_ Git - rust-lightning/blob - lightning/src/offers/invoice_request.rs

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! Data structures and encoding for `invoice_request` messages.
  11 //!
  12 //! An [`InvoiceRequest`] can be built from a parsed [`Offer`] as an "offer to be paid". It is
  13 //! typically constructed by a customer and sent to the merchant who had published the corresponding
  14 //! offer. The recipient of the request responds with a [`Bolt12Invoice`].
  15 //!
  16 //! For an "offer for money" (e.g., refund, ATM withdrawal), where an offer doesn't exist as a
  17 //! precursor, see [`Refund`].
  18 //!
  19 //! [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
  20 //! [`Refund`]: crate::offers::refund::Refund
  21 //!
  22 //! ```
  23 //! extern crate bitcoin;
  24 //! extern crate lightning;
  25 //!
  26 //! use bitcoin::network::constants::Network;
  27 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
  28 //! use core::convert::Infallible;
  29 //! use lightning::ln::features::OfferFeatures;
  30 //! use lightning::offers::offer::Offer;
  31 //! use lightning::util::ser::Writeable;
  32 //!
  33 //! # fn parse() -> Result<(), lightning::offers::parse::Bolt12ParseError> {
  34 //! let secp_ctx = Secp256k1::new();
  35 //! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32])?);
  36 //! let pubkey = PublicKey::from(keys);
  37 //! let mut buffer = Vec::new();
  38 //!
  39 //! "lno1qcp4256ypq"
  40 //!     .parse::<Offer>()?
  41 //!     .request_invoice(vec![42; 64], pubkey)?
  42 //!     .chain(Network::Testnet)?
  43 //!     .amount_msats(1000)?
  44 //!     .quantity(5)?
  45 //!     .payer_note("foo".to_string())
  46 //!     .build()?
  47 //!     .sign::<_, Infallible>(
  48 //!         |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
  49 //!     )
  50 //!     .expect("failed verifying signature")
  51 //!     .write(&mut buffer)
  52 //!     .unwrap();
  53 //! # Ok(())
  54 //! # }
  55 //! ```
  56
  57 use bitcoin::blockdata::constants::ChainHash;
  58 use bitcoin::network::constants::Network;
  59 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, self};
  60 use bitcoin::secp256k1::schnorr::Signature;
  61 use core::convert::{AsRef, Infallible, TryFrom};
  62 use core::ops::Deref;
  63 use crate::sign::EntropySource;
  64 use crate::io;
  65 use crate::blinded_path::BlindedPath;
  66 use crate::ln::PaymentHash;
  67 use crate::ln::features::InvoiceRequestFeatures;
  68 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
  69 use crate::ln::msgs::DecodeError;
  70 use crate::offers::invoice::{BlindedPayInfo, DerivedSigningPubkey, ExplicitSigningPubkey, InvoiceBuilder};
  71 use crate::offers::merkle::{SignError, SignatureTlvStream, SignatureTlvStreamRef, TaggedHash, self};
  72 use crate::offers::offer::{Offer, OfferContents, OfferTlvStream, OfferTlvStreamRef};
  73 use crate::offers::parse::{Bolt12ParseError, ParsedMessage, Bolt12SemanticError};
  74 use crate::offers::payer::{PayerContents, PayerTlvStream, PayerTlvStreamRef};
  75 use crate::offers::signer::{Metadata, MetadataMaterial};
  76 use crate::util::ser::{HighZeroBytesDroppedBigSize, SeekReadable, WithoutLength, Writeable, Writer};
  77 use crate::util::string::PrintableString;
  78
  79 use crate::prelude::*;
  80
  81 /// Tag for the hash function used when signing an [`InvoiceRequest`]'s merkle root.
  82 pub const SIGNATURE_TAG: &'static str = concat!("lightning", "invoice_request", "signature");
  83
  84 pub(super) const IV_BYTES: &[u8; IV_LEN] = b"LDK Invreq ~~~~~";
  85
  86 /// Builds an [`InvoiceRequest`] from an [`Offer`] for the "offer to be paid" flow.
  87 ///
  88 /// See [module-level documentation] for usage.
  89 ///
  90 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
  91 ///
  92 /// [module-level documentation]: self
  93 pub struct InvoiceRequestBuilder<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> {
  94         offer: &'a Offer,
  95         invoice_request: InvoiceRequestContentsWithoutPayerId,
  96         payer_id: Option<PublicKey>,
  97         payer_id_strategy: core::marker::PhantomData<P>,
  98         secp_ctx: Option<&'b Secp256k1<T>>,
  99 }
 100
 101 /// Indicates how [`InvoiceRequest::payer_id`] will be set.
 102 ///
 103 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 104 pub trait PayerIdStrategy {}
 105
 106 /// [`InvoiceRequest::payer_id`] will be explicitly set.
 107 ///
 108 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 109 pub struct ExplicitPayerId {}
 110
 111 /// [`InvoiceRequest::payer_id`] will be derived.
 112 ///
 113 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 114 pub struct DerivedPayerId {}
 115
 116 impl PayerIdStrategy for ExplicitPayerId {}
 117 impl PayerIdStrategy for DerivedPayerId {}
 118
 119 impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, ExplicitPayerId, T> {
 120         pub(super) fn new(offer: &'a Offer, metadata: Vec<u8>, payer_id: PublicKey) -> Self {
 121                 Self {
 122                         offer,
 123                         invoice_request: Self::create_contents(offer, Metadata::Bytes(metadata)),
 124                         payer_id: Some(payer_id),
 125                         payer_id_strategy: core::marker::PhantomData,
 126                         secp_ctx: None,
 127                 }
 128         }
 129
 130         pub(super) fn deriving_metadata<ES: Deref>(
 131                 offer: &'a Offer, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES
 132         ) -> Self where ES::Target: EntropySource {
 133                 let nonce = Nonce::from_entropy_source(entropy_source);
 134                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES);
 135                 let metadata = Metadata::Derived(derivation_material);
 136                 Self {
 137                         offer,
 138                         invoice_request: Self::create_contents(offer, metadata),
 139                         payer_id: Some(payer_id),
 140                         payer_id_strategy: core::marker::PhantomData,
 141                         secp_ctx: None,
 142                 }
 143         }
 144 }
 145
 146 impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T> {
 147         pub(super) fn deriving_payer_id<ES: Deref>(
 148                 offer: &'a Offer, expanded_key: &ExpandedKey, entropy_source: ES, secp_ctx: &'b Secp256k1<T>
 149         ) -> Self where ES::Target: EntropySource {
 150                 let nonce = Nonce::from_entropy_source(entropy_source);
 151                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES);
 152                 let metadata = Metadata::DerivedSigningPubkey(derivation_material);
 153                 Self {
 154                         offer,
 155                         invoice_request: Self::create_contents(offer, metadata),
 156                         payer_id: None,
 157                         payer_id_strategy: core::marker::PhantomData,
 158                         secp_ctx: Some(secp_ctx),
 159                 }
 160         }
 161 }
 162
 163 impl<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, P, T> {
 164         fn create_contents(offer: &Offer, metadata: Metadata) -> InvoiceRequestContentsWithoutPayerId {
 165                 let offer = offer.contents.clone();
 166                 InvoiceRequestContentsWithoutPayerId {
 167                         payer: PayerContents(metadata), offer, chain: None, amount_msats: None,
 168                         features: InvoiceRequestFeatures::empty(), quantity: None, payer_note: None,
 169                 }
 170         }
 171
 172         /// Sets the [`InvoiceRequest::chain`] of the given [`Network`] for paying an invoice. If not
 173         /// called, [`Network::Bitcoin`] is assumed. Errors if the chain for `network` is not supported
 174         /// by the offer.
 175         ///
 176         /// Successive calls to this method will override the previous setting.
 177         pub fn chain(mut self, network: Network) -> Result<Self, Bolt12SemanticError> {
 178                 let chain = ChainHash::using_genesis_block(network);
 179                 if !self.offer.supports_chain(chain) {
 180                         return Err(Bolt12SemanticError::UnsupportedChain);
 181                 }
 182
 183                 self.invoice_request.chain = Some(chain);
 184                 Ok(self)
 185         }
 186
 187         /// Sets the [`InvoiceRequest::amount_msats`] for paying an invoice. Errors if `amount_msats` is
 188         /// not at least the expected invoice amount (i.e., [`Offer::amount`] times [`quantity`]).
 189         ///
 190         /// Successive calls to this method will override the previous setting.
 191         ///
 192         /// [`quantity`]: Self::quantity
 193         pub fn amount_msats(mut self, amount_msats: u64) -> Result<Self, Bolt12SemanticError> {
 194                 self.invoice_request.offer.check_amount_msats_for_quantity(
 195                         Some(amount_msats), self.invoice_request.quantity
 196                 )?;
 197                 self.invoice_request.amount_msats = Some(amount_msats);
 198                 Ok(self)
 199         }
 200
 201         /// Sets [`InvoiceRequest::quantity`] of items. If not set, `1` is assumed. Errors if `quantity`
 202         /// does not conform to [`Offer::is_valid_quantity`].
 203         ///
 204         /// Successive calls to this method will override the previous setting.
 205         pub fn quantity(mut self, quantity: u64) -> Result<Self, Bolt12SemanticError> {
 206                 self.invoice_request.offer.check_quantity(Some(quantity))?;
 207                 self.invoice_request.quantity = Some(quantity);
 208                 Ok(self)
 209         }
 210
 211         /// Sets the [`InvoiceRequest::payer_note`].
 212         ///
 213         /// Successive calls to this method will override the previous setting.
 214         pub fn payer_note(mut self, payer_note: String) -> Self {
 215                 self.invoice_request.payer_note = Some(payer_note);
 216                 self
 217         }
 218
 219         fn build_with_checks(mut self) -> Result<
 220                 (UnsignedInvoiceRequest, Option<KeyPair>, Option<&'b Secp256k1<T>>),
 221                 Bolt12SemanticError
 222         > {
 223                 #[cfg(feature = "std")] {
 224                         if self.offer.is_expired() {
 225                                 return Err(Bolt12SemanticError::AlreadyExpired);
 226                         }
 227                 }
 228
 229                 let chain = self.invoice_request.chain();
 230                 if !self.offer.supports_chain(chain) {
 231                         return Err(Bolt12SemanticError::UnsupportedChain);
 232                 }
 233
 234                 if chain == self.offer.implied_chain() {
 235                         self.invoice_request.chain = None;
 236                 }
 237
 238                 if self.offer.amount().is_none() && self.invoice_request.amount_msats.is_none() {
 239                         return Err(Bolt12SemanticError::MissingAmount);
 240                 }
 241
 242                 self.invoice_request.offer.check_quantity(self.invoice_request.quantity)?;
 243                 self.invoice_request.offer.check_amount_msats_for_quantity(
 244                         self.invoice_request.amount_msats, self.invoice_request.quantity
 245                 )?;
 246
 247                 Ok(self.build_without_checks())
 248         }
 249
 250         fn build_without_checks(mut self) ->
 251                 (UnsignedInvoiceRequest, Option<KeyPair>, Option<&'b Secp256k1<T>>)
 252         {
 253                 // Create the metadata for stateless verification of a Bolt12Invoice.
 254                 let mut keys = None;
 255                 let secp_ctx = self.secp_ctx.clone();
 256                 if self.invoice_request.payer.0.has_derivation_material() {
 257                         let mut metadata = core::mem::take(&mut self.invoice_request.payer.0);
 258
 259                         let mut tlv_stream = self.invoice_request.as_tlv_stream();
 260                         debug_assert!(tlv_stream.2.payer_id.is_none());
 261                         tlv_stream.0.metadata = None;
 262                         if !metadata.derives_keys() {
 263                                 tlv_stream.2.payer_id = self.payer_id.as_ref();
 264                         }
 265
 266                         let (derived_metadata, derived_keys) = metadata.derive_from(tlv_stream, self.secp_ctx);
 267                         metadata = derived_metadata;
 268                         keys = derived_keys;
 269                         if let Some(keys) = keys {
 270                                 debug_assert!(self.payer_id.is_none());
 271                                 self.payer_id = Some(keys.public_key());
 272                         }
 273
 274                         self.invoice_request.payer.0 = metadata;
 275                 }
 276
 277                 debug_assert!(self.invoice_request.payer.0.as_bytes().is_some());
 278                 debug_assert!(self.payer_id.is_some());
 279                 let payer_id = self.payer_id.unwrap();
 280
 281                 let invoice_request = InvoiceRequestContents {
 282                         inner: self.invoice_request,
 283                         payer_id,
 284                 };
 285                 let unsigned_invoice_request = UnsignedInvoiceRequest::new(self.offer, invoice_request);
 286
 287                 (unsigned_invoice_request, keys, secp_ctx)
 288         }
 289 }
 290
 291 impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, ExplicitPayerId, T> {
 292         /// Builds an unsigned [`InvoiceRequest`] after checking for valid semantics. It can be signed
 293         /// by [`UnsignedInvoiceRequest::sign`].
 294         pub fn build(self) -> Result<UnsignedInvoiceRequest, Bolt12SemanticError> {
 295                 let (unsigned_invoice_request, keys, _) = self.build_with_checks()?;
 296                 debug_assert!(keys.is_none());
 297                 Ok(unsigned_invoice_request)
 298         }
 299 }
 300
 301 impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T> {
 302         /// Builds a signed [`InvoiceRequest`] after checking for valid semantics.
 303         pub fn build_and_sign(self) -> Result<InvoiceRequest, Bolt12SemanticError> {
 304                 let (unsigned_invoice_request, keys, secp_ctx) = self.build_with_checks()?;
 305                 debug_assert!(keys.is_some());
 306
 307                 let secp_ctx = secp_ctx.unwrap();
 308                 let keys = keys.unwrap();
 309                 let invoice_request = unsigned_invoice_request
 310                         .sign::<_, Infallible>(
 311                                 |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
 312                         )
 313                         .unwrap();
 314                 Ok(invoice_request)
 315         }
 316 }
 317
 318 #[cfg(test)]
 319 impl<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, P, T> {
 320         fn chain_unchecked(mut self, network: Network) -> Self {
 321                 let chain = ChainHash::using_genesis_block(network);
 322                 self.invoice_request.chain = Some(chain);
 323                 self
 324         }
 325
 326         fn amount_msats_unchecked(mut self, amount_msats: u64) -> Self {
 327                 self.invoice_request.amount_msats = Some(amount_msats);
 328                 self
 329         }
 330
 331         fn features_unchecked(mut self, features: InvoiceRequestFeatures) -> Self {
 332                 self.invoice_request.features = features;
 333                 self
 334         }
 335
 336         fn quantity_unchecked(mut self, quantity: u64) -> Self {
 337                 self.invoice_request.quantity = Some(quantity);
 338                 self
 339         }
 340
 341         pub(super) fn build_unchecked(self) -> UnsignedInvoiceRequest {
 342                 self.build_without_checks().0
 343         }
 344 }
 345
 346 /// A semantically valid [`InvoiceRequest`] that hasn't been signed.
 347 ///
 348 /// # Serialization
 349 ///
 350 /// This is serialized as a TLV stream, which includes TLV records from the originating message. As
 351 /// such, it may include unknown, odd TLV records.
 352 pub struct UnsignedInvoiceRequest {
 353         bytes: Vec<u8>,
 354         contents: InvoiceRequestContents,
 355         tagged_hash: TaggedHash,
 356 }
 357
 358 impl UnsignedInvoiceRequest {
 359         fn new(offer: &Offer, contents: InvoiceRequestContents) -> Self {
 360                 // Use the offer bytes instead of the offer TLV stream as the offer may have contained
 361                 // unknown TLV records, which are not stored in `OfferContents`.
 362                 let (payer_tlv_stream, _offer_tlv_stream, invoice_request_tlv_stream) =
 363                         contents.as_tlv_stream();
 364                 let offer_bytes = WithoutLength(&offer.bytes);
 365                 let unsigned_tlv_stream = (payer_tlv_stream, offer_bytes, invoice_request_tlv_stream);
 366
 367                 let mut bytes = Vec::new();
 368                 unsigned_tlv_stream.write(&mut bytes).unwrap();
 369
 370                 let tagged_hash = TaggedHash::new(SIGNATURE_TAG, &bytes);
 371
 372                 Self { bytes, contents, tagged_hash }
 373         }
 374
 375         /// Signs the [`TaggedHash`] of the invoice request using the given function.
 376         ///
 377         /// Note: The hash computation may have included unknown, odd TLV records.
 378         ///
 379         /// This is not exported to bindings users as functions are not yet mapped.
 380         pub fn sign<F, E>(mut self, sign: F) -> Result<InvoiceRequest, SignError<E>>
 381         where
 382                 F: FnOnce(&Self) -> Result<Signature, E>
 383         {
 384                 let pubkey = self.contents.payer_id;
 385                 let signature = merkle::sign_message(sign, &self, pubkey)?;
 386
 387                 // Append the signature TLV record to the bytes.
 388                 let signature_tlv_stream = SignatureTlvStreamRef {
 389                         signature: Some(&signature),
 390                 };
 391                 signature_tlv_stream.write(&mut self.bytes).unwrap();
 392
 393                 Ok(InvoiceRequest {
 394                         bytes: self.bytes,
 395                         contents: self.contents,
 396                         signature,
 397                 })
 398         }
 399 }
 400
 401 impl AsRef<TaggedHash> for UnsignedInvoiceRequest {
 402         fn as_ref(&self) -> &TaggedHash {
 403                 &self.tagged_hash
 404         }
 405 }
 406
 407 /// An `InvoiceRequest` is a request for a [`Bolt12Invoice`] formulated from an [`Offer`].
 408 ///
 409 /// An offer may provide choices such as quantity, amount, chain, features, etc. An invoice request
 410 /// specifies these such that its recipient can send an invoice for payment.
 411 ///
 412 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 413 /// [`Offer`]: crate::offers::offer::Offer
 414 #[derive(Clone, Debug)]
 415 #[cfg_attr(test, derive(PartialEq))]
 416 pub struct InvoiceRequest {
 417         pub(super) bytes: Vec<u8>,
 418         pub(super) contents: InvoiceRequestContents,
 419         signature: Signature,
 420 }
 421
 422 /// The contents of an [`InvoiceRequest`], which may be shared with an [`Bolt12Invoice`].
 423 ///
 424 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 425 #[derive(Clone, Debug)]
 426 #[cfg_attr(test, derive(PartialEq))]
 427 pub(super) struct InvoiceRequestContents {
 428         pub(super) inner: InvoiceRequestContentsWithoutPayerId,
 429         payer_id: PublicKey,
 430 }
 431
 432 #[derive(Clone, Debug)]
 433 #[cfg_attr(test, derive(PartialEq))]
 434 pub(super) struct InvoiceRequestContentsWithoutPayerId {
 435         payer: PayerContents,
 436         pub(super) offer: OfferContents,
 437         chain: Option<ChainHash>,
 438         amount_msats: Option<u64>,
 439         features: InvoiceRequestFeatures,
 440         quantity: Option<u64>,
 441         payer_note: Option<String>,
 442 }
 443
 444 macro_rules! invoice_request_accessors { ($self: ident, $contents: expr) => {
 445         /// An unpredictable series of bytes, typically containing information about the derivation of
 446         /// [`payer_id`].
 447         ///
 448         /// [`payer_id`]: Self::payer_id
 449         pub fn payer_metadata(&$self) -> &[u8] {
 450                 $contents.metadata()
 451         }
 452
 453         /// A chain from [`Offer::chains`] that the offer is valid for.
 454         pub fn chain(&$self) -> ChainHash {
 455                 $contents.chain()
 456         }
 457
 458         /// The amount to pay in msats (i.e., the minimum lightning-payable unit for [`chain`]), which
 459         /// must be greater than or equal to [`Offer::amount`], converted if necessary.
 460         ///
 461         /// [`chain`]: Self::chain
 462         pub fn amount_msats(&$self) -> Option<u64> {
 463                 $contents.amount_msats()
 464         }
 465
 466         /// Features pertaining to requesting an invoice.
 467         pub fn invoice_request_features(&$self) -> &InvoiceRequestFeatures {
 468                 &$contents.features()
 469         }
 470
 471         /// The quantity of the offer's item conforming to [`Offer::is_valid_quantity`].
 472         pub fn quantity(&$self) -> Option<u64> {
 473                 $contents.quantity()
 474         }
 475
 476         /// A possibly transient pubkey used to sign the invoice request.
 477         pub fn payer_id(&$self) -> PublicKey {
 478                 $contents.payer_id()
 479         }
 480
 481         /// A payer-provided note which will be seen by the recipient and reflected back in the invoice
 482         /// response.
 483         pub fn payer_note(&$self) -> Option<PrintableString> {
 484                 $contents.payer_note()
 485         }
 486 } }
 487
 488 impl InvoiceRequest {
 489         invoice_request_accessors!(self, self.contents);
 490
 491         /// Signature of the invoice request using [`payer_id`].
 492         ///
 493         /// [`payer_id`]: Self::payer_id
 494         pub fn signature(&self) -> Signature {
 495                 self.signature
 496         }
 497
 498         /// Creates an [`InvoiceBuilder`] for the request with the given required fields and using the
 499         /// [`Duration`] since [`std::time::SystemTime::UNIX_EPOCH`] as the creation time.
 500         ///
 501         /// See [`InvoiceRequest::respond_with_no_std`] for further details where the aforementioned
 502         /// creation time is used for the `created_at` parameter.
 503         ///
 504         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 505         ///
 506         /// [`Duration`]: core::time::Duration
 507         #[cfg(feature = "std")]
 508         pub fn respond_with(
 509                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash
 510         ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, Bolt12SemanticError> {
 511                 let created_at = std::time::SystemTime::now()
 512                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 513                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 514
 515                 self.respond_with_no_std(payment_paths, payment_hash, created_at)
 516         }
 517
 518         /// Creates an [`InvoiceBuilder`] for the request with the given required fields.
 519         ///
 520         /// Unless [`InvoiceBuilder::relative_expiry`] is set, the invoice will expire two hours after
 521         /// `created_at`, which is used to set [`Bolt12Invoice::created_at`]. Useful for `no-std` builds
 522         /// where [`std::time::SystemTime`] is not available.
 523         ///
 524         /// The caller is expected to remember the preimage of `payment_hash` in order to claim a payment
 525         /// for the invoice.
 526         ///
 527         /// The `payment_paths` parameter is useful for maintaining the payment recipient's privacy. It
 528         /// must contain one or more elements ordered from most-preferred to least-preferred, if there's
 529         /// a preference. Note, however, that any privacy is lost if a public node id was used for
 530         /// [`Offer::signing_pubkey`].
 531         ///
 532         /// Errors if the request contains unknown required features.
 533         ///
 534         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 535         ///
 536         /// [`Bolt12Invoice::created_at`]: crate::offers::invoice::Bolt12Invoice::created_at
 537         pub fn respond_with_no_std(
 538                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 539                 created_at: core::time::Duration
 540         ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, Bolt12SemanticError> {
 541                 if self.invoice_request_features().requires_unknown_bits() {
 542                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 543                 }
 544
 545                 InvoiceBuilder::for_offer(self, payment_paths, created_at, payment_hash)
 546         }
 547
 548         /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
 549         /// derived signing keys from the originating [`Offer`] to sign the [`Bolt12Invoice`]. Must use
 550         /// the same [`ExpandedKey`] as the one used to create the offer.
 551         ///
 552         /// See [`InvoiceRequest::respond_with`] for further details.
 553         ///
 554         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 555         ///
 556         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 557         #[cfg(feature = "std")]
 558         pub fn verify_and_respond_using_derived_keys<T: secp256k1::Signing>(
 559                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 560                 expanded_key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 561         ) -> Result<InvoiceBuilder<DerivedSigningPubkey>, Bolt12SemanticError> {
 562                 let created_at = std::time::SystemTime::now()
 563                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 564                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 565
 566                 self.verify_and_respond_using_derived_keys_no_std(
 567                         payment_paths, payment_hash, created_at, expanded_key, secp_ctx
 568                 )
 569         }
 570
 571         /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
 572         /// derived signing keys from the originating [`Offer`] to sign the [`Bolt12Invoice`]. Must use
 573         /// the same [`ExpandedKey`] as the one used to create the offer.
 574         ///
 575         /// See [`InvoiceRequest::respond_with_no_std`] for further details.
 576         ///
 577         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 578         ///
 579         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 580         pub fn verify_and_respond_using_derived_keys_no_std<T: secp256k1::Signing>(
 581                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 582                 created_at: core::time::Duration, expanded_key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 583         ) -> Result<InvoiceBuilder<DerivedSigningPubkey>, Bolt12SemanticError> {
 584                 if self.invoice_request_features().requires_unknown_bits() {
 585                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 586                 }
 587
 588                 let keys = match self.verify(expanded_key, secp_ctx) {
 589                         Err(()) => return Err(Bolt12SemanticError::InvalidMetadata),
 590                         Ok(None) => return Err(Bolt12SemanticError::InvalidMetadata),
 591                         Ok(Some(keys)) => keys,
 592                 };
 593
 594                 InvoiceBuilder::for_offer_using_keys(self, payment_paths, created_at, payment_hash, keys)
 595         }
 596
 597         /// Verifies that the request was for an offer created using the given key. Returns the derived
 598         /// keys need to sign an [`Bolt12Invoice`] for the request if they could be extracted from the
 599         /// metadata.
 600         ///
 601         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 602         pub fn verify<T: secp256k1::Signing>(
 603                 &self, key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 604         ) -> Result<Option<KeyPair>, ()> {
 605                 self.contents.inner.offer.verify(&self.bytes, key, secp_ctx)
 606         }
 607
 608         #[cfg(test)]
 609         fn as_tlv_stream(&self) -> FullInvoiceRequestTlvStreamRef {
 610                 let (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream) =
 611                         self.contents.as_tlv_stream();
 612                 let signature_tlv_stream = SignatureTlvStreamRef {
 613                         signature: Some(&self.signature),
 614                 };
 615                 (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, signature_tlv_stream)
 616         }
 617 }
 618
 619 impl InvoiceRequestContents {
 620         pub(super) fn metadata(&self) -> &[u8] {
 621                 self.inner.metadata()
 622         }
 623
 624         pub(super) fn derives_keys(&self) -> bool {
 625                 self.inner.payer.0.derives_keys()
 626         }
 627
 628         pub(super) fn chain(&self) -> ChainHash {
 629                 self.inner.chain()
 630         }
 631
 632         fn amount_msats(&self) -> Option<u64> {
 633                 self.inner.amount_msats
 634         }
 635
 636         fn features(&self) -> &InvoiceRequestFeatures {
 637                 &self.inner.features
 638         }
 639
 640         fn quantity(&self) -> Option<u64> {
 641                 self.inner.quantity
 642         }
 643
 644         pub(super) fn payer_id(&self) -> PublicKey {
 645                 self.payer_id
 646         }
 647
 648         fn payer_note(&self) -> Option<PrintableString> {
 649                 self.inner.payer_note.as_ref()
 650                         .map(|payer_note| PrintableString(payer_note.as_str()))
 651         }
 652
 653         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 654                 let (payer, offer, mut invoice_request) = self.inner.as_tlv_stream();
 655                 invoice_request.payer_id = Some(&self.payer_id);
 656                 (payer, offer, invoice_request)
 657         }
 658 }
 659
 660 impl InvoiceRequestContentsWithoutPayerId {
 661         pub(super) fn metadata(&self) -> &[u8] {
 662                 self.payer.0.as_bytes().map(|bytes| bytes.as_slice()).unwrap_or(&[])
 663         }
 664
 665         pub(super) fn chain(&self) -> ChainHash {
 666                 self.chain.unwrap_or_else(|| self.offer.implied_chain())
 667         }
 668
 669         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 670                 let payer = PayerTlvStreamRef {
 671                         metadata: self.payer.0.as_bytes(),
 672                 };
 673
 674                 let offer = self.offer.as_tlv_stream();
 675
 676                 let features = {
 677                         if self.features == InvoiceRequestFeatures::empty() { None }
 678                         else { Some(&self.features) }
 679                 };
 680
 681                 let invoice_request = InvoiceRequestTlvStreamRef {
 682                         chain: self.chain.as_ref(),
 683                         amount: self.amount_msats,
 684                         features,
 685                         quantity: self.quantity,
 686                         payer_id: None,
 687                         payer_note: self.payer_note.as_ref(),
 688                 };
 689
 690                 (payer, offer, invoice_request)
 691         }
 692 }
 693
 694 impl Writeable for UnsignedInvoiceRequest {
 695         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 696                 WithoutLength(&self.bytes).write(writer)
 697         }
 698 }
 699
 700 impl Writeable for InvoiceRequest {
 701         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 702                 WithoutLength(&self.bytes).write(writer)
 703         }
 704 }
 705
 706 impl Writeable for InvoiceRequestContents {
 707         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 708                 self.as_tlv_stream().write(writer)
 709         }
 710 }
 711
 712 /// Valid type range for invoice_request TLV records.
 713 pub(super) const INVOICE_REQUEST_TYPES: core::ops::Range<u64> = 80..160;
 714
 715 /// TLV record type for [`InvoiceRequest::payer_id`] and [`Refund::payer_id`].
 716 ///
 717 /// [`Refund::payer_id`]: crate::offers::refund::Refund::payer_id
 718 pub(super) const INVOICE_REQUEST_PAYER_ID_TYPE: u64 = 88;
 719
 720 tlv_stream!(InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef, INVOICE_REQUEST_TYPES, {
 721         (80, chain: ChainHash),
 722         (82, amount: (u64, HighZeroBytesDroppedBigSize)),
 723         (84, features: (InvoiceRequestFeatures, WithoutLength)),
 724         (86, quantity: (u64, HighZeroBytesDroppedBigSize)),
 725         (INVOICE_REQUEST_PAYER_ID_TYPE, payer_id: PublicKey),
 726         (89, payer_note: (String, WithoutLength)),
 727 });
 728
 729 type FullInvoiceRequestTlvStream =
 730         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, SignatureTlvStream);
 731
 732 #[cfg(test)]
 733 type FullInvoiceRequestTlvStreamRef<'a> = (
 734         PayerTlvStreamRef<'a>,
 735         OfferTlvStreamRef<'a>,
 736         InvoiceRequestTlvStreamRef<'a>,
 737         SignatureTlvStreamRef<'a>,
 738 );
 739
 740 impl SeekReadable for FullInvoiceRequestTlvStream {
 741         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 742                 let payer = SeekReadable::read(r)?;
 743                 let offer = SeekReadable::read(r)?;
 744                 let invoice_request = SeekReadable::read(r)?;
 745                 let signature = SeekReadable::read(r)?;
 746
 747                 Ok((payer, offer, invoice_request, signature))
 748         }
 749 }
 750
 751 type PartialInvoiceRequestTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
 752
 753 type PartialInvoiceRequestTlvStreamRef<'a> = (
 754         PayerTlvStreamRef<'a>,
 755         OfferTlvStreamRef<'a>,
 756         InvoiceRequestTlvStreamRef<'a>,
 757 );
 758
 759 impl TryFrom<Vec<u8>> for UnsignedInvoiceRequest {
 760         type Error = Bolt12ParseError;
 761
 762         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 763                 let invoice_request = ParsedMessage::<PartialInvoiceRequestTlvStream>::try_from(bytes)?;
 764                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
 765                 let (
 766                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
 767                 ) = tlv_stream;
 768                 let contents = InvoiceRequestContents::try_from(
 769                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 770                 )?;
 771
 772                 let tagged_hash = TaggedHash::new(SIGNATURE_TAG, &bytes);
 773
 774                 Ok(UnsignedInvoiceRequest { bytes, contents, tagged_hash })
 775         }
 776 }
 777
 778 impl TryFrom<Vec<u8>> for InvoiceRequest {
 779         type Error = Bolt12ParseError;
 780
 781         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 782                 let invoice_request = ParsedMessage::<FullInvoiceRequestTlvStream>::try_from(bytes)?;
 783                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
 784                 let (
 785                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
 786                         SignatureTlvStream { signature },
 787                 ) = tlv_stream;
 788                 let contents = InvoiceRequestContents::try_from(
 789                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 790                 )?;
 791
 792                 let signature = match signature {
 793                         None => return Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
 794                         Some(signature) => signature,
 795                 };
 796                 merkle::verify_signature(&signature, SIGNATURE_TAG, &bytes, contents.payer_id)?;
 797
 798                 Ok(InvoiceRequest { bytes, contents, signature })
 799         }
 800 }
 801
 802 impl TryFrom<PartialInvoiceRequestTlvStream> for InvoiceRequestContents {
 803         type Error = Bolt12SemanticError;
 804
 805         fn try_from(tlv_stream: PartialInvoiceRequestTlvStream) -> Result<Self, Self::Error> {
 806                 let (
 807                         PayerTlvStream { metadata },
 808                         offer_tlv_stream,
 809                         InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
 810                 ) = tlv_stream;
 811
 812                 let payer = match metadata {
 813                         None => return Err(Bolt12SemanticError::MissingPayerMetadata),
 814                         Some(metadata) => PayerContents(Metadata::Bytes(metadata)),
 815                 };
 816                 let offer = OfferContents::try_from(offer_tlv_stream)?;
 817
 818                 if !offer.supports_chain(chain.unwrap_or_else(|| offer.implied_chain())) {
 819                         return Err(Bolt12SemanticError::UnsupportedChain);
 820                 }
 821
 822                 if offer.amount().is_none() && amount.is_none() {
 823                         return Err(Bolt12SemanticError::MissingAmount);
 824                 }
 825
 826                 offer.check_quantity(quantity)?;
 827                 offer.check_amount_msats_for_quantity(amount, quantity)?;
 828
 829                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
 830
 831                 let payer_id = match payer_id {
 832                         None => return Err(Bolt12SemanticError::MissingPayerId),
 833                         Some(payer_id) => payer_id,
 834                 };
 835
 836                 Ok(InvoiceRequestContents {
 837                         inner: InvoiceRequestContentsWithoutPayerId {
 838                                 payer, offer, chain, amount_msats: amount, features, quantity, payer_note,
 839                         },
 840                         payer_id,
 841                 })
 842         }
 843 }
 844
 845 #[cfg(test)]
 846 mod tests {
 847         use super::{InvoiceRequest, InvoiceRequestTlvStreamRef, SIGNATURE_TAG, UnsignedInvoiceRequest};
 848
 849         use bitcoin::blockdata::constants::ChainHash;
 850         use bitcoin::network::constants::Network;
 851         use bitcoin::secp256k1::{KeyPair, Secp256k1, SecretKey, self};
 852         use core::convert::{Infallible, TryFrom};
 853         use core::num::NonZeroU64;
 854         #[cfg(feature = "std")]
 855         use core::time::Duration;
 856         use crate::sign::KeyMaterial;
 857         use crate::ln::features::InvoiceRequestFeatures;
 858         use crate::ln::inbound_payment::ExpandedKey;
 859         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 860         use crate::offers::invoice::{Bolt12Invoice, SIGNATURE_TAG as INVOICE_SIGNATURE_TAG};
 861         use crate::offers::merkle::{SignError, SignatureTlvStreamRef, TaggedHash, self};
 862         use crate::offers::offer::{Amount, OfferBuilder, OfferTlvStreamRef, Quantity};
 863         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
 864         use crate::offers::payer::PayerTlvStreamRef;
 865         use crate::offers::test_utils::*;
 866         use crate::util::ser::{BigSize, Writeable};
 867         use crate::util::string::PrintableString;
 868
 869         #[test]
 870         fn builds_invoice_request_with_defaults() {
 871                 let unsigned_invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 872                         .amount_msats(1000)
 873                         .build().unwrap()
 874                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 875                         .build().unwrap();
 876
 877                 let mut buffer = Vec::new();
 878                 unsigned_invoice_request.write(&mut buffer).unwrap();
 879
 880                 match UnsignedInvoiceRequest::try_from(buffer) {
 881                         Err(e) => panic!("error parsing unsigned invoice request: {:?}", e),
 882                         Ok(parsed) => {
 883                                 assert_eq!(parsed.bytes, unsigned_invoice_request.bytes);
 884                                 assert_eq!(parsed.tagged_hash, unsigned_invoice_request.tagged_hash);
 885                         },
 886                 }
 887
 888                 let invoice_request = unsigned_invoice_request.sign(payer_sign).unwrap();
 889
 890                 let mut buffer = Vec::new();
 891                 invoice_request.write(&mut buffer).unwrap();
 892
 893                 assert_eq!(invoice_request.bytes, buffer.as_slice());
 894                 assert_eq!(invoice_request.payer_metadata(), &[1; 32]);
 895                 assert_eq!(invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
 896                 assert_eq!(invoice_request.amount_msats(), None);
 897                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
 898                 assert_eq!(invoice_request.quantity(), None);
 899                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
 900                 assert_eq!(invoice_request.payer_note(), None);
 901                 assert!(
 902                         merkle::verify_signature(
 903                                 &invoice_request.signature, SIGNATURE_TAG, &invoice_request.bytes, payer_pubkey()
 904                         ).is_ok()
 905                 );
 906
 907                 assert_eq!(
 908                         invoice_request.as_tlv_stream(),
 909                         (
 910                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
 911                                 OfferTlvStreamRef {
 912                                         chains: None,
 913                                         metadata: None,
 914                                         currency: None,
 915                                         amount: Some(1000),
 916                                         description: Some(&String::from("foo")),
 917                                         features: None,
 918                                         absolute_expiry: None,
 919                                         paths: None,
 920                                         issuer: None,
 921                                         quantity_max: None,
 922                                         node_id: Some(&recipient_pubkey()),
 923                                 },
 924                                 InvoiceRequestTlvStreamRef {
 925                                         chain: None,
 926                                         amount: None,
 927                                         features: None,
 928                                         quantity: None,
 929                                         payer_id: Some(&payer_pubkey()),
 930                                         payer_note: None,
 931                                 },
 932                                 SignatureTlvStreamRef { signature: Some(&invoice_request.signature()) },
 933                         ),
 934                 );
 935
 936                 if let Err(e) = InvoiceRequest::try_from(buffer) {
 937                         panic!("error parsing invoice request: {:?}", e);
 938                 }
 939         }
 940
 941         #[cfg(feature = "std")]
 942         #[test]
 943         fn builds_invoice_request_from_offer_with_expiration() {
 944                 let future_expiry = Duration::from_secs(u64::max_value());
 945                 let past_expiry = Duration::from_secs(0);
 946
 947                 if let Err(e) = OfferBuilder::new("foo".into(), recipient_pubkey())
 948                         .amount_msats(1000)
 949                         .absolute_expiry(future_expiry)
 950                         .build().unwrap()
 951                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 952                         .build()
 953                 {
 954                         panic!("error building invoice_request: {:?}", e);
 955                 }
 956
 957                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 958                         .amount_msats(1000)
 959                         .absolute_expiry(past_expiry)
 960                         .build().unwrap()
 961                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 962                         .build()
 963                 {
 964                         Ok(_) => panic!("expected error"),
 965                         Err(e) => assert_eq!(e, Bolt12SemanticError::AlreadyExpired),
 966                 }
 967         }
 968
 969         #[test]
 970         fn builds_invoice_request_with_derived_metadata() {
 971                 let payer_id = payer_pubkey();
 972                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
 973                 let entropy = FixedEntropy {};
 974                 let secp_ctx = Secp256k1::new();
 975
 976                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
 977                         .amount_msats(1000)
 978                         .build().unwrap();
 979                 let invoice_request = offer
 980                         .request_invoice_deriving_metadata(payer_id, &expanded_key, &entropy)
 981                         .unwrap()
 982                         .build().unwrap()
 983                         .sign(payer_sign).unwrap();
 984                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
 985
 986                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
 987                         .unwrap()
 988                         .build().unwrap()
 989                         .sign(recipient_sign).unwrap();
 990                 assert!(invoice.verify(&expanded_key, &secp_ctx));
 991
 992                 // Fails verification with altered fields
 993                 let (
 994                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
 995                         mut invoice_tlv_stream, mut signature_tlv_stream
 996                 ) = invoice.as_tlv_stream();
 997                 invoice_request_tlv_stream.amount = Some(2000);
 998                 invoice_tlv_stream.amount = Some(2000);
 999
1000                 let tlv_stream =
1001                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1002                 let mut bytes = Vec::new();
1003                 tlv_stream.write(&mut bytes).unwrap();
1004
1005                 let message = TaggedHash::new(INVOICE_SIGNATURE_TAG, &bytes);
1006                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1007                 signature_tlv_stream.signature = Some(&signature);
1008
1009                 let mut encoded_invoice = bytes;
1010                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1011
1012                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1013                 assert!(!invoice.verify(&expanded_key, &secp_ctx));
1014
1015                 // Fails verification with altered metadata
1016                 let (
1017                         mut payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
1018                         mut signature_tlv_stream
1019                 ) = invoice.as_tlv_stream();
1020                 let metadata = payer_tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1021                 payer_tlv_stream.metadata = Some(&metadata);
1022
1023                 let tlv_stream =
1024                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1025                 let mut bytes = Vec::new();
1026                 tlv_stream.write(&mut bytes).unwrap();
1027
1028                 let message = TaggedHash::new(INVOICE_SIGNATURE_TAG, &bytes);
1029                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1030                 signature_tlv_stream.signature = Some(&signature);
1031
1032                 let mut encoded_invoice = bytes;
1033                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1034
1035                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1036                 assert!(!invoice.verify(&expanded_key, &secp_ctx));
1037         }
1038
1039         #[test]
1040         fn builds_invoice_request_with_derived_payer_id() {
1041                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1042                 let entropy = FixedEntropy {};
1043                 let secp_ctx = Secp256k1::new();
1044
1045                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1046                         .amount_msats(1000)
1047                         .build().unwrap();
1048                 let invoice_request = offer
1049                         .request_invoice_deriving_payer_id(&expanded_key, &entropy, &secp_ctx)
1050                         .unwrap()
1051                         .build_and_sign()
1052                         .unwrap();
1053
1054                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
1055                         .unwrap()
1056                         .build().unwrap()
1057                         .sign(recipient_sign).unwrap();
1058                 assert!(invoice.verify(&expanded_key, &secp_ctx));
1059
1060                 // Fails verification with altered fields
1061                 let (
1062                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
1063                         mut invoice_tlv_stream, mut signature_tlv_stream
1064                 ) = invoice.as_tlv_stream();
1065                 invoice_request_tlv_stream.amount = Some(2000);
1066                 invoice_tlv_stream.amount = Some(2000);
1067
1068                 let tlv_stream =
1069                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1070                 let mut bytes = Vec::new();
1071                 tlv_stream.write(&mut bytes).unwrap();
1072
1073                 let message = TaggedHash::new(INVOICE_SIGNATURE_TAG, &bytes);
1074                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1075                 signature_tlv_stream.signature = Some(&signature);
1076
1077                 let mut encoded_invoice = bytes;
1078                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1079
1080                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1081                 assert!(!invoice.verify(&expanded_key, &secp_ctx));
1082
1083                 // Fails verification with altered payer id
1084                 let (
1085                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream, invoice_tlv_stream,
1086                         mut signature_tlv_stream
1087                 ) = invoice.as_tlv_stream();
1088                 let payer_id = pubkey(1);
1089                 invoice_request_tlv_stream.payer_id = Some(&payer_id);
1090
1091                 let tlv_stream =
1092                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1093                 let mut bytes = Vec::new();
1094                 tlv_stream.write(&mut bytes).unwrap();
1095
1096                 let message = TaggedHash::new(INVOICE_SIGNATURE_TAG, &bytes);
1097                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1098                 signature_tlv_stream.signature = Some(&signature);
1099
1100                 let mut encoded_invoice = bytes;
1101                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1102
1103                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1104                 assert!(!invoice.verify(&expanded_key, &secp_ctx));
1105         }
1106
1107         #[test]
1108         fn builds_invoice_request_with_chain() {
1109                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
1110                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
1111
1112                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1113                         .amount_msats(1000)
1114                         .build().unwrap()
1115                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1116                         .chain(Network::Bitcoin).unwrap()
1117                         .build().unwrap()
1118                         .sign(payer_sign).unwrap();
1119                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1120                 assert_eq!(invoice_request.chain(), mainnet);
1121                 assert_eq!(tlv_stream.chain, None);
1122
1123                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1124                         .amount_msats(1000)
1125                         .chain(Network::Testnet)
1126                         .build().unwrap()
1127                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1128                         .chain(Network::Testnet).unwrap()
1129                         .build().unwrap()
1130                         .sign(payer_sign).unwrap();
1131                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1132                 assert_eq!(invoice_request.chain(), testnet);
1133                 assert_eq!(tlv_stream.chain, Some(&testnet));
1134
1135                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1136                         .amount_msats(1000)
1137                         .chain(Network::Bitcoin)
1138                         .chain(Network::Testnet)
1139                         .build().unwrap()
1140                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1141                         .chain(Network::Bitcoin).unwrap()
1142                         .build().unwrap()
1143                         .sign(payer_sign).unwrap();
1144                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1145                 assert_eq!(invoice_request.chain(), mainnet);
1146                 assert_eq!(tlv_stream.chain, None);
1147
1148                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1149                         .amount_msats(1000)
1150                         .chain(Network::Bitcoin)
1151                         .chain(Network::Testnet)
1152                         .build().unwrap()
1153                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1154                         .chain(Network::Bitcoin).unwrap()
1155                         .chain(Network::Testnet).unwrap()
1156                         .build().unwrap()
1157                         .sign(payer_sign).unwrap();
1158                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1159                 assert_eq!(invoice_request.chain(), testnet);
1160                 assert_eq!(tlv_stream.chain, Some(&testnet));
1161
1162                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1163                         .amount_msats(1000)
1164                         .chain(Network::Testnet)
1165                         .build().unwrap()
1166                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1167                         .chain(Network::Bitcoin)
1168                 {
1169                         Ok(_) => panic!("expected error"),
1170                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
1171                 }
1172
1173                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1174                         .amount_msats(1000)
1175                         .chain(Network::Testnet)
1176                         .build().unwrap()
1177                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1178                         .build()
1179                 {
1180                         Ok(_) => panic!("expected error"),
1181                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
1182                 }
1183         }
1184
1185         #[test]
1186         fn builds_invoice_request_with_amount() {
1187                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1188                         .amount_msats(1000)
1189                         .build().unwrap()
1190                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1191                         .amount_msats(1000).unwrap()
1192                         .build().unwrap()
1193                         .sign(payer_sign).unwrap();
1194                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1195                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1196                 assert_eq!(tlv_stream.amount, Some(1000));
1197
1198                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1199                         .amount_msats(1000)
1200                         .build().unwrap()
1201                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1202                         .amount_msats(1001).unwrap()
1203                         .amount_msats(1000).unwrap()
1204                         .build().unwrap()
1205                         .sign(payer_sign).unwrap();
1206                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1207                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1208                 assert_eq!(tlv_stream.amount, Some(1000));
1209
1210                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1211                         .amount_msats(1000)
1212                         .build().unwrap()
1213                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1214                         .amount_msats(1001).unwrap()
1215                         .build().unwrap()
1216                         .sign(payer_sign).unwrap();
1217                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1218                 assert_eq!(invoice_request.amount_msats(), Some(1001));
1219                 assert_eq!(tlv_stream.amount, Some(1001));
1220
1221                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1222                         .amount_msats(1000)
1223                         .build().unwrap()
1224                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1225                         .amount_msats(999)
1226                 {
1227                         Ok(_) => panic!("expected error"),
1228                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1229                 }
1230
1231                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1232                         .amount_msats(1000)
1233                         .supported_quantity(Quantity::Unbounded)
1234                         .build().unwrap()
1235                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1236                         .quantity(2).unwrap()
1237                         .amount_msats(1000)
1238                 {
1239                         Ok(_) => panic!("expected error"),
1240                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1241                 }
1242
1243                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1244                         .amount_msats(1000)
1245                         .build().unwrap()
1246                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1247                         .amount_msats(MAX_VALUE_MSAT + 1)
1248                 {
1249                         Ok(_) => panic!("expected error"),
1250                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1251                 }
1252
1253                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1254                         .amount_msats(1000)
1255                         .supported_quantity(Quantity::Unbounded)
1256                         .build().unwrap()
1257                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1258                         .amount_msats(1000).unwrap()
1259                         .quantity(2).unwrap()
1260                         .build()
1261                 {
1262                         Ok(_) => panic!("expected error"),
1263                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1264                 }
1265
1266                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1267                         .build().unwrap()
1268                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1269                         .build()
1270                 {
1271                         Ok(_) => panic!("expected error"),
1272                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingAmount),
1273                 }
1274
1275                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1276                         .amount_msats(1000)
1277                         .supported_quantity(Quantity::Unbounded)
1278                         .build().unwrap()
1279                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1280                         .quantity(u64::max_value()).unwrap()
1281                         .build()
1282                 {
1283                         Ok(_) => panic!("expected error"),
1284                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1285                 }
1286         }
1287
1288         #[test]
1289         fn builds_invoice_request_with_features() {
1290                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1291                         .amount_msats(1000)
1292                         .build().unwrap()
1293                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1294                         .features_unchecked(InvoiceRequestFeatures::unknown())
1295                         .build().unwrap()
1296                         .sign(payer_sign).unwrap();
1297                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1298                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::unknown());
1299                 assert_eq!(tlv_stream.features, Some(&InvoiceRequestFeatures::unknown()));
1300
1301                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1302                         .amount_msats(1000)
1303                         .build().unwrap()
1304                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1305                         .features_unchecked(InvoiceRequestFeatures::unknown())
1306                         .features_unchecked(InvoiceRequestFeatures::empty())
1307                         .build().unwrap()
1308                         .sign(payer_sign).unwrap();
1309                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1310                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
1311                 assert_eq!(tlv_stream.features, None);
1312         }
1313
1314         #[test]
1315         fn builds_invoice_request_with_quantity() {
1316                 let one = NonZeroU64::new(1).unwrap();
1317                 let ten = NonZeroU64::new(10).unwrap();
1318
1319                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1320                         .amount_msats(1000)
1321                         .supported_quantity(Quantity::One)
1322                         .build().unwrap()
1323                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1324                         .build().unwrap()
1325                         .sign(payer_sign).unwrap();
1326                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1327                 assert_eq!(invoice_request.quantity(), None);
1328                 assert_eq!(tlv_stream.quantity, None);
1329
1330                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1331                         .amount_msats(1000)
1332                         .supported_quantity(Quantity::One)
1333                         .build().unwrap()
1334                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1335                         .amount_msats(2_000).unwrap()
1336                         .quantity(2)
1337                 {
1338                         Ok(_) => panic!("expected error"),
1339                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnexpectedQuantity),
1340                 }
1341
1342                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1343                         .amount_msats(1000)
1344                         .supported_quantity(Quantity::Bounded(ten))
1345                         .build().unwrap()
1346                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1347                         .amount_msats(10_000).unwrap()
1348                         .quantity(10).unwrap()
1349                         .build().unwrap()
1350                         .sign(payer_sign).unwrap();
1351                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1352                 assert_eq!(invoice_request.amount_msats(), Some(10_000));
1353                 assert_eq!(tlv_stream.amount, Some(10_000));
1354
1355                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1356                         .amount_msats(1000)
1357                         .supported_quantity(Quantity::Bounded(ten))
1358                         .build().unwrap()
1359                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1360                         .amount_msats(11_000).unwrap()
1361                         .quantity(11)
1362                 {
1363                         Ok(_) => panic!("expected error"),
1364                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidQuantity),
1365                 }
1366
1367                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1368                         .amount_msats(1000)
1369                         .supported_quantity(Quantity::Unbounded)
1370                         .build().unwrap()
1371                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1372                         .amount_msats(2_000).unwrap()
1373                         .quantity(2).unwrap()
1374                         .build().unwrap()
1375                         .sign(payer_sign).unwrap();
1376                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1377                 assert_eq!(invoice_request.amount_msats(), Some(2_000));
1378                 assert_eq!(tlv_stream.amount, Some(2_000));
1379
1380                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1381                         .amount_msats(1000)
1382                         .supported_quantity(Quantity::Unbounded)
1383                         .build().unwrap()
1384                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1385                         .build()
1386                 {
1387                         Ok(_) => panic!("expected error"),
1388                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
1389                 }
1390
1391                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1392                         .amount_msats(1000)
1393                         .supported_quantity(Quantity::Bounded(one))
1394                         .build().unwrap()
1395                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1396                         .build()
1397                 {
1398                         Ok(_) => panic!("expected error"),
1399                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
1400                 }
1401         }
1402
1403         #[test]
1404         fn builds_invoice_request_with_payer_note() {
1405                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1406                         .amount_msats(1000)
1407                         .build().unwrap()
1408                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1409                         .payer_note("bar".into())
1410                         .build().unwrap()
1411                         .sign(payer_sign).unwrap();
1412                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1413                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("bar")));
1414                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
1415
1416                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1417                         .amount_msats(1000)
1418                         .build().unwrap()
1419                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1420                         .payer_note("bar".into())
1421                         .payer_note("baz".into())
1422                         .build().unwrap()
1423                         .sign(payer_sign).unwrap();
1424                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1425                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("baz")));
1426                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
1427         }
1428
1429         #[test]
1430         fn fails_signing_invoice_request() {
1431                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1432                         .amount_msats(1000)
1433                         .build().unwrap()
1434                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1435                         .build().unwrap()
1436                         .sign(|_| Err(()))
1437                 {
1438                         Ok(_) => panic!("expected error"),
1439                         Err(e) => assert_eq!(e, SignError::Signing(())),
1440                 }
1441
1442                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1443                         .amount_msats(1000)
1444                         .build().unwrap()
1445                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1446                         .build().unwrap()
1447                         .sign(recipient_sign)
1448                 {
1449                         Ok(_) => panic!("expected error"),
1450                         Err(e) => assert_eq!(e, SignError::Verification(secp256k1::Error::InvalidSignature)),
1451                 }
1452         }
1453
1454         #[test]
1455         fn fails_responding_with_unknown_required_features() {
1456                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1457                         .amount_msats(1000)
1458                         .build().unwrap()
1459                         .request_invoice(vec![42; 32], payer_pubkey()).unwrap()
1460                         .features_unchecked(InvoiceRequestFeatures::unknown())
1461                         .build().unwrap()
1462                         .sign(payer_sign).unwrap()
1463                         .respond_with_no_std(payment_paths(), payment_hash(), now())
1464                 {
1465                         Ok(_) => panic!("expected error"),
1466                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1467                 }
1468         }
1469
1470         #[test]
1471         fn parses_invoice_request_with_metadata() {
1472                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1473                         .amount_msats(1000)
1474                         .build().unwrap()
1475                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1476                         .build().unwrap()
1477                         .sign(payer_sign).unwrap();
1478
1479                 let mut buffer = Vec::new();
1480                 invoice_request.write(&mut buffer).unwrap();
1481
1482                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1483                         panic!("error parsing invoice_request: {:?}", e);
1484                 }
1485         }
1486
1487         #[test]
1488         fn parses_invoice_request_with_chain() {
1489                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1490                         .amount_msats(1000)
1491                         .build().unwrap()
1492                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1493                         .chain(Network::Bitcoin).unwrap()
1494                         .build().unwrap()
1495                         .sign(payer_sign).unwrap();
1496
1497                 let mut buffer = Vec::new();
1498                 invoice_request.write(&mut buffer).unwrap();
1499
1500                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1501                         panic!("error parsing invoice_request: {:?}", e);
1502                 }
1503
1504                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1505                         .amount_msats(1000)
1506                         .build().unwrap()
1507                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1508                         .chain_unchecked(Network::Testnet)
1509                         .build_unchecked()
1510                         .sign(payer_sign).unwrap();
1511
1512                 let mut buffer = Vec::new();
1513                 invoice_request.write(&mut buffer).unwrap();
1514
1515                 match InvoiceRequest::try_from(buffer) {
1516                         Ok(_) => panic!("expected error"),
1517                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnsupportedChain)),
1518                 }
1519         }
1520
1521         #[test]
1522         fn parses_invoice_request_with_amount() {
1523                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1524                         .amount_msats(1000)
1525                         .build().unwrap()
1526                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1527                         .build().unwrap()
1528                         .sign(payer_sign).unwrap();
1529
1530                 let mut buffer = Vec::new();
1531                 invoice_request.write(&mut buffer).unwrap();
1532
1533                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1534                         panic!("error parsing invoice_request: {:?}", e);
1535                 }
1536
1537                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1538                         .build().unwrap()
1539                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1540                         .amount_msats(1000).unwrap()
1541                         .build().unwrap()
1542                         .sign(payer_sign).unwrap();
1543
1544                 let mut buffer = Vec::new();
1545                 invoice_request.write(&mut buffer).unwrap();
1546
1547                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1548                         panic!("error parsing invoice_request: {:?}", e);
1549                 }
1550
1551                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1552                         .build().unwrap()
1553                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1554                         .build_unchecked()
1555                         .sign(payer_sign).unwrap();
1556
1557                 let mut buffer = Vec::new();
1558                 invoice_request.write(&mut buffer).unwrap();
1559
1560                 match InvoiceRequest::try_from(buffer) {
1561                         Ok(_) => panic!("expected error"),
1562                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1563                 }
1564
1565                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1566                         .amount_msats(1000)
1567                         .build().unwrap()
1568                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1569                         .amount_msats_unchecked(999)
1570                         .build_unchecked()
1571                         .sign(payer_sign).unwrap();
1572
1573                 let mut buffer = Vec::new();
1574                 invoice_request.write(&mut buffer).unwrap();
1575
1576                 match InvoiceRequest::try_from(buffer) {
1577                         Ok(_) => panic!("expected error"),
1578                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InsufficientAmount)),
1579                 }
1580
1581                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1582                         .amount(Amount::Currency { iso4217_code: *b"USD", amount: 1000 })
1583                         .build_unchecked()
1584                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1585                         .build_unchecked()
1586                         .sign(payer_sign).unwrap();
1587
1588                 let mut buffer = Vec::new();
1589                 invoice_request.write(&mut buffer).unwrap();
1590
1591                 match InvoiceRequest::try_from(buffer) {
1592                         Ok(_) => panic!("expected error"),
1593                         Err(e) => {
1594                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnsupportedCurrency));
1595                         },
1596                 }
1597
1598                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1599                         .amount_msats(1000)
1600                         .supported_quantity(Quantity::Unbounded)
1601                         .build().unwrap()
1602                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1603                         .quantity(u64::max_value()).unwrap()
1604                         .build_unchecked()
1605                         .sign(payer_sign).unwrap();
1606
1607                 let mut buffer = Vec::new();
1608                 invoice_request.write(&mut buffer).unwrap();
1609
1610                 match InvoiceRequest::try_from(buffer) {
1611                         Ok(_) => panic!("expected error"),
1612                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1613                 }
1614         }
1615
1616         #[test]
1617         fn parses_invoice_request_with_quantity() {
1618                 let one = NonZeroU64::new(1).unwrap();
1619                 let ten = NonZeroU64::new(10).unwrap();
1620
1621                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1622                         .amount_msats(1000)
1623                         .supported_quantity(Quantity::One)
1624                         .build().unwrap()
1625                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1626                         .build().unwrap()
1627                         .sign(payer_sign).unwrap();
1628
1629                 let mut buffer = Vec::new();
1630                 invoice_request.write(&mut buffer).unwrap();
1631
1632                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1633                         panic!("error parsing invoice_request: {:?}", e);
1634                 }
1635
1636                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1637                         .amount_msats(1000)
1638                         .supported_quantity(Quantity::One)
1639                         .build().unwrap()
1640                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1641                         .amount_msats(2_000).unwrap()
1642                         .quantity_unchecked(2)
1643                         .build_unchecked()
1644                         .sign(payer_sign).unwrap();
1645
1646                 let mut buffer = Vec::new();
1647                 invoice_request.write(&mut buffer).unwrap();
1648
1649                 match InvoiceRequest::try_from(buffer) {
1650                         Ok(_) => panic!("expected error"),
1651                         Err(e) => {
1652                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnexpectedQuantity));
1653                         },
1654                 }
1655
1656                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1657                         .amount_msats(1000)
1658                         .supported_quantity(Quantity::Bounded(ten))
1659                         .build().unwrap()
1660                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1661                         .amount_msats(10_000).unwrap()
1662                         .quantity(10).unwrap()
1663                         .build().unwrap()
1664                         .sign(payer_sign).unwrap();
1665
1666                 let mut buffer = Vec::new();
1667                 invoice_request.write(&mut buffer).unwrap();
1668
1669                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1670                         panic!("error parsing invoice_request: {:?}", e);
1671                 }
1672
1673                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1674                         .amount_msats(1000)
1675                         .supported_quantity(Quantity::Bounded(ten))
1676                         .build().unwrap()
1677                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1678                         .amount_msats(11_000).unwrap()
1679                         .quantity_unchecked(11)
1680                         .build_unchecked()
1681                         .sign(payer_sign).unwrap();
1682
1683                 let mut buffer = Vec::new();
1684                 invoice_request.write(&mut buffer).unwrap();
1685
1686                 match InvoiceRequest::try_from(buffer) {
1687                         Ok(_) => panic!("expected error"),
1688                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidQuantity)),
1689                 }
1690
1691                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1692                         .amount_msats(1000)
1693                         .supported_quantity(Quantity::Unbounded)
1694                         .build().unwrap()
1695                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1696                         .amount_msats(2_000).unwrap()
1697                         .quantity(2).unwrap()
1698                         .build().unwrap()
1699                         .sign(payer_sign).unwrap();
1700
1701                 let mut buffer = Vec::new();
1702                 invoice_request.write(&mut buffer).unwrap();
1703
1704                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1705                         panic!("error parsing invoice_request: {:?}", e);
1706                 }
1707
1708                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1709                         .amount_msats(1000)
1710                         .supported_quantity(Quantity::Unbounded)
1711                         .build().unwrap()
1712                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1713                         .build_unchecked()
1714                         .sign(payer_sign).unwrap();
1715
1716                 let mut buffer = Vec::new();
1717                 invoice_request.write(&mut buffer).unwrap();
1718
1719                 match InvoiceRequest::try_from(buffer) {
1720                         Ok(_) => panic!("expected error"),
1721                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
1722                 }
1723
1724                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1725                         .amount_msats(1000)
1726                         .supported_quantity(Quantity::Bounded(one))
1727                         .build().unwrap()
1728                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1729                         .build_unchecked()
1730                         .sign(payer_sign).unwrap();
1731
1732                 let mut buffer = Vec::new();
1733                 invoice_request.write(&mut buffer).unwrap();
1734
1735                 match InvoiceRequest::try_from(buffer) {
1736                         Ok(_) => panic!("expected error"),
1737                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
1738                 }
1739         }
1740
1741         #[test]
1742         fn fails_parsing_invoice_request_without_metadata() {
1743                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1744                         .amount_msats(1000)
1745                         .build().unwrap();
1746                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1747                         .build().unwrap();
1748                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
1749                 tlv_stream.0.metadata = None;
1750
1751                 let mut buffer = Vec::new();
1752                 tlv_stream.write(&mut buffer).unwrap();
1753
1754                 match InvoiceRequest::try_from(buffer) {
1755                         Ok(_) => panic!("expected error"),
1756                         Err(e) => {
1757                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPayerMetadata));
1758                         },
1759                 }
1760         }
1761
1762         #[test]
1763         fn fails_parsing_invoice_request_without_payer_id() {
1764                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1765                         .amount_msats(1000)
1766                         .build().unwrap();
1767                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1768                         .build().unwrap();
1769                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
1770                 tlv_stream.2.payer_id = None;
1771
1772                 let mut buffer = Vec::new();
1773                 tlv_stream.write(&mut buffer).unwrap();
1774
1775                 match InvoiceRequest::try_from(buffer) {
1776                         Ok(_) => panic!("expected error"),
1777                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPayerId)),
1778                 }
1779         }
1780
1781         #[test]
1782         fn fails_parsing_invoice_request_without_node_id() {
1783                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1784                         .amount_msats(1000)
1785                         .build().unwrap();
1786                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1787                         .build().unwrap();
1788                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
1789                 tlv_stream.1.node_id = None;
1790
1791                 let mut buffer = Vec::new();
1792                 tlv_stream.write(&mut buffer).unwrap();
1793
1794                 match InvoiceRequest::try_from(buffer) {
1795                         Ok(_) => panic!("expected error"),
1796                         Err(e) => {
1797                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1798                         },
1799                 }
1800         }
1801
1802         #[test]
1803         fn fails_parsing_invoice_request_without_signature() {
1804                 let mut buffer = Vec::new();
1805                 OfferBuilder::new("foo".into(), recipient_pubkey())
1806                         .amount_msats(1000)
1807                         .build().unwrap()
1808                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1809                         .build().unwrap()
1810                         .contents
1811                         .write(&mut buffer).unwrap();
1812
1813                 match InvoiceRequest::try_from(buffer) {
1814                         Ok(_) => panic!("expected error"),
1815                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
1816                 }
1817         }
1818
1819         #[test]
1820         fn fails_parsing_invoice_request_with_invalid_signature() {
1821                 let mut invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1822                         .amount_msats(1000)
1823                         .build().unwrap()
1824                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1825                         .build().unwrap()
1826                         .sign(payer_sign).unwrap();
1827                 let last_signature_byte = invoice_request.bytes.last_mut().unwrap();
1828                 *last_signature_byte = last_signature_byte.wrapping_add(1);
1829
1830                 let mut buffer = Vec::new();
1831                 invoice_request.write(&mut buffer).unwrap();
1832
1833                 match InvoiceRequest::try_from(buffer) {
1834                         Ok(_) => panic!("expected error"),
1835                         Err(e) => {
1836                                 assert_eq!(e, Bolt12ParseError::InvalidSignature(secp256k1::Error::InvalidSignature));
1837                         },
1838                 }
1839         }
1840
1841         #[test]
1842         fn fails_parsing_invoice_request_with_extra_tlv_records() {
1843                 let secp_ctx = Secp256k1::new();
1844                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1845                 let invoice_request = OfferBuilder::new("foo".into(), keys.public_key())
1846                         .amount_msats(1000)
1847                         .build().unwrap()
1848                         .request_invoice(vec![1; 32], keys.public_key()).unwrap()
1849                         .build().unwrap()
1850                         .sign::<_, Infallible>(
1851                                 |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
1852                         )
1853                         .unwrap();
1854
1855                 let mut encoded_invoice_request = Vec::new();
1856                 invoice_request.write(&mut encoded_invoice_request).unwrap();
1857                 BigSize(1002).write(&mut encoded_invoice_request).unwrap();
1858                 BigSize(32).write(&mut encoded_invoice_request).unwrap();
1859                 [42u8; 32].write(&mut encoded_invoice_request).unwrap();
1860
1861                 match InvoiceRequest::try_from(encoded_invoice_request) {
1862                         Ok(_) => panic!("expected error"),
1863                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1864                 }
1865         }
1866 }