /// Valid type range for invoice_request TLV records.
 693 pub(super) const INVOICE_REQUEST_TYPES: core::ops::Range<u64> = 80..160;
 694
 695 /// TLV record type for [`InvoiceRequest::payer_id`] and [`Refund::payer_id`].
 696 ///
 697 /// [`Refund::payer_id`]: crate::offers::refund::Refund::payer_id
 698 pub(super) const INVOICE_REQUEST_PAYER_ID_TYPE: u64 = 88;
 699
 700 tlv_stream!(InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef, INVOICE_REQUEST_TYPES, {
 701         (80, chain: ChainHash),
 702         (82, amount: (u64, HighZeroBytesDroppedBigSize)),
 703         (84, features: (InvoiceRequestFeatures, WithoutLength)),
 704         (86, quantity: (u64, HighZeroBytesDroppedBigSize)),
 705         (INVOICE_REQUEST_PAYER_ID_TYPE, payer_id: PublicKey),
 706         (89, payer_note: (String, WithoutLength)),
 707 });
 708
 709 type FullInvoiceRequestTlvStream =
 710         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, SignatureTlvStream);
 711
 712 #[cfg(test)]
 713 type FullInvoiceRequestTlvStreamRef<'a> = (
 714         PayerTlvStreamRef<'a>,
 715         OfferTlvStreamRef<'a>,
 716         InvoiceRequestTlvStreamRef<'a>,
 717         SignatureTlvStreamRef<'a>,
 718 );
 719
 720 impl SeekReadable for FullInvoiceRequestTlvStream {
 721         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 722                 let payer = SeekReadable::read(r)?;
 723                 let offer = SeekReadable::read(r)?;
 724                 let invoice_request = SeekReadable::read(r)?;
 725                 let signature = SeekReadable::read(r)?;
 726
 727                 Ok((payer, offer, invoice_request, signature))
 728         }
 729 }
 730
 731 type PartialInvoiceRequestTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
 732
 733 type PartialInvoiceRequestTlvStreamRef<'a> = (
 734         PayerTlvStreamRef<'a>,
 735         OfferTlvStreamRef<'a>,
 736         InvoiceRequestTlvStreamRef<'a>,
 737 );
 738
 739 impl TryFrom<Vec<u8>> for UnsignedInvoiceRequest {
 740         type Error = Bolt12ParseError;
 741
 742         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 743                 let invoice_request = ParsedMessage::<PartialInvoiceRequestTlvStream>::try_from(bytes)?;
 744                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
 745                 let (
 746                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
 747                 ) = tlv_stream;
 748                 let contents = InvoiceRequestContents::try_from(
 749                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 750                 )?;
 751
 752                 let tagged_hash = TaggedHash::new(SIGNATURE_TAG, &bytes);
 753
 754                 Ok(UnsignedInvoiceRequest { bytes, contents, tagged_hash })
 755         }
 756 }
 757
 758 impl TryFrom<Vec<u8>> for InvoiceRequest {
 759         type Error = Bolt12ParseError;
 760
 761         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 762                 let invoice_request = ParsedMessage::<FullInvoiceRequestTlvStream>::try_from(bytes)?;
 763                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
 764                 let (
 765                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
 766                         SignatureTlvStream { signature },
 767                 ) = tlv_stream;
 768                 let contents = InvoiceRequestContents::try_from(
 769                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 770                 )?;
 771
 772                 let signature = match signature {
 773                         None => return Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
 774                         Some(signature) => signature,
 775                 };
 776                 merkle::verify_signature(&signature, SIGNATURE_TAG, &bytes, contents.payer_id)?;
 777
 778                 Ok(InvoiceRequest { bytes, contents, signature })
 779         }
 780 }
 781
 782 impl TryFrom<PartialInvoiceRequestTlvStream> for InvoiceRequestContents {
 783         type Error = Bolt12SemanticError;
 784
 785         fn try_from(tlv_stream: PartialInvoiceRequestTlvStream) -> Result<Self, Self::Error> {
 786                 let (
 787                         PayerTlvStream { metadata },
 788                         offer_tlv_stream,
 789                         InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
 790                 ) = tlv_stream;
 791
 792                 let payer = match metadata {
 793                         None => return Err(Bolt12SemanticError::MissingPayerMetadata),
 794                         Some(metadata) => PayerContents(Metadata::Bytes(metadata)),
 795                 };
 796                 let offer = OfferContents::try_from(offer_tlv_stream)?;
 797
 798                 if !offer.supports_chain(chain.unwrap_or_else(|| offer.implied_chain())) {
 799                         return Err(Bolt12SemanticError::UnsupportedChain);
 800                 }
 801
 802                 if offer.amount().is_none() && amount.is_none() {
 803                         return Err(Bolt12SemanticError::MissingAmount);
 804                 }
 805
 806                 offer.check_quantity(quantity)?;
 807                 offer.check_amount_msats_for_quantity(amount, quantity)?;
 808
 809                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
 810
 811                 let payer_id = match payer_id {
 812                         None => return Err(Bolt12SemanticError::MissingPayerId),
 813                         Some(payer_id) => payer_id,
 814                 };
 815
 816                 Ok(InvoiceRequestContents {
 817                         inner: InvoiceRequestContentsWithoutPayerId {
 818                                 payer, offer, chain, amount_msats: amount, features, quantity, payer_note,
 819                         },
 820                         payer_id,
 821                 })
 822         }
 823 }
 824
 825 #[cfg(test)]
 826 mod tests {
 827         use super::{InvoiceRequest, InvoiceRequestTlvStreamRef, SIGNATURE_TAG, UnsignedInvoiceRequest};
 828
 829         use bitcoin::blockdata::constants::ChainHash;
 830         use bitcoin::network::constants::Network;
 831         use bitcoin::secp256k1::{KeyPair, Secp256k1, SecretKey, self};
 832         use core::convert::{Infallible, TryFrom};
 833         use core::num::NonZeroU64;
 834         #[cfg(feature = "std")]
 835         use core::time::Duration;
 836         use crate::sign::KeyMaterial;
 837         use crate::ln::features::InvoiceRequestFeatures;
 838         use crate::ln::inbound_payment::ExpandedKey;
 839         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 840         use crate::offers::invoice::{Bolt12Invoice, SIGNATURE_TAG as INVOICE_SIGNATURE_TAG};
 841         use crate::offers::merkle::{SignError, SignatureTlvStreamRef, TaggedHash, self};
 842         use crate::offers::offer::{Amount, OfferBuilder, OfferTlvStreamRef, Quantity};
 843         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
 844         use crate::offers::payer::PayerTlvStreamRef;
 845         use crate::offers::test_utils::*;
 846         use crate::util::ser::{BigSize, Writeable};
 847         use crate::util::string::PrintableString;
 848
 849         #[test]
 850         fn builds_invoice_request_with_defaults() {
 851                 let unsigned_invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 852                         .amount_msats(1000)
 853                         .build().unwrap()
 854                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 855                         .build().unwrap();
 856
 857                 let mut buffer = Vec::new();
 858                 unsigned_invoice_request.write(&mut buffer).unwrap();
 859
 860                 match UnsignedInvoiceRequest::try_from(buffer) {
 861                         Err(e) => panic!("error parsing unsigned invoice request: {:?}", e),
 862                         Ok(parsed) => {
 863                                 assert_eq!(parsed.bytes, unsigned_invoice_request.bytes);
 864                                 assert_eq!(parsed.tagged_hash, unsigned_invoice_request.tagged_hash);
 865                         },
 866                 }
 867
 868                 let invoice_request = unsigned_invoice_request.sign(payer_sign).unwrap();
 869
 870                 let mut buffer = Vec::new();
 871                 invoice_request.write(&mut buffer).unwrap();
 872
 873                 assert_eq!(invoice_request.bytes, buffer.as_slice());
 874                 assert_eq!(invoice_request.metadata(), &[1; 32]);
 875                 assert_eq!(invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
 876                 assert_eq!(invoice_request.amount_msats(), None);
 877                 assert_eq!(invoice_request.features(), &InvoiceRequestFeatures::empty());
 878                 assert_eq!(invoice_request.quantity(), None);
 879                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
 880                 assert_eq!(invoice_request.payer_note(), None);
 881                 assert!(
 882                         merkle::verify_signature(
 883                                 &invoice_request.signature, SIGNATURE_TAG, &invoice_request.bytes, payer_pubkey()
 884                         ).is_ok()
 885                 );
 886
 887                 assert_eq!(
 888                         invoice_request.as_tlv_stream(),
 889                         (
 890                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
 891                                 OfferTlvStreamRef {
 892                                         chains: None,
 893                                         metadata: None,
 894                                         currency: None,
 895                                         amount: Some(1000),
 896                                         description: Some(&String::from("foo")),
 897                                         features: None,
 898                                         absolute_expiry: None,
 899                                         paths: None,
 900                                         issuer: None,
 901                                         quantity_max: None,
 902                                         node_id: Some(&recipient_pubkey()),
 903                                 },
 904                                 InvoiceRequestTlvStreamRef {
 905                                         chain: None,
 906                                         amount: None,
 907                                         features: None,
 908                                         quantity: None,
 909                                         payer_id: Some(&payer_pubkey()),
 910                                         payer_note: None,
 911                                 },
 912                                 SignatureTlvStreamRef { signature: Some(&invoice_request.signature()) },
 913                         ),
 914                 );
 915
 916                 if let Err(e) = InvoiceRequest::try_from(buffer) {
 917                         panic!("error parsing invoice request: {:?}", e);
 918                 }
 919         }
 920
 921         #[cfg(feature = "std")]
 922         #[test]
 923         fn builds_invoice_request_from_offer_with_expiration() {
 924                 let future_expiry = Duration::from_secs(u64::max_value());
 925                 let past_expiry = Duration::from_secs(0);
 926
 927                 if let Err(e) = OfferBuilder::new("foo".into(), recipient_pubkey())
 928                         .amount_msats(1000)
 929                         .absolute_expiry(future_expiry)
 930                         .build().unwrap()
 931                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 932                         .build()
 933                 {
 934                         panic!("error building invoice_request: {:?}", e);
 935                 }
 936
 937                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 938                         .amount_msats(1000)
 939                         .absolute_expiry(past_expiry)
 940                         .build().unwrap()
 941                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 942                         .build()
 943                 {
 944                         Ok(_) => panic!("expected error"),
 945                         Err(e) => assert_eq!(e, Bolt12SemanticError::AlreadyExpired),
 946                 }
 947         }
 948
 949         #[test]
 950         fn builds_invoice_request_with_derived_metadata() {
 951                 let payer_id = payer_pubkey();
 952                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
 953                 let entropy = FixedEntropy {};
 954                 let secp_ctx = Secp256k1::new();
 955
 956                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
 957                         .amount_msats(1000)
 958                         .build().unwrap();
 959                 let invoice_request = offer
 960                         .request_invoice_deriving_metadata(payer_id, &expanded_key, &entropy)
 961                         .unwrap()
 962                         .build().unwrap()
 963                         .sign(payer_sign).unwrap();
 964                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
 965
 966                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
 967                         .unwrap()
 968                         .build().unwrap()
 969                         .sign(recipient_sign).unwrap();
 970                 assert!(invoice.verify(&expanded_key, &secp_ctx));
 971
 972                 // Fails verification with altered fields
 973                 let (
 974                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
 975                         mut invoice_tlv_stream, mut signature_tlv_stream
 976                 ) = invoice.as_tlv_stream();
 977                 invoice_request_tlv_stream.amount = Some(2000);
 978                 invoice_tlv_stream.amount = Some(2000);
 979
 980                 let tlv_stream =
 981                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
 982                 let mut bytes = Vec::new();
 983                 tlv_stream.write(&mut bytes).unwrap();
 984
 985                 let message = TaggedHash::new(INVOICE_SIGNATURE_TAG, &bytes);
 986                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
 987                 signature_tlv_stream.signature = Some(&signature);
 988
 989                 let mut encoded_invoice = bytes;
 990                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
 991
 992                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
 993                 assert!(!invoice.verify(&expanded_key, &secp_ctx));
 994
 995                 // Fails verification with altered metadata
 996                 let (
 997                         mut payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
 998                         mut signature_tlv_stream
 999                 ) = invoice.as_tlv_stream();
1000                 let metadata = payer_tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1001                 payer_tlv_stream.metadata = Some(&metadata);
1002
1003                 let tlv_stream =
1004                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1005                 let mut bytes = Vec::new();
1006                 tlv_stream.write(&mut bytes).unwrap();
1007
1008                 let message = TaggedHash::new(INVOICE_SIGNATURE_TAG, &bytes);
1009                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1010                 signature_tlv_stream.signature = Some(&signature);
1011
1012                 let mut encoded_invoice = bytes;
1013                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1014
1015                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1016                 assert!(!invoice.verify(&expanded_key, &secp_ctx));
1017         }
1018
1019         #[test]
1020         fn builds_invoice_request_with_derived_payer_id() {
1021                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1022                 let entropy = FixedEntropy {};
1023                 let secp_ctx = Secp256k1::new();
1024
1025                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1026                         .amount_msats(1000)
1027                         .build().unwrap();
1028                 let invoice_request = offer
1029                         .request_invoice_deriving_payer_id(&expanded_key, &entropy, &secp_ctx)
1030                         .unwrap()
1031                         .build_and_sign()
1032                         .unwrap();
1033
1034                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
1035                         .unwrap()
1036                         .build().unwrap()
1037                         .sign(recipient_sign).unwrap();
1038                 assert!(invoice.verify(&expanded_key, &secp_ctx));
1039
1040                 // Fails verification with altered fields
1041                 let (
1042                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
1043                         mut invoice_tlv_stream, mut signature_tlv_stream
1044                 ) = invoice.as_tlv_stream();
1045                 invoice_request_tlv_stream.amount = Some(2000);
1046                 invoice_tlv_stream.amount = Some(2000);
1047
1048                 let tlv_stream =
1049                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1050                 let mut bytes = Vec::new();
1051                 tlv_stream.write(&mut bytes).unwrap();
1052
1053                 let message = TaggedHash::new(INVOICE_SIGNATURE_TAG, &bytes);
1054                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1055                 signature_tlv_stream.signature = Some(&signature);
1056
1057                 let mut encoded_invoice = bytes;
1058                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1059
1060                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1061                 assert!(!invoice.verify(&expanded_key, &secp_ctx));
1062
1063                 // Fails verification with altered payer id
1064                 let (
1065                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream, invoice_tlv_stream,
1066                         mut signature_tlv_stream
1067                 ) = invoice.as_tlv_stream();
1068                 let payer_id = pubkey(1);
1069                 invoice_request_tlv_stream.payer_id = Some(&payer_id);
1070
1071                 let tlv_stream =
1072                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1073                 let mut bytes = Vec::new();
1074                 tlv_stream.write(&mut bytes).unwrap();
1075
1076                 let message = TaggedHash::new(INVOICE_SIGNATURE_TAG, &bytes);
1077                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1078                 signature_tlv_stream.signature = Some(&signature);
1079
1080                 let mut encoded_invoice = bytes;
1081                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1082
1083                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1084                 assert!(!invoice.verify(&expanded_key, &secp_ctx));
1085         }
1086
1087         #[test]
1088         fn builds_invoice_request_with_chain() {
1089                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
1090                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
1091
1092                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1093                         .amount_msats(1000)
1094                         .build().unwrap()
1095                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1096                         .chain(Network::Bitcoin).unwrap()
1097                         .build().unwrap()
1098                         .sign(payer_sign).unwrap();
1099                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1100                 assert_eq!(invoice_request.chain(), mainnet);
1101                 assert_eq!(tlv_stream.chain, None);
1102
1103                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1104                         .amount_msats(1000)
1105                         .chain(Network::Testnet)
1106                         .build().unwrap()
1107                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1108                         .chain(Network::Testnet).unwrap()
1109                         .build().unwrap()
1110                         .sign(payer_sign).unwrap();
1111                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1112                 assert_eq!(invoice_request.chain(), testnet);
1113                 assert_eq!(tlv_stream.chain, Some(&testnet));
1114
1115                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1116                         .amount_msats(1000)
1117                         .chain(Network::Bitcoin)
1118                         .chain(Network::Testnet)
1119                         .build().unwrap()
1120                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1121                         .chain(Network::Bitcoin).unwrap()
1122                         .build().unwrap()
1123                         .sign(payer_sign).unwrap();
1124                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1125                 assert_eq!(invoice_request.chain(), mainnet);
1126                 assert_eq!(tlv_stream.chain, None);
1127
1128                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1129                         .amount_msats(1000)
1130                         .chain(Network::Bitcoin)
1131                         .chain(Network::Testnet)
1132                         .build().unwrap()
1133                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1134                         .chain(Network::Bitcoin).unwrap()
1135                         .chain(Network::Testnet).unwrap()
1136                         .build().unwrap()
1137                         .sign(payer_sign).unwrap();
1138                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1139                 assert_eq!(invoice_request.chain(), testnet);
1140                 assert_eq!(tlv_stream.chain, Some(&testnet));
1141
1142                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1143                         .amount_msats(1000)
1144                         .chain(Network::Testnet)
1145                         .build().unwrap()
1146                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1147                         .chain(Network::Bitcoin)
1148                 {
1149                         Ok(_) => panic!("expected error"),
1150                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
1151                 }
1152
1153                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1154                         .amount_msats(1000)
1155                         .chain(Network::Testnet)
1156                         .build().unwrap()
1157                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1158                         .build()
1159                 {
1160                         Ok(_) => panic!("expected error"),
1161                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
1162                 }
1163         }
1164
1165         #[test]
1166         fn builds_invoice_request_with_amount() {
1167                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1168                         .amount_msats(1000)
1169                         .build().unwrap()
1170                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1171                         .amount_msats(1000).unwrap()
1172                         .build().unwrap()
1173                         .sign(payer_sign).unwrap();
1174                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1175                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1176                 assert_eq!(tlv_stream.amount, Some(1000));
1177
1178                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1179                         .amount_msats(1000)
1180                         .build().unwrap()
1181                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1182                         .amount_msats(1001).unwrap()
1183                         .amount_msats(1000).unwrap()
1184                         .build().unwrap()
1185                         .sign(payer_sign).unwrap();
1186                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1187                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1188                 assert_eq!(tlv_stream.amount, Some(1000));
1189
1190                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1191                         .amount_msats(1000)
1192                         .build().unwrap()
1193                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1194                         .amount_msats(1001).unwrap()
1195                         .build().unwrap()
1196                         .sign(payer_sign).unwrap();
1197                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1198                 assert_eq!(invoice_request.amount_msats(), Some(1001));
1199                 assert_eq!(tlv_stream.amount, Some(1001));
1200
1201                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1202                         .amount_msats(1000)
1203                         .build().unwrap()
1204                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1205                         .amount_msats(999)
1206                 {
1207                         Ok(_) => panic!("expected error"),
1208                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1209                 }
1210
1211                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1212                         .amount_msats(1000)
1213                         .supported_quantity(Quantity::Unbounded)
1214                         .build().unwrap()
1215                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1216                         .quantity(2).unwrap()
1217                         .amount_msats(1000)
1218                 {
1219                         Ok(_) => panic!("expected error"),
1220                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1221                 }
1222
1223                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1224                         .amount_msats(1000)
1225                         .build().unwrap()
1226                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1227                         .amount_msats(MAX_VALUE_MSAT + 1)
1228                 {
1229                         Ok(_) => panic!("expected error"),
1230                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1231                 }
1232
1233                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1234                         .amount_msats(1000)
1235                         .supported_quantity(Quantity::Unbounded)
1236                         .build().unwrap()
1237                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1238                         .amount_msats(1000).unwrap()
1239                         .quantity(2).unwrap()
1240                         .build()
1241                 {
1242                         Ok(_) => panic!("expected error"),
1243                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1244                 }
1245
1246                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1247                         .build().unwrap()
1248                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1249                         .build()
1250                 {
1251                         Ok(_) => panic!("expected error"),
1252                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingAmount),
1253                 }
1254
1255                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1256                         .amount_msats(1000)
1257                         .supported_quantity(Quantity::Unbounded)
1258                         .build().unwrap()
1259                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1260                         .quantity(u64::max_value()).unwrap()
1261                         .build()
1262                 {
1263                         Ok(_) => panic!("expected error"),
1264                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1265                 }
1266         }
1267
1268         #[test]
1269         fn builds_invoice_request_with_features() {
1270                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1271                         .amount_msats(1000)
1272                         .build().unwrap()
1273                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1274                         .features_unchecked(InvoiceRequestFeatures::unknown())
1275                         .build().unwrap()
1276                         .sign(payer_sign).unwrap();
1277                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1278                 assert_eq!(invoice_request.features(), &InvoiceRequestFeatures::unknown());
1279                 assert_eq!(tlv_stream.features, Some(&InvoiceRequestFeatures::unknown()));
1280
1281                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1282                         .amount_msats(1000)
1283                         .build().unwrap()
1284                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1285                         .features_unchecked(InvoiceRequestFeatures::unknown())
1286                         .features_unchecked(InvoiceRequestFeatures::empty())
1287                         .build().unwrap()
1288                         .sign(payer_sign).unwrap();
1289                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1290                 assert_eq!(invoice_request.features(), &InvoiceRequestFeatures::empty());
1291                 assert_eq!(tlv_stream.features, None);
1292         }
1293
1294         #[test]
1295         fn builds_invoice_request_with_quantity() {
1296                 let one = NonZeroU64::new(1).unwrap();
1297                 let ten = NonZeroU64::new(10).unwrap();
1298
1299                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1300                         .amount_msats(1000)
1301                         .supported_quantity(Quantity::One)
1302                         .build().unwrap()
1303                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1304                         .build().unwrap()
1305                         .sign(payer_sign).unwrap();
1306                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1307                 assert_eq!(invoice_request.quantity(), None);
1308                 assert_eq!(tlv_stream.quantity, None);
1309
1310                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1311                         .amount_msats(1000)
1312                         .supported_quantity(Quantity::One)
1313                         .build().unwrap()
1314                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1315                         .amount_msats(2_000).unwrap()
1316                         .quantity(2)
1317                 {
1318                         Ok(_) => panic!("expected error"),
1319                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnexpectedQuantity),
1320                 }
1321
1322                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1323                         .amount_msats(1000)
1324                         .supported_quantity(Quantity::Bounded(ten))
1325                         .build().unwrap()
1326                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1327                         .amount_msats(10_000).unwrap()
1328                         .quantity(10).unwrap()
1329                         .build().unwrap()
1330                         .sign(payer_sign).unwrap();
1331                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1332                 assert_eq!(invoice_request.amount_msats(), Some(10_000));
1333                 assert_eq!(tlv_stream.amount, Some(10_000));
1334
1335                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1336                         .amount_msats(1000)
1337                         .supported_quantity(Quantity::Bounded(ten))
1338                         .build().unwrap()
1339                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1340                         .amount_msats(11_000).unwrap()
1341                         .quantity(11)
1342                 {
1343                         Ok(_) => panic!("expected error"),
1344                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidQuantity),
1345                 }
1346
1347                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1348                         .amount_msats(1000)
1349                         .supported_quantity(Quantity::Unbounded)
1350                         .build().unwrap()
1351                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1352                         .amount_msats(2_000).unwrap()
1353                         .quantity(2).unwrap()
1354                         .build().unwrap()
1355                         .sign(payer_sign).unwrap();
1356                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1357                 assert_eq!(invoice_request.amount_msats(), Some(2_000));
1358                 assert_eq!(tlv_stream.amount, Some(2_000));
1359
1360                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1361                         .amount_msats(1000)
1362                         .supported_quantity(Quantity::Unbounded)
1363                         .build().unwrap()
1364                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1365                         .build()
1366                 {
1367                         Ok(_) => panic!("expected error"),
1368                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
1369                 }
1370
1371                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1372                         .amount_msats(1000)
1373                         .supported_quantity(Quantity::Bounded(one))
1374                         .build().unwrap()
1375                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1376                         .build()
1377                 {
1378                         Ok(_) => panic!("expected error"),
1379                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
1380                 }
1381         }
1382
1383         #[test]
1384         fn builds_invoice_request_with_payer_note() {
1385                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1386                         .amount_msats(1000)
1387                         .build().unwrap()
1388                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1389                         .payer_note("bar".into())
1390                         .build().unwrap()
1391                         .sign(payer_sign).unwrap();
1392                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1393                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("bar")));
1394                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
1395
1396                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1397                         .amount_msats(1000)
1398                         .build().unwrap()
1399                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1400                         .payer_note("bar".into())
1401                         .payer_note("baz".into())
1402                         .build().unwrap()
1403                         .sign(payer_sign).unwrap();
1404                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1405                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("baz")));
1406                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
1407         }
1408
1409         #[test]
1410         fn fails_signing_invoice_request() {
1411                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1412                         .amount_msats(1000)
1413                         .build().unwrap()
1414                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1415                         .build().unwrap()
1416                         .sign(|_| Err(()))
1417                 {
1418                         Ok(_) => panic!("expected error"),
1419                         Err(e) => assert_eq!(e, SignError::Signing(())),
1420                 }
1421
1422                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1423                         .amount_msats(1000)
1424                         .build().unwrap()
1425                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1426                         .build().unwrap()
1427                         .sign(recipient_sign)
1428                 {
1429                         Ok(_) => panic!("expected error"),
1430                         Err(e) => assert_eq!(e, SignError::Verification(secp256k1::Error::InvalidSignature)),
1431                 }
1432         }
1433
1434         #[test]
1435         fn fails_responding_with_unknown_required_features() {
1436                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1437                         .amount_msats(1000)
1438                         .build().unwrap()
1439                         .request_invoice(vec![42; 32], payer_pubkey()).unwrap()
1440                         .features_unchecked(InvoiceRequestFeatures::unknown())
1441                         .build().unwrap()
1442                         .sign(payer_sign).unwrap()
1443                         .respond_with_no_std(payment_paths(), payment_hash(), now())
1444                 {
1445                         Ok(_) => panic!("expected error"),
1446                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1447                 }
1448         }
1449
1450         #[test]
1451         fn parses_invoice_request_with_metadata() {
1452                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1453                         .amount_msats(1000)
1454                         .build().unwrap()
1455                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1456                         .build().unwrap()
1457                         .sign(payer_sign).unwrap();
1458
1459                 let mut buffer = Vec::new();
1460                 invoice_request.write(&mut buffer).unwrap();
1461
1462                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1463                         panic!("error parsing invoice_request: {:?}", e);
1464                 }
1465         }
1466
1467         #[test]
1468         fn parses_invoice_request_with_chain() {
1469                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1470                         .amount_msats(1000)
1471                         .build().unwrap()
1472                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1473                         .chain(Network::Bitcoin).unwrap()
1474                         .build().unwrap()
1475                         .sign(payer_sign).unwrap();
1476
1477                 let mut buffer = Vec::new();
1478                 invoice_request.write(&mut buffer).unwrap();
1479
1480                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1481                         panic!("error parsing invoice_request: {:?}", e);
1482                 }
1483
1484                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1485                         .amount_msats(1000)
1486                         .build().unwrap()
1487                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1488                         .chain_unchecked(Network::Testnet)
1489                         .build_unchecked()
1490                         .sign(payer_sign).unwrap();
1491
1492                 let mut buffer = Vec::new();
1493                 invoice_request.write(&mut buffer).unwrap();
1494
1495                 match InvoiceRequest::try_from(buffer) {
1496                         Ok(_) => panic!("expected error"),
1497                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnsupportedChain)),
1498                 }
1499         }
1500
1501         #[test]
1502         fn parses_invoice_request_with_amount() {
1503                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1504                         .amount_msats(1000)
1505                         .build().unwrap()
1506                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1507                         .build().unwrap()
1508                         .sign(payer_sign).unwrap();
1509
1510                 let mut buffer = Vec::new();
1511                 invoice_request.write(&mut buffer).unwrap();
1512
1513                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1514                         panic!("error parsing invoice_request: {:?}", e);
1515                 }
1516
1517                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1518                         .build().unwrap()
1519                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1520                         .amount_msats(1000).unwrap()
1521                         .build().unwrap()
1522                         .sign(payer_sign).unwrap();
1523
1524                 let mut buffer = Vec::new();
1525                 invoice_request.write(&mut buffer).unwrap();
1526
1527                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1528                         panic!("error parsing invoice_request: {:?}", e);
1529                 }
1530
1531                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1532                         .build().unwrap()
1533                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1534                         .build_unchecked()
1535                         .sign(payer_sign).unwrap();
1536
1537                 let mut buffer = Vec::new();
1538                 invoice_request.write(&mut buffer).unwrap();
1539
1540                 match InvoiceRequest::try_from(buffer) {
1541                         Ok(_) => panic!("expected error"),
1542                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1543                 }
1544
1545                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1546                         .amount_msats(1000)
1547                         .build().unwrap()
1548                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1549                         .amount_msats_unchecked(999)
1550                         .build_unchecked()
1551                         .sign(payer_sign).unwrap();
1552
1553                 let mut buffer = Vec::new();
1554                 invoice_request.write(&mut buffer).unwrap();
1555
1556                 match InvoiceRequest::try_from(buffer) {
1557                         Ok(_) => panic!("expected error"),
1558                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InsufficientAmount)),
1559                 }
1560
1561                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1562                         .amount(Amount::Currency { iso4217_code: *b"USD", amount: 1000 })
1563                         .build_unchecked()
1564                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1565                         .build_unchecked()
1566                         .sign(payer_sign).unwrap();
1567
1568                 let mut buffer = Vec::new();
1569                 invoice_request.write(&mut buffer).unwrap();
1570
1571                 match InvoiceRequest::try_from(buffer) {
1572                         Ok(_) => panic!("expected error"),
1573                         Err(e) => {
1574                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnsupportedCurrency));
1575                         },
1576                 }
1577
1578                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1579                         .amount_msats(1000)
1580                         .supported_quantity(Quantity::Unbounded)
1581                         .build().unwrap()
1582                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1583                         .quantity(u64::max_value()).unwrap()
1584                         .build_unchecked()
1585                         .sign(payer_sign).unwrap();
1586
1587                 let mut buffer = Vec::new();
1588                 invoice_request.write(&mut buffer).unwrap();
1589
1590                 match InvoiceRequest::try_from(buffer) {
1591                         Ok(_) => panic!("expected error"),
1592                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1593                 }
1594         }
1595
1596         #[test]
1597         fn parses_invoice_request_with_quantity() {
1598                 let one = NonZeroU64::new(1).unwrap();
1599                 let ten = NonZeroU64::new(10).unwrap();
1600
1601                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1602                         .amount_msats(1000)
1603                         .supported_quantity(Quantity::One)
1604                         .build().unwrap()
1605                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1606                         .build().unwrap()
1607                         .sign(payer_sign).unwrap();
1608
1609                 let mut buffer = Vec::new();
1610                 invoice_request.write(&mut buffer).unwrap();
1611
1612                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1613                         panic!("error parsing invoice_request: {:?}", e);
1614                 }
1615
1616                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1617                         .amount_msats(1000)
1618                         .supported_quantity(Quantity::One)
1619                         .build().unwrap()
1620                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1621                         .amount_msats(2_000).unwrap()
1622                         .quantity_unchecked(2)
1623                         .build_unchecked()
1624                         .sign(payer_sign).unwrap();
1625
1626                 let mut buffer = Vec::new();
1627                 invoice_request.write(&mut buffer).unwrap();
1628
1629                 match InvoiceRequest::try_from(buffer) {
1630                         Ok(_) => panic!("expected error"),
1631                         Err(e) => {
1632                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnexpectedQuantity));
1633                         },
1634                 }
1635
1636                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1637                         .amount_msats(1000)
1638                         .supported_quantity(Quantity::Bounded(ten))
1639                         .build().unwrap()
1640                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1641                         .amount_msats(10_000).unwrap()
1642                         .quantity(10).unwrap()
1643                         .build().unwrap()
1644                         .sign(payer_sign).unwrap();
1645
1646                 let mut buffer = Vec::new();
1647                 invoice_request.write(&mut buffer).unwrap();
1648
1649                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1650                         panic!("error parsing invoice_request: {:?}", e);
1651                 }
1652
1653                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1654                         .amount_msats(1000)
1655                         .supported_quantity(Quantity::Bounded(ten))
1656                         .build().unwrap()
1657                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1658                         .amount_msats(11_000).unwrap()
1659                         .quantity_unchecked(11)
1660                         .build_unchecked()
1661                         .sign(payer_sign).unwrap();
1662
1663                 let mut buffer = Vec::new();
1664                 invoice_request.write(&mut buffer).unwrap();
1665
1666                 match InvoiceRequest::try_from(buffer) {
1667                         Ok(_) => panic!("expected error"),
1668                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidQuantity)),
1669                 }
1670
1671                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1672                         .amount_msats(1000)
1673                         .supported_quantity(Quantity::Unbounded)
1674                         .build().unwrap()
1675                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1676                         .amount_msats(2_000).unwrap()
1677                         .quantity(2).unwrap()
1678                         .build().unwrap()
1679                         .sign(payer_sign).unwrap();
1680
1681                 let mut buffer = Vec::new();
1682                 invoice_request.write(&mut buffer).unwrap();
1683
1684                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1685                         panic!("error parsing invoice_request: {:?}", e);
1686                 }
1687
1688                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1689                         .amount_msats(1000)
1690                         .supported_quantity(Quantity::Unbounded)
1691                         .build().unwrap()
1692                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1693                         .build_unchecked()
1694                         .sign(payer_sign).unwrap();
1695
1696                 let mut buffer = Vec::new();
1697                 invoice_request.write(&mut buffer).unwrap();
1698
1699                 match InvoiceRequest::try_from(buffer) {
1700                         Ok(_) => panic!("expected error"),
1701                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
1702                 }
1703
1704                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1705                         .amount_msats(1000)
1706                         .supported_quantity(Quantity::Bounded(one))
1707                         .build().unwrap()
1708                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1709                         .build_unchecked()
1710                         .sign(payer_sign).unwrap();
1711
1712                 let mut buffer = Vec::new();
1713                 invoice_request.write(&mut buffer).unwrap();
1714
1715                 match InvoiceRequest::try_from(buffer) {
1716                         Ok(_) => panic!("expected error"),
1717                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
1718                 }
1719         }
1720
1721         #[test]
1722         fn fails_parsing_invoice_request_without_metadata() {
1723                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1724                         .amount_msats(1000)
1725                         .build().unwrap();
1726                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1727                         .build().unwrap();
1728                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
1729                 tlv_stream.0.metadata = None;
1730
1731                 let mut buffer = Vec::new();
1732                 tlv_stream.write(&mut buffer).unwrap();
1733
1734                 match InvoiceRequest::try_from(buffer) {
1735                         Ok(_) => panic!("expected error"),
1736                         Err(e) => {
1737                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPayerMetadata));
1738                         },
1739                 }
1740         }
1741
1742         #[test]
1743         fn fails_parsing_invoice_request_without_payer_id() {
1744                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1745                         .amount_msats(1000)
1746                         .build().unwrap();
1747                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1748                         .build().unwrap();
1749                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
1750                 tlv_stream.2.payer_id = None;
1751
1752                 let mut buffer = Vec::new();
1753                 tlv_stream.write(&mut buffer).unwrap();
1754
1755                 match InvoiceRequest::try_from(buffer) {
1756                         Ok(_) => panic!("expected error"),
1757                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPayerId)),
1758                 }
1759         }
1760
1761         #[test]
1762         fn fails_parsing_invoice_request_without_node_id() {
1763                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1764                         .amount_msats(1000)
1765                         .build().unwrap();
1766                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1767                         .build().unwrap();
1768                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
1769                 tlv_stream.1.node_id = None;
1770
1771                 let mut buffer = Vec::new();
1772                 tlv_stream.write(&mut buffer).unwrap();
1773
1774                 match InvoiceRequest::try_from(buffer) {
1775                         Ok(_) => panic!("expected error"),
1776                         Err(e) => {
1777                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1778                         },
1779                 }
1780         }
1781
1782         #[test]
1783         fn fails_parsing_invoice_request_without_signature() {
1784                 let mut buffer = Vec::new();
1785                 OfferBuilder::new("foo".into(), recipient_pubkey())
1786                         .amount_msats(1000)
1787                         .build().unwrap()
1788                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1789                         .build().unwrap()
1790                         .contents
1791                         .write(&mut buffer).unwrap();
1792
1793                 match InvoiceRequest::try_from(buffer) {
1794                         Ok(_) => panic!("expected error"),
1795                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
1796                 }
1797         }
1798
1799         #[test]
1800         fn fails_parsing_invoice_request_with_invalid_signature() {
1801                 let mut invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1802                         .amount_msats(1000)
1803                         .build().unwrap()
1804                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1805                         .build().unwrap()
1806                         .sign(payer_sign).unwrap();
1807                 let last_signature_byte = invoice_request.bytes.last_mut().unwrap();
1808                 *last_signature_byte = last_signature_byte.wrapping_add(1);
1809
1810                 let mut buffer = Vec::new();
1811                 invoice_request.write(&mut buffer).unwrap();
1812
1813                 match InvoiceRequest::try_from(buffer) {
1814                         Ok(_) => panic!("expected error"),
1815                         Err(e) => {
1816                                 assert_eq!(e, Bolt12ParseError::InvalidSignature(secp256k1::Error::InvalidSignature));
1817                         },
1818                 }
1819         }
1820
1821         #[test]
1822         fn fails_parsing_invoice_request_with_extra_tlv_records() {
1823                 let secp_ctx = Secp256k1::new();
1824                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1825                 let invoice_request = OfferBuilder::new("foo".into(), keys.public_key())
1826                         .amount_msats(1000)
1827                         .build().unwrap()
1828                         .request_invoice(vec![1; 32], keys.public_key()).unwrap()
1829                         .build().unwrap()
1830                         .sign::<_, Infallible>(
1831                                 |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
1832                         )
1833                         .unwrap();
1834
1835                 let mut encoded_invoice_request = Vec::new();
1836                 invoice_request.write(&mut encoded_invoice_request).unwrap();
1837                 BigSize(1002).write(&mut encoded_invoice_request).unwrap();
1838                 BigSize(32).write(&mut encoded_invoice_request).unwrap();
1839                 [42u8; 32].write(&mut encoded_invoice_request).unwrap();
1840
1841                 match InvoiceRequest::try_from(encoded_invoice_request) {
1842                         Ok(_) => panic!("expected error"),
1843                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1844                 }
1845         }
1846 }