git.bitcoin.ninja Git - rust-lightning/blob - lightning/src/offers/invoice_request.rs

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! Data structures and encoding for `invoice_request` messages.
  11 //!
  12 //! An [`InvoiceRequest`] can be built from a parsed [`Offer`] as an "offer to be paid". It is
  13 //! typically constructed by a customer and sent to the merchant who had published the corresponding
  14 //! offer. The recipient of the request responds with a [`Bolt12Invoice`].
  15 //!
  16 //! For an "offer for money" (e.g., refund, ATM withdrawal), where an offer doesn't exist as a
  17 //! precursor, see [`Refund`].
  18 //!
  19 //! [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
  20 //! [`Refund`]: crate::offers::refund::Refund
  21 //!
  22 //! ```
  23 //! extern crate bitcoin;
  24 //! extern crate lightning;
  25 //!
  26 //! use bitcoin::network::constants::Network;
  27 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
  28 //! use core::convert::Infallible;
  29 //! use lightning::ln::features::OfferFeatures;
  30 //! use lightning::offers::offer::Offer;
  31 //! use lightning::util::ser::Writeable;
  32 //!
  33 //! # fn parse() -> Result<(), lightning::offers::parse::Bolt12ParseError> {
  34 //! let secp_ctx = Secp256k1::new();
  35 //! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32])?);
  36 //! let pubkey = PublicKey::from(keys);
  37 //! let mut buffer = Vec::new();
  38 //!
  39 //! "lno1qcp4256ypq"
  40 //!     .parse::<Offer>()?
  41 //!     .request_invoice(vec![42; 64], pubkey)?
  42 //!     .chain(Network::Testnet)?
  43 //!     .amount_msats(1000)?
  44 //!     .quantity(5)?
  45 //!     .payer_note("foo".to_string())
  46 //!     .build()?
  47 //!     .sign::<_, Infallible>(
  48 //!         |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
  49 //!     )
  50 //!     .expect("failed verifying signature")
  51 //!     .write(&mut buffer)
  52 //!     .unwrap();
  53 //! # Ok(())
  54 //! # }
  55 //! ```
  56
  57 use bitcoin::blockdata::constants::ChainHash;
  58 use bitcoin::network::constants::Network;
  59 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, self};
  60 use bitcoin::secp256k1::schnorr::Signature;
  61 use core::convert::{AsRef, Infallible, TryFrom};
  62 use core::ops::Deref;
  63 use crate::sign::EntropySource;
  64 use crate::io;
  65 use crate::blinded_path::BlindedPath;
  66 use crate::ln::PaymentHash;
  67 use crate::ln::channelmanager::PaymentId;
  68 use crate::ln::features::InvoiceRequestFeatures;
  69 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
  70 use crate::ln::msgs::DecodeError;
  71 use crate::offers::invoice::{BlindedPayInfo, DerivedSigningPubkey, ExplicitSigningPubkey, InvoiceBuilder};
  72 use crate::offers::merkle::{SignError, SignatureTlvStream, SignatureTlvStreamRef, TaggedHash, self};
  73 use crate::offers::offer::{Offer, OfferContents, OfferTlvStream, OfferTlvStreamRef};
  74 use crate::offers::parse::{Bolt12ParseError, ParsedMessage, Bolt12SemanticError};
  75 use crate::offers::payer::{PayerContents, PayerTlvStream, PayerTlvStreamRef};
  76 use crate::offers::signer::{Metadata, MetadataMaterial};
  77 use crate::util::ser::{HighZeroBytesDroppedBigSize, SeekReadable, WithoutLength, Writeable, Writer};
  78 use crate::util::string::PrintableString;
  79
  80 use crate::prelude::*;
  81
  82 /// Tag for the hash function used when signing an [`InvoiceRequest`]'s merkle root.
  83 pub const SIGNATURE_TAG: &'static str = concat!("lightning", "invoice_request", "signature");
  84
  85 pub(super) const IV_BYTES: &[u8; IV_LEN] = b"LDK Invreq ~~~~~";
  86
  87 /// Builds an [`InvoiceRequest`] from an [`Offer`] for the "offer to be paid" flow.
  88 ///
  89 /// See [module-level documentation] for usage.
  90 ///
  91 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
  92 ///
  93 /// [module-level documentation]: self
  94 pub struct InvoiceRequestBuilder<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> {
  95         offer: &'a Offer,
  96         invoice_request: InvoiceRequestContentsWithoutPayerId,
  97         payer_id: Option<PublicKey>,
  98         payer_id_strategy: core::marker::PhantomData<P>,
  99         secp_ctx: Option<&'b Secp256k1<T>>,
 100 }
 101
 102 /// Indicates how [`InvoiceRequest::payer_id`] will be set.
 103 ///
 104 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 105 pub trait PayerIdStrategy {}
 106
 107 /// [`InvoiceRequest::payer_id`] will be explicitly set.
 108 ///
 109 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 110 pub struct ExplicitPayerId {}
 111
 112 /// [`InvoiceRequest::payer_id`] will be derived.
 113 ///
 114 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 115 pub struct DerivedPayerId {}
 116
 117 impl PayerIdStrategy for ExplicitPayerId {}
 118 impl PayerIdStrategy for DerivedPayerId {}
 119
 120 impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, ExplicitPayerId, T> {
 121         pub(super) fn new(offer: &'a Offer, metadata: Vec<u8>, payer_id: PublicKey) -> Self {
 122                 Self {
 123                         offer,
 124                         invoice_request: Self::create_contents(offer, Metadata::Bytes(metadata)),
 125                         payer_id: Some(payer_id),
 126                         payer_id_strategy: core::marker::PhantomData,
 127                         secp_ctx: None,
 128                 }
 129         }
 130
 131         pub(super) fn deriving_metadata<ES: Deref>(
 132                 offer: &'a Offer, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
 133                 payment_id: PaymentId,
 134         ) -> Self where ES::Target: EntropySource {
 135                 let nonce = Nonce::from_entropy_source(entropy_source);
 136                 let payment_id = Some(payment_id);
 137                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, payment_id);
 138                 let metadata = Metadata::Derived(derivation_material);
 139                 Self {
 140                         offer,
 141                         invoice_request: Self::create_contents(offer, metadata),
 142                         payer_id: Some(payer_id),
 143                         payer_id_strategy: core::marker::PhantomData,
 144                         secp_ctx: None,
 145                 }
 146         }
 147
 148         /// Builds an unsigned [`InvoiceRequest`] after checking for valid semantics. It can be signed
 149         /// by [`UnsignedInvoiceRequest::sign`].
 150         pub fn build(self) -> Result<UnsignedInvoiceRequest, Bolt12SemanticError> {
 151                 let (unsigned_invoice_request, keys, _) = self.build_with_checks()?;
 152                 debug_assert!(keys.is_none());
 153                 Ok(unsigned_invoice_request)
 154         }
 155 }
 156
 157 impl<'a, 'b, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T> {
 158         pub(super) fn deriving_payer_id<ES: Deref>(
 159                 offer: &'a Offer, expanded_key: &ExpandedKey, entropy_source: ES,
 160                 secp_ctx: &'b Secp256k1<T>, payment_id: PaymentId
 161         ) -> Self where ES::Target: EntropySource {
 162                 let nonce = Nonce::from_entropy_source(entropy_source);
 163                 let payment_id = Some(payment_id);
 164                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES, payment_id);
 165                 let metadata = Metadata::DerivedSigningPubkey(derivation_material);
 166                 Self {
 167                         offer,
 168                         invoice_request: Self::create_contents(offer, metadata),
 169                         payer_id: None,
 170                         payer_id_strategy: core::marker::PhantomData,
 171                         secp_ctx: Some(secp_ctx),
 172                 }
 173         }
 174
 175         /// Builds a signed [`InvoiceRequest`] after checking for valid semantics.
 176         pub fn build_and_sign(self) -> Result<InvoiceRequest, Bolt12SemanticError> {
 177                 let (unsigned_invoice_request, keys, secp_ctx) = self.build_with_checks()?;
 178                 debug_assert!(keys.is_some());
 179
 180                 let secp_ctx = secp_ctx.unwrap();
 181                 let keys = keys.unwrap();
 182                 let invoice_request = unsigned_invoice_request
 183                         .sign::<_, Infallible>(
 184                                 |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
 185                         )
 186                         .unwrap();
 187                 Ok(invoice_request)
 188         }
 189 }
 190
 191 impl<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, P, T> {
 192         fn create_contents(offer: &Offer, metadata: Metadata) -> InvoiceRequestContentsWithoutPayerId {
 193                 let offer = offer.contents.clone();
 194                 InvoiceRequestContentsWithoutPayerId {
 195                         payer: PayerContents(metadata), offer, chain: None, amount_msats: None,
 196                         features: InvoiceRequestFeatures::empty(), quantity: None, payer_note: None,
 197                 }
 198         }
 199
 200         /// Sets the [`InvoiceRequest::chain`] of the given [`Network`] for paying an invoice. If not
 201         /// called, [`Network::Bitcoin`] is assumed. Errors if the chain for `network` is not supported
 202         /// by the offer.
 203         ///
 204         /// Successive calls to this method will override the previous setting.
 205         pub fn chain(self, network: Network) -> Result<Self, Bolt12SemanticError> {
 206                 self.chain_hash(ChainHash::using_genesis_block(network))
 207         }
 208
 209         /// Sets the [`InvoiceRequest::chain`] for paying an invoice. If not called, the chain hash of
 210         /// [`Network::Bitcoin`] is assumed. Errors if the chain for `network` is not supported by the
 211         /// offer.
 212         ///
 213         /// Successive calls to this method will override the previous setting.
 214         pub(crate) fn chain_hash(mut self, chain: ChainHash) -> Result<Self, Bolt12SemanticError> {
 215                 if !self.offer.supports_chain(chain) {
 216                         return Err(Bolt12SemanticError::UnsupportedChain);
 217                 }
 218
 219                 self.invoice_request.chain = Some(chain);
 220                 Ok(self)
 221         }
 222
 223         /// Sets the [`InvoiceRequest::amount_msats`] for paying an invoice. Errors if `amount_msats` is
 224         /// not at least the expected invoice amount (i.e., [`Offer::amount`] times [`quantity`]).
 225         ///
 226         /// Successive calls to this method will override the previous setting.
 227         ///
 228         /// [`quantity`]: Self::quantity
 229         pub fn amount_msats(mut self, amount_msats: u64) -> Result<Self, Bolt12SemanticError> {
 230                 self.invoice_request.offer.check_amount_msats_for_quantity(
 231                         Some(amount_msats), self.invoice_request.quantity
 232                 )?;
 233                 self.invoice_request.amount_msats = Some(amount_msats);
 234                 Ok(self)
 235         }
 236
 237         /// Sets [`InvoiceRequest::quantity`] of items. If not set, `1` is assumed. Errors if `quantity`
 238         /// does not conform to [`Offer::is_valid_quantity`].
 239         ///
 240         /// Successive calls to this method will override the previous setting.
 241         pub fn quantity(mut self, quantity: u64) -> Result<Self, Bolt12SemanticError> {
 242                 self.invoice_request.offer.check_quantity(Some(quantity))?;
 243                 self.invoice_request.quantity = Some(quantity);
 244                 Ok(self)
 245         }
 246
 247         /// Sets the [`InvoiceRequest::payer_note`].
 248         ///
 249         /// Successive calls to this method will override the previous setting.
 250         pub fn payer_note(mut self, payer_note: String) -> Self {
 251                 self.invoice_request.payer_note = Some(payer_note);
 252                 self
 253         }
 254
 255         fn build_with_checks(mut self) -> Result<
 256                 (UnsignedInvoiceRequest, Option<KeyPair>, Option<&'b Secp256k1<T>>),
 257                 Bolt12SemanticError
 258         > {
 259                 #[cfg(feature = "std")] {
 260                         if self.offer.is_expired() {
 261                                 return Err(Bolt12SemanticError::AlreadyExpired);
 262                         }
 263                 }
 264
 265                 let chain = self.invoice_request.chain();
 266                 if !self.offer.supports_chain(chain) {
 267                         return Err(Bolt12SemanticError::UnsupportedChain);
 268                 }
 269
 270                 if chain == self.offer.implied_chain() {
 271                         self.invoice_request.chain = None;
 272                 }
 273
 274                 if self.offer.amount().is_none() && self.invoice_request.amount_msats.is_none() {
 275                         return Err(Bolt12SemanticError::MissingAmount);
 276                 }
 277
 278                 self.invoice_request.offer.check_quantity(self.invoice_request.quantity)?;
 279                 self.invoice_request.offer.check_amount_msats_for_quantity(
 280                         self.invoice_request.amount_msats, self.invoice_request.quantity
 281                 )?;
 282
 283                 Ok(self.build_without_checks())
 284         }
 285
 286         fn build_without_checks(mut self) ->
 287                 (UnsignedInvoiceRequest, Option<KeyPair>, Option<&'b Secp256k1<T>>)
 288         {
 289                 // Create the metadata for stateless verification of a Bolt12Invoice.
 290                 let mut keys = None;
 291                 let secp_ctx = self.secp_ctx.clone();
 292                 if self.invoice_request.payer.0.has_derivation_material() {
 293                         let mut metadata = core::mem::take(&mut self.invoice_request.payer.0);
 294
 295                         let mut tlv_stream = self.invoice_request.as_tlv_stream();
 296                         debug_assert!(tlv_stream.2.payer_id.is_none());
 297                         tlv_stream.0.metadata = None;
 298                         if !metadata.derives_payer_keys() {
 299                                 tlv_stream.2.payer_id = self.payer_id.as_ref();
 300                         }
 301
 302                         let (derived_metadata, derived_keys) = metadata.derive_from(tlv_stream, self.secp_ctx);
 303                         metadata = derived_metadata;
 304                         keys = derived_keys;
 305                         if let Some(keys) = keys {
 306                                 debug_assert!(self.payer_id.is_none());
 307                                 self.payer_id = Some(keys.public_key());
 308                         }
 309
 310                         self.invoice_request.payer.0 = metadata;
 311                 }
 312
 313                 debug_assert!(self.invoice_request.payer.0.as_bytes().is_some());
 314                 debug_assert!(self.payer_id.is_some());
 315                 let payer_id = self.payer_id.unwrap();
 316
 317                 let invoice_request = InvoiceRequestContents {
 318                         inner: self.invoice_request,
 319                         payer_id,
 320                 };
 321                 let unsigned_invoice_request = UnsignedInvoiceRequest::new(self.offer, invoice_request);
 322
 323                 (unsigned_invoice_request, keys, secp_ctx)
 324         }
 325 }
 326
 327 #[cfg(test)]
 328 impl<'a, 'b, P: PayerIdStrategy, T: secp256k1::Signing> InvoiceRequestBuilder<'a, 'b, P, T> {
 329         fn chain_unchecked(mut self, network: Network) -> Self {
 330                 let chain = ChainHash::using_genesis_block(network);
 331                 self.invoice_request.chain = Some(chain);
 332                 self
 333         }
 334
 335         fn amount_msats_unchecked(mut self, amount_msats: u64) -> Self {
 336                 self.invoice_request.amount_msats = Some(amount_msats);
 337                 self
 338         }
 339
 340         fn features_unchecked(mut self, features: InvoiceRequestFeatures) -> Self {
 341                 self.invoice_request.features = features;
 342                 self
 343         }
 344
 345         fn quantity_unchecked(mut self, quantity: u64) -> Self {
 346                 self.invoice_request.quantity = Some(quantity);
 347                 self
 348         }
 349
 350         pub(super) fn build_unchecked(self) -> UnsignedInvoiceRequest {
 351                 self.build_without_checks().0
 352         }
 353 }
 354
 355 /// A semantically valid [`InvoiceRequest`] that hasn't been signed.
 356 ///
 357 /// # Serialization
 358 ///
 359 /// This is serialized as a TLV stream, which includes TLV records from the originating message. As
 360 /// such, it may include unknown, odd TLV records.
 361 pub struct UnsignedInvoiceRequest {
 362         bytes: Vec<u8>,
 363         contents: InvoiceRequestContents,
 364         tagged_hash: TaggedHash,
 365 }
 366
 367 impl UnsignedInvoiceRequest {
 368         fn new(offer: &Offer, contents: InvoiceRequestContents) -> Self {
 369                 // Use the offer bytes instead of the offer TLV stream as the offer may have contained
 370                 // unknown TLV records, which are not stored in `OfferContents`.
 371                 let (payer_tlv_stream, _offer_tlv_stream, invoice_request_tlv_stream) =
 372                         contents.as_tlv_stream();
 373                 let offer_bytes = WithoutLength(&offer.bytes);
 374                 let unsigned_tlv_stream = (payer_tlv_stream, offer_bytes, invoice_request_tlv_stream);
 375
 376                 let mut bytes = Vec::new();
 377                 unsigned_tlv_stream.write(&mut bytes).unwrap();
 378
 379                 let tagged_hash = TaggedHash::new(SIGNATURE_TAG, &bytes);
 380
 381                 Self { bytes, contents, tagged_hash }
 382         }
 383
 384         /// Returns the [`TaggedHash`] of the invoice to sign.
 385         pub fn tagged_hash(&self) -> &TaggedHash {
 386                 &self.tagged_hash
 387         }
 388
 389         /// Signs the [`TaggedHash`] of the invoice request using the given function.
 390         ///
 391         /// Note: The hash computation may have included unknown, odd TLV records.
 392         ///
 393         /// This is not exported to bindings users as functions are not yet mapped.
 394         pub fn sign<F, E>(mut self, sign: F) -> Result<InvoiceRequest, SignError<E>>
 395         where
 396                 F: FnOnce(&Self) -> Result<Signature, E>
 397         {
 398                 let pubkey = self.contents.payer_id;
 399                 let signature = merkle::sign_message(sign, &self, pubkey)?;
 400
 401                 // Append the signature TLV record to the bytes.
 402                 let signature_tlv_stream = SignatureTlvStreamRef {
 403                         signature: Some(&signature),
 404                 };
 405                 signature_tlv_stream.write(&mut self.bytes).unwrap();
 406
 407                 Ok(InvoiceRequest {
 408                         bytes: self.bytes,
 409                         contents: self.contents,
 410                         signature,
 411                 })
 412         }
 413 }
 414
 415 impl AsRef<TaggedHash> for UnsignedInvoiceRequest {
 416         fn as_ref(&self) -> &TaggedHash {
 417                 &self.tagged_hash
 418         }
 419 }
 420
 421 /// An `InvoiceRequest` is a request for a [`Bolt12Invoice`] formulated from an [`Offer`].
 422 ///
 423 /// An offer may provide choices such as quantity, amount, chain, features, etc. An invoice request
 424 /// specifies these such that its recipient can send an invoice for payment.
 425 ///
 426 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 427 /// [`Offer`]: crate::offers::offer::Offer
 428 #[derive(Clone, Debug)]
 429 #[cfg_attr(test, derive(PartialEq))]
 430 pub struct InvoiceRequest {
 431         pub(super) bytes: Vec<u8>,
 432         pub(super) contents: InvoiceRequestContents,
 433         signature: Signature,
 434 }
 435
 436 /// An [`InvoiceRequest`] that has been verified by [`InvoiceRequest::verify`] and exposes different
 437 /// ways to respond depending on whether the signing keys were derived.
 438 #[derive(Clone, Debug)]
 439 pub struct VerifiedInvoiceRequest {
 440         /// The verified request.
 441         inner: InvoiceRequest,
 442
 443         /// Keys used for signing a [`Bolt12Invoice`] if they can be derived.
 444         ///
 445         /// If `Some`, must call [`respond_using_derived_keys`] when responding. Otherwise, call
 446         /// [`respond_with`].
 447         ///
 448         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 449         /// [`respond_using_derived_keys`]: Self::respond_using_derived_keys
 450         /// [`respond_with`]: Self::respond_with
 451         pub keys: Option<KeyPair>,
 452 }
 453
 454 /// The contents of an [`InvoiceRequest`], which may be shared with an [`Bolt12Invoice`].
 455 ///
 456 /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 457 #[derive(Clone, Debug)]
 458 #[cfg_attr(test, derive(PartialEq))]
 459 pub(super) struct InvoiceRequestContents {
 460         pub(super) inner: InvoiceRequestContentsWithoutPayerId,
 461         payer_id: PublicKey,
 462 }
 463
 464 #[derive(Clone, Debug)]
 465 #[cfg_attr(test, derive(PartialEq))]
 466 pub(super) struct InvoiceRequestContentsWithoutPayerId {
 467         payer: PayerContents,
 468         pub(super) offer: OfferContents,
 469         chain: Option<ChainHash>,
 470         amount_msats: Option<u64>,
 471         features: InvoiceRequestFeatures,
 472         quantity: Option<u64>,
 473         payer_note: Option<String>,
 474 }
 475
 476 macro_rules! invoice_request_accessors { ($self: ident, $contents: expr) => {
 477         /// An unpredictable series of bytes, typically containing information about the derivation of
 478         /// [`payer_id`].
 479         ///
 480         /// [`payer_id`]: Self::payer_id
 481         pub fn payer_metadata(&$self) -> &[u8] {
 482                 $contents.metadata()
 483         }
 484
 485         /// A chain from [`Offer::chains`] that the offer is valid for.
 486         pub fn chain(&$self) -> ChainHash {
 487                 $contents.chain()
 488         }
 489
 490         /// The amount to pay in msats (i.e., the minimum lightning-payable unit for [`chain`]), which
 491         /// must be greater than or equal to [`Offer::amount`], converted if necessary.
 492         ///
 493         /// [`chain`]: Self::chain
 494         pub fn amount_msats(&$self) -> Option<u64> {
 495                 $contents.amount_msats()
 496         }
 497
 498         /// Features pertaining to requesting an invoice.
 499         pub fn invoice_request_features(&$self) -> &InvoiceRequestFeatures {
 500                 &$contents.features()
 501         }
 502
 503         /// The quantity of the offer's item conforming to [`Offer::is_valid_quantity`].
 504         pub fn quantity(&$self) -> Option<u64> {
 505                 $contents.quantity()
 506         }
 507
 508         /// A possibly transient pubkey used to sign the invoice request.
 509         pub fn payer_id(&$self) -> PublicKey {
 510                 $contents.payer_id()
 511         }
 512
 513         /// A payer-provided note which will be seen by the recipient and reflected back in the invoice
 514         /// response.
 515         pub fn payer_note(&$self) -> Option<PrintableString> {
 516                 $contents.payer_note()
 517         }
 518 } }
 519
 520 impl UnsignedInvoiceRequest {
 521         offer_accessors!(self, self.contents.inner.offer);
 522         invoice_request_accessors!(self, self.contents);
 523 }
 524
 525 impl InvoiceRequest {
 526         offer_accessors!(self, self.contents.inner.offer);
 527         invoice_request_accessors!(self, self.contents);
 528
 529         /// Signature of the invoice request using [`payer_id`].
 530         ///
 531         /// [`payer_id`]: Self::payer_id
 532         pub fn signature(&self) -> Signature {
 533                 self.signature
 534         }
 535
 536         /// Creates an [`InvoiceBuilder`] for the request with the given required fields and using the
 537         /// [`Duration`] since [`std::time::SystemTime::UNIX_EPOCH`] as the creation time.
 538         ///
 539         /// See [`InvoiceRequest::respond_with_no_std`] for further details where the aforementioned
 540         /// creation time is used for the `created_at` parameter.
 541         ///
 542         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 543         ///
 544         /// [`Duration`]: core::time::Duration
 545         #[cfg(feature = "std")]
 546         pub fn respond_with(
 547                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash
 548         ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, Bolt12SemanticError> {
 549                 let created_at = std::time::SystemTime::now()
 550                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 551                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 552
 553                 self.respond_with_no_std(payment_paths, payment_hash, created_at)
 554         }
 555
 556         /// Creates an [`InvoiceBuilder`] for the request with the given required fields.
 557         ///
 558         /// Unless [`InvoiceBuilder::relative_expiry`] is set, the invoice will expire two hours after
 559         /// `created_at`, which is used to set [`Bolt12Invoice::created_at`]. Useful for `no-std` builds
 560         /// where [`std::time::SystemTime`] is not available.
 561         ///
 562         /// The caller is expected to remember the preimage of `payment_hash` in order to claim a payment
 563         /// for the invoice.
 564         ///
 565         /// The `payment_paths` parameter is useful for maintaining the payment recipient's privacy. It
 566         /// must contain one or more elements ordered from most-preferred to least-preferred, if there's
 567         /// a preference. Note, however, that any privacy is lost if a public node id was used for
 568         /// [`Offer::signing_pubkey`].
 569         ///
 570         /// Errors if the request contains unknown required features.
 571         ///
 572         /// # Note
 573         ///
 574         /// If the originating [`Offer`] was created using [`OfferBuilder::deriving_signing_pubkey`],
 575         /// then use [`InvoiceRequest::verify`] and [`VerifiedInvoiceRequest`] methods instead.
 576         ///
 577         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 578         ///
 579         /// [`Bolt12Invoice::created_at`]: crate::offers::invoice::Bolt12Invoice::created_at
 580         /// [`OfferBuilder::deriving_signing_pubkey`]: crate::offers::offer::OfferBuilder::deriving_signing_pubkey
 581         pub fn respond_with_no_std(
 582                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 583                 created_at: core::time::Duration
 584         ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, Bolt12SemanticError> {
 585                 if self.invoice_request_features().requires_unknown_bits() {
 586                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 587                 }
 588
 589                 InvoiceBuilder::for_offer(self, payment_paths, created_at, payment_hash)
 590         }
 591
 592         /// Verifies that the request was for an offer created using the given key. Returns the verified
 593         /// request which contains the derived keys needed to sign a [`Bolt12Invoice`] for the request
 594         /// if they could be extracted from the metadata.
 595         ///
 596         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 597         pub fn verify<T: secp256k1::Signing>(
 598                 self, key: &ExpandedKey, secp_ctx: &Secp256k1<T>
 599         ) -> Result<VerifiedInvoiceRequest, ()> {
 600                 let keys = self.contents.inner.offer.verify(&self.bytes, key, secp_ctx)?;
 601                 Ok(VerifiedInvoiceRequest {
 602                         inner: self,
 603                         keys,
 604                 })
 605         }
 606
 607         pub(crate) fn as_tlv_stream(&self) -> FullInvoiceRequestTlvStreamRef {
 608                 let (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream) =
 609                         self.contents.as_tlv_stream();
 610                 let signature_tlv_stream = SignatureTlvStreamRef {
 611                         signature: Some(&self.signature),
 612                 };
 613                 (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, signature_tlv_stream)
 614         }
 615 }
 616
 617 impl VerifiedInvoiceRequest {
 618         offer_accessors!(self, self.inner.contents.inner.offer);
 619         invoice_request_accessors!(self, self.inner.contents);
 620
 621         /// Creates an [`InvoiceBuilder`] for the request with the given required fields and using the
 622         /// [`Duration`] since [`std::time::SystemTime::UNIX_EPOCH`] as the creation time.
 623         ///
 624         /// See [`InvoiceRequest::respond_with_no_std`] for further details.
 625         ///
 626         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 627         ///
 628         /// [`Duration`]: core::time::Duration
 629         #[cfg(feature = "std")]
 630         pub fn respond_with(
 631                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash
 632         ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, Bolt12SemanticError> {
 633                 self.inner.respond_with(payment_paths, payment_hash)
 634         }
 635
 636         /// Creates an [`InvoiceBuilder`] for the request with the given required fields.
 637         ///
 638         /// See [`InvoiceRequest::respond_with_no_std`] for further details.
 639         ///
 640         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 641         pub fn respond_with_no_std(
 642                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 643                 created_at: core::time::Duration
 644         ) -> Result<InvoiceBuilder<ExplicitSigningPubkey>, Bolt12SemanticError> {
 645                 self.inner.respond_with_no_std(payment_paths, payment_hash, created_at)
 646         }
 647
 648         /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
 649         /// derived signing keys from the originating [`Offer`] to sign the [`Bolt12Invoice`]. Must use
 650         /// the same [`ExpandedKey`] as the one used to create the offer.
 651         ///
 652         /// See [`InvoiceRequest::respond_with`] for further details.
 653         ///
 654         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 655         ///
 656         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 657         #[cfg(feature = "std")]
 658         pub fn respond_using_derived_keys(
 659                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash
 660         ) -> Result<InvoiceBuilder<DerivedSigningPubkey>, Bolt12SemanticError> {
 661                 let created_at = std::time::SystemTime::now()
 662                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 663                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 664
 665                 self.respond_using_derived_keys_no_std(payment_paths, payment_hash, created_at)
 666         }
 667
 668         /// Creates an [`InvoiceBuilder`] for the request using the given required fields and that uses
 669         /// derived signing keys from the originating [`Offer`] to sign the [`Bolt12Invoice`]. Must use
 670         /// the same [`ExpandedKey`] as the one used to create the offer.
 671         ///
 672         /// See [`InvoiceRequest::respond_with_no_std`] for further details.
 673         ///
 674         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
 675         ///
 676         /// [`Bolt12Invoice`]: crate::offers::invoice::Bolt12Invoice
 677         pub fn respond_using_derived_keys_no_std(
 678                 &self, payment_paths: Vec<(BlindedPayInfo, BlindedPath)>, payment_hash: PaymentHash,
 679                 created_at: core::time::Duration
 680         ) -> Result<InvoiceBuilder<DerivedSigningPubkey>, Bolt12SemanticError> {
 681                 if self.inner.invoice_request_features().requires_unknown_bits() {
 682                         return Err(Bolt12SemanticError::UnknownRequiredFeatures);
 683                 }
 684
 685                 let keys = match self.keys {
 686                         None => return Err(Bolt12SemanticError::InvalidMetadata),
 687                         Some(keys) => keys,
 688                 };
 689
 690                 InvoiceBuilder::for_offer_using_keys(
 691                         &self.inner, payment_paths, created_at, payment_hash, keys
 692                 )
 693         }
 694 }
 695
 696 impl InvoiceRequestContents {
 697         pub(super) fn metadata(&self) -> &[u8] {
 698                 self.inner.metadata()
 699         }
 700
 701         pub(super) fn derives_keys(&self) -> bool {
 702                 self.inner.payer.0.derives_payer_keys()
 703         }
 704
 705         pub(super) fn chain(&self) -> ChainHash {
 706                 self.inner.chain()
 707         }
 708
 709         pub(super) fn amount_msats(&self) -> Option<u64> {
 710                 self.inner.amount_msats
 711         }
 712
 713         pub(super) fn features(&self) -> &InvoiceRequestFeatures {
 714                 &self.inner.features
 715         }
 716
 717         pub(super) fn quantity(&self) -> Option<u64> {
 718                 self.inner.quantity
 719         }
 720
 721         pub(super) fn payer_id(&self) -> PublicKey {
 722                 self.payer_id
 723         }
 724
 725         pub(super) fn payer_note(&self) -> Option<PrintableString> {
 726                 self.inner.payer_note.as_ref()
 727                         .map(|payer_note| PrintableString(payer_note.as_str()))
 728         }
 729
 730         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 731                 let (payer, offer, mut invoice_request) = self.inner.as_tlv_stream();
 732                 invoice_request.payer_id = Some(&self.payer_id);
 733                 (payer, offer, invoice_request)
 734         }
 735 }
 736
 737 impl InvoiceRequestContentsWithoutPayerId {
 738         pub(super) fn metadata(&self) -> &[u8] {
 739                 self.payer.0.as_bytes().map(|bytes| bytes.as_slice()).unwrap_or(&[])
 740         }
 741
 742         pub(super) fn chain(&self) -> ChainHash {
 743                 self.chain.unwrap_or_else(|| self.offer.implied_chain())
 744         }
 745
 746         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 747                 let payer = PayerTlvStreamRef {
 748                         metadata: self.payer.0.as_bytes(),
 749                 };
 750
 751                 let offer = self.offer.as_tlv_stream();
 752
 753                 let features = {
 754                         if self.features == InvoiceRequestFeatures::empty() { None }
 755                         else { Some(&self.features) }
 756                 };
 757
 758                 let invoice_request = InvoiceRequestTlvStreamRef {
 759                         chain: self.chain.as_ref(),
 760                         amount: self.amount_msats,
 761                         features,
 762                         quantity: self.quantity,
 763                         payer_id: None,
 764                         payer_note: self.payer_note.as_ref(),
 765                 };
 766
 767                 (payer, offer, invoice_request)
 768         }
 769 }
 770
 771 impl Writeable for UnsignedInvoiceRequest {
 772         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 773                 WithoutLength(&self.bytes).write(writer)
 774         }
 775 }
 776
 777 impl Writeable for InvoiceRequest {
 778         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 779                 WithoutLength(&self.bytes).write(writer)
 780         }
 781 }
 782
 783 impl Writeable for InvoiceRequestContents {
 784         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 785                 self.as_tlv_stream().write(writer)
 786         }
 787 }
 788
 789 /// Valid type range for invoice_request TLV records.
 790 pub(super) const INVOICE_REQUEST_TYPES: core::ops::Range<u64> = 80..160;
 791
 792 /// TLV record type for [`InvoiceRequest::payer_id`] and [`Refund::payer_id`].
 793 ///
 794 /// [`Refund::payer_id`]: crate::offers::refund::Refund::payer_id
 795 pub(super) const INVOICE_REQUEST_PAYER_ID_TYPE: u64 = 88;
 796
 797 tlv_stream!(InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef, INVOICE_REQUEST_TYPES, {
 798         (80, chain: ChainHash),
 799         (82, amount: (u64, HighZeroBytesDroppedBigSize)),
 800         (84, features: (InvoiceRequestFeatures, WithoutLength)),
 801         (86, quantity: (u64, HighZeroBytesDroppedBigSize)),
 802         (INVOICE_REQUEST_PAYER_ID_TYPE, payer_id: PublicKey),
 803         (89, payer_note: (String, WithoutLength)),
 804 });
 805
 806 type FullInvoiceRequestTlvStream =
 807         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, SignatureTlvStream);
 808
 809 type FullInvoiceRequestTlvStreamRef<'a> = (
 810         PayerTlvStreamRef<'a>,
 811         OfferTlvStreamRef<'a>,
 812         InvoiceRequestTlvStreamRef<'a>,
 813         SignatureTlvStreamRef<'a>,
 814 );
 815
 816 impl SeekReadable for FullInvoiceRequestTlvStream {
 817         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 818                 let payer = SeekReadable::read(r)?;
 819                 let offer = SeekReadable::read(r)?;
 820                 let invoice_request = SeekReadable::read(r)?;
 821                 let signature = SeekReadable::read(r)?;
 822
 823                 Ok((payer, offer, invoice_request, signature))
 824         }
 825 }
 826
 827 type PartialInvoiceRequestTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
 828
 829 type PartialInvoiceRequestTlvStreamRef<'a> = (
 830         PayerTlvStreamRef<'a>,
 831         OfferTlvStreamRef<'a>,
 832         InvoiceRequestTlvStreamRef<'a>,
 833 );
 834
 835 impl TryFrom<Vec<u8>> for UnsignedInvoiceRequest {
 836         type Error = Bolt12ParseError;
 837
 838         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 839                 let invoice_request = ParsedMessage::<PartialInvoiceRequestTlvStream>::try_from(bytes)?;
 840                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
 841                 let (
 842                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
 843                 ) = tlv_stream;
 844                 let contents = InvoiceRequestContents::try_from(
 845                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 846                 )?;
 847
 848                 let tagged_hash = TaggedHash::new(SIGNATURE_TAG, &bytes);
 849
 850                 Ok(UnsignedInvoiceRequest { bytes, contents, tagged_hash })
 851         }
 852 }
 853
 854 impl TryFrom<Vec<u8>> for InvoiceRequest {
 855         type Error = Bolt12ParseError;
 856
 857         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 858                 let invoice_request = ParsedMessage::<FullInvoiceRequestTlvStream>::try_from(bytes)?;
 859                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
 860                 let (
 861                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
 862                         SignatureTlvStream { signature },
 863                 ) = tlv_stream;
 864                 let contents = InvoiceRequestContents::try_from(
 865                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 866                 )?;
 867
 868                 let signature = match signature {
 869                         None => return Err(Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
 870                         Some(signature) => signature,
 871                 };
 872                 let message = TaggedHash::new(SIGNATURE_TAG, &bytes);
 873                 merkle::verify_signature(&signature, &message, contents.payer_id)?;
 874
 875                 Ok(InvoiceRequest { bytes, contents, signature })
 876         }
 877 }
 878
 879 impl TryFrom<PartialInvoiceRequestTlvStream> for InvoiceRequestContents {
 880         type Error = Bolt12SemanticError;
 881
 882         fn try_from(tlv_stream: PartialInvoiceRequestTlvStream) -> Result<Self, Self::Error> {
 883                 let (
 884                         PayerTlvStream { metadata },
 885                         offer_tlv_stream,
 886                         InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
 887                 ) = tlv_stream;
 888
 889                 let payer = match metadata {
 890                         None => return Err(Bolt12SemanticError::MissingPayerMetadata),
 891                         Some(metadata) => PayerContents(Metadata::Bytes(metadata)),
 892                 };
 893                 let offer = OfferContents::try_from(offer_tlv_stream)?;
 894
 895                 if !offer.supports_chain(chain.unwrap_or_else(|| offer.implied_chain())) {
 896                         return Err(Bolt12SemanticError::UnsupportedChain);
 897                 }
 898
 899                 if offer.amount().is_none() && amount.is_none() {
 900                         return Err(Bolt12SemanticError::MissingAmount);
 901                 }
 902
 903                 offer.check_quantity(quantity)?;
 904                 offer.check_amount_msats_for_quantity(amount, quantity)?;
 905
 906                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
 907
 908                 let payer_id = match payer_id {
 909                         None => return Err(Bolt12SemanticError::MissingPayerId),
 910                         Some(payer_id) => payer_id,
 911                 };
 912
 913                 Ok(InvoiceRequestContents {
 914                         inner: InvoiceRequestContentsWithoutPayerId {
 915                                 payer, offer, chain, amount_msats: amount, features, quantity, payer_note,
 916                         },
 917                         payer_id,
 918                 })
 919         }
 920 }
 921
 922 #[cfg(test)]
 923 mod tests {
 924         use super::{InvoiceRequest, InvoiceRequestTlvStreamRef, SIGNATURE_TAG, UnsignedInvoiceRequest};
 925
 926         use bitcoin::blockdata::constants::ChainHash;
 927         use bitcoin::network::constants::Network;
 928         use bitcoin::secp256k1::{KeyPair, Secp256k1, SecretKey, self};
 929         use core::convert::{Infallible, TryFrom};
 930         use core::num::NonZeroU64;
 931         #[cfg(feature = "std")]
 932         use core::time::Duration;
 933         use crate::sign::KeyMaterial;
 934         use crate::ln::channelmanager::PaymentId;
 935         use crate::ln::features::{InvoiceRequestFeatures, OfferFeatures};
 936         use crate::ln::inbound_payment::ExpandedKey;
 937         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 938         use crate::offers::invoice::{Bolt12Invoice, SIGNATURE_TAG as INVOICE_SIGNATURE_TAG};
 939         use crate::offers::merkle::{SignError, SignatureTlvStreamRef, TaggedHash, self};
 940         use crate::offers::offer::{Amount, OfferTlvStreamRef, Quantity};
 941         #[cfg(not(c_bindings))]
 942         use {
 943                 crate::offers::offer::OfferBuilder,
 944         };
 945         #[cfg(c_bindings)]
 946         use {
 947                 crate::offers::offer::OfferWithExplicitMetadataBuilder as OfferBuilder,
 948         };
 949         use crate::offers::parse::{Bolt12ParseError, Bolt12SemanticError};
 950         use crate::offers::payer::PayerTlvStreamRef;
 951         use crate::offers::test_utils::*;
 952         use crate::util::ser::{BigSize, Writeable};
 953         use crate::util::string::PrintableString;
 954
 955         #[test]
 956         fn builds_invoice_request_with_defaults() {
 957                 let unsigned_invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 958                         .amount_msats(1000)
 959                         .build().unwrap()
 960                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 961                         .build().unwrap();
 962
 963                 let mut buffer = Vec::new();
 964                 unsigned_invoice_request.write(&mut buffer).unwrap();
 965
 966                 assert_eq!(unsigned_invoice_request.bytes, buffer.as_slice());
 967                 assert_eq!(unsigned_invoice_request.payer_metadata(), &[1; 32]);
 968                 assert_eq!(unsigned_invoice_request.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
 969                 assert_eq!(unsigned_invoice_request.metadata(), None);
 970                 assert_eq!(unsigned_invoice_request.amount(), Some(&Amount::Bitcoin { amount_msats: 1000 }));
 971                 assert_eq!(unsigned_invoice_request.description(), PrintableString("foo"));
 972                 assert_eq!(unsigned_invoice_request.offer_features(), &OfferFeatures::empty());
 973                 assert_eq!(unsigned_invoice_request.absolute_expiry(), None);
 974                 assert_eq!(unsigned_invoice_request.paths(), &[]);
 975                 assert_eq!(unsigned_invoice_request.issuer(), None);
 976                 assert_eq!(unsigned_invoice_request.supported_quantity(), Quantity::One);
 977                 assert_eq!(unsigned_invoice_request.signing_pubkey(), recipient_pubkey());
 978                 assert_eq!(unsigned_invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
 979                 assert_eq!(unsigned_invoice_request.amount_msats(), None);
 980                 assert_eq!(unsigned_invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
 981                 assert_eq!(unsigned_invoice_request.quantity(), None);
 982                 assert_eq!(unsigned_invoice_request.payer_id(), payer_pubkey());
 983                 assert_eq!(unsigned_invoice_request.payer_note(), None);
 984
 985                 match UnsignedInvoiceRequest::try_from(buffer) {
 986                         Err(e) => panic!("error parsing unsigned invoice request: {:?}", e),
 987                         Ok(parsed) => {
 988                                 assert_eq!(parsed.bytes, unsigned_invoice_request.bytes);
 989                                 assert_eq!(parsed.tagged_hash, unsigned_invoice_request.tagged_hash);
 990                         },
 991                 }
 992
 993                 let invoice_request = unsigned_invoice_request.sign(payer_sign).unwrap();
 994
 995                 let mut buffer = Vec::new();
 996                 invoice_request.write(&mut buffer).unwrap();
 997
 998                 assert_eq!(invoice_request.bytes, buffer.as_slice());
 999                 assert_eq!(invoice_request.payer_metadata(), &[1; 32]);
1000                 assert_eq!(invoice_request.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
1001                 assert_eq!(invoice_request.metadata(), None);
1002                 assert_eq!(invoice_request.amount(), Some(&Amount::Bitcoin { amount_msats: 1000 }));
1003                 assert_eq!(invoice_request.description(), PrintableString("foo"));
1004                 assert_eq!(invoice_request.offer_features(), &OfferFeatures::empty());
1005                 assert_eq!(invoice_request.absolute_expiry(), None);
1006                 assert_eq!(invoice_request.paths(), &[]);
1007                 assert_eq!(invoice_request.issuer(), None);
1008                 assert_eq!(invoice_request.supported_quantity(), Quantity::One);
1009                 assert_eq!(invoice_request.signing_pubkey(), recipient_pubkey());
1010                 assert_eq!(invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
1011                 assert_eq!(invoice_request.amount_msats(), None);
1012                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
1013                 assert_eq!(invoice_request.quantity(), None);
1014                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
1015                 assert_eq!(invoice_request.payer_note(), None);
1016
1017                 let message = TaggedHash::new(SIGNATURE_TAG, &invoice_request.bytes);
1018                 assert!(merkle::verify_signature(&invoice_request.signature, &message, payer_pubkey()).is_ok());
1019
1020                 assert_eq!(
1021                         invoice_request.as_tlv_stream(),
1022                         (
1023                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
1024                                 OfferTlvStreamRef {
1025                                         chains: None,
1026                                         metadata: None,
1027                                         currency: None,
1028                                         amount: Some(1000),
1029                                         description: Some(&String::from("foo")),
1030                                         features: None,
1031                                         absolute_expiry: None,
1032                                         paths: None,
1033                                         issuer: None,
1034                                         quantity_max: None,
1035                                         node_id: Some(&recipient_pubkey()),
1036                                 },
1037                                 InvoiceRequestTlvStreamRef {
1038                                         chain: None,
1039                                         amount: None,
1040                                         features: None,
1041                                         quantity: None,
1042                                         payer_id: Some(&payer_pubkey()),
1043                                         payer_note: None,
1044                                 },
1045                                 SignatureTlvStreamRef { signature: Some(&invoice_request.signature()) },
1046                         ),
1047                 );
1048
1049                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1050                         panic!("error parsing invoice request: {:?}", e);
1051                 }
1052         }
1053
1054         #[cfg(feature = "std")]
1055         #[test]
1056         fn builds_invoice_request_from_offer_with_expiration() {
1057                 let future_expiry = Duration::from_secs(u64::max_value());
1058                 let past_expiry = Duration::from_secs(0);
1059
1060                 if let Err(e) = OfferBuilder::new("foo".into(), recipient_pubkey())
1061                         .amount_msats(1000)
1062                         .absolute_expiry(future_expiry)
1063                         .build().unwrap()
1064                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1065                         .build()
1066                 {
1067                         panic!("error building invoice_request: {:?}", e);
1068                 }
1069
1070                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1071                         .amount_msats(1000)
1072                         .absolute_expiry(past_expiry)
1073                         .build().unwrap()
1074                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1075                         .build()
1076                 {
1077                         Ok(_) => panic!("expected error"),
1078                         Err(e) => assert_eq!(e, Bolt12SemanticError::AlreadyExpired),
1079                 }
1080         }
1081
1082         #[test]
1083         fn builds_invoice_request_with_derived_metadata() {
1084                 let payer_id = payer_pubkey();
1085                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1086                 let entropy = FixedEntropy {};
1087                 let secp_ctx = Secp256k1::new();
1088                 let payment_id = PaymentId([1; 32]);
1089
1090                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1091                         .amount_msats(1000)
1092                         .build().unwrap();
1093                 let invoice_request = offer
1094                         .request_invoice_deriving_metadata(payer_id, &expanded_key, &entropy, payment_id)
1095                         .unwrap()
1096                         .build().unwrap()
1097                         .sign(payer_sign).unwrap();
1098                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
1099
1100                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
1101                         .unwrap()
1102                         .build().unwrap()
1103                         .sign(recipient_sign).unwrap();
1104                 match invoice.verify(&expanded_key, &secp_ctx) {
1105                         Ok(payment_id) => assert_eq!(payment_id, PaymentId([1; 32])),
1106                         Err(()) => panic!("verification failed"),
1107                 }
1108
1109                 // Fails verification with altered fields
1110                 let (
1111                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
1112                         mut invoice_tlv_stream, mut signature_tlv_stream
1113                 ) = invoice.as_tlv_stream();
1114                 invoice_request_tlv_stream.amount = Some(2000);
1115                 invoice_tlv_stream.amount = Some(2000);
1116
1117                 let tlv_stream =
1118                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1119                 let mut bytes = Vec::new();
1120                 tlv_stream.write(&mut bytes).unwrap();
1121
1122                 let message = TaggedHash::new(INVOICE_SIGNATURE_TAG, &bytes);
1123                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1124                 signature_tlv_stream.signature = Some(&signature);
1125
1126                 let mut encoded_invoice = bytes;
1127                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1128
1129                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1130                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1131
1132                 // Fails verification with altered metadata
1133                 let (
1134                         mut payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream,
1135                         mut signature_tlv_stream
1136                 ) = invoice.as_tlv_stream();
1137                 let metadata = payer_tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1138                 payer_tlv_stream.metadata = Some(&metadata);
1139
1140                 let tlv_stream =
1141                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1142                 let mut bytes = Vec::new();
1143                 tlv_stream.write(&mut bytes).unwrap();
1144
1145                 let message = TaggedHash::new(INVOICE_SIGNATURE_TAG, &bytes);
1146                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1147                 signature_tlv_stream.signature = Some(&signature);
1148
1149                 let mut encoded_invoice = bytes;
1150                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1151
1152                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1153                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1154         }
1155
1156         #[test]
1157         fn builds_invoice_request_with_derived_payer_id() {
1158                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1159                 let entropy = FixedEntropy {};
1160                 let secp_ctx = Secp256k1::new();
1161                 let payment_id = PaymentId([1; 32]);
1162
1163                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1164                         .amount_msats(1000)
1165                         .build().unwrap();
1166                 let invoice_request = offer
1167                         .request_invoice_deriving_payer_id(&expanded_key, &entropy, &secp_ctx, payment_id)
1168                         .unwrap()
1169                         .build_and_sign()
1170                         .unwrap();
1171
1172                 let invoice = invoice_request.respond_with_no_std(payment_paths(), payment_hash(), now())
1173                         .unwrap()
1174                         .build().unwrap()
1175                         .sign(recipient_sign).unwrap();
1176                 match invoice.verify(&expanded_key, &secp_ctx) {
1177                         Ok(payment_id) => assert_eq!(payment_id, PaymentId([1; 32])),
1178                         Err(()) => panic!("verification failed"),
1179                 }
1180
1181                 // Fails verification with altered fields
1182                 let (
1183                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream,
1184                         mut invoice_tlv_stream, mut signature_tlv_stream
1185                 ) = invoice.as_tlv_stream();
1186                 invoice_request_tlv_stream.amount = Some(2000);
1187                 invoice_tlv_stream.amount = Some(2000);
1188
1189                 let tlv_stream =
1190                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1191                 let mut bytes = Vec::new();
1192                 tlv_stream.write(&mut bytes).unwrap();
1193
1194                 let message = TaggedHash::new(INVOICE_SIGNATURE_TAG, &bytes);
1195                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1196                 signature_tlv_stream.signature = Some(&signature);
1197
1198                 let mut encoded_invoice = bytes;
1199                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1200
1201                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1202                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1203
1204                 // Fails verification with altered payer id
1205                 let (
1206                         payer_tlv_stream, offer_tlv_stream, mut invoice_request_tlv_stream, invoice_tlv_stream,
1207                         mut signature_tlv_stream
1208                 ) = invoice.as_tlv_stream();
1209                 let payer_id = pubkey(1);
1210                 invoice_request_tlv_stream.payer_id = Some(&payer_id);
1211
1212                 let tlv_stream =
1213                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, invoice_tlv_stream);
1214                 let mut bytes = Vec::new();
1215                 tlv_stream.write(&mut bytes).unwrap();
1216
1217                 let message = TaggedHash::new(INVOICE_SIGNATURE_TAG, &bytes);
1218                 let signature = merkle::sign_message(recipient_sign, &message, recipient_pubkey()).unwrap();
1219                 signature_tlv_stream.signature = Some(&signature);
1220
1221                 let mut encoded_invoice = bytes;
1222                 signature_tlv_stream.write(&mut encoded_invoice).unwrap();
1223
1224                 let invoice = Bolt12Invoice::try_from(encoded_invoice).unwrap();
1225                 assert!(invoice.verify(&expanded_key, &secp_ctx).is_err());
1226         }
1227
1228         #[test]
1229         fn builds_invoice_request_with_chain() {
1230                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
1231                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
1232
1233                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1234                         .amount_msats(1000)
1235                         .build().unwrap()
1236                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1237                         .chain(Network::Bitcoin).unwrap()
1238                         .build().unwrap()
1239                         .sign(payer_sign).unwrap();
1240                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1241                 assert_eq!(invoice_request.chain(), mainnet);
1242                 assert_eq!(tlv_stream.chain, None);
1243
1244                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1245                         .amount_msats(1000)
1246                         .chain(Network::Testnet)
1247                         .build().unwrap()
1248                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1249                         .chain(Network::Testnet).unwrap()
1250                         .build().unwrap()
1251                         .sign(payer_sign).unwrap();
1252                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1253                 assert_eq!(invoice_request.chain(), testnet);
1254                 assert_eq!(tlv_stream.chain, Some(&testnet));
1255
1256                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1257                         .amount_msats(1000)
1258                         .chain(Network::Bitcoin)
1259                         .chain(Network::Testnet)
1260                         .build().unwrap()
1261                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1262                         .chain(Network::Bitcoin).unwrap()
1263                         .build().unwrap()
1264                         .sign(payer_sign).unwrap();
1265                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1266                 assert_eq!(invoice_request.chain(), mainnet);
1267                 assert_eq!(tlv_stream.chain, None);
1268
1269                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1270                         .amount_msats(1000)
1271                         .chain(Network::Bitcoin)
1272                         .chain(Network::Testnet)
1273                         .build().unwrap()
1274                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1275                         .chain(Network::Bitcoin).unwrap()
1276                         .chain(Network::Testnet).unwrap()
1277                         .build().unwrap()
1278                         .sign(payer_sign).unwrap();
1279                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1280                 assert_eq!(invoice_request.chain(), testnet);
1281                 assert_eq!(tlv_stream.chain, Some(&testnet));
1282
1283                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1284                         .amount_msats(1000)
1285                         .chain(Network::Testnet)
1286                         .build().unwrap()
1287                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1288                         .chain(Network::Bitcoin)
1289                 {
1290                         Ok(_) => panic!("expected error"),
1291                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
1292                 }
1293
1294                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1295                         .amount_msats(1000)
1296                         .chain(Network::Testnet)
1297                         .build().unwrap()
1298                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1299                         .build()
1300                 {
1301                         Ok(_) => panic!("expected error"),
1302                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnsupportedChain),
1303                 }
1304         }
1305
1306         #[test]
1307         fn builds_invoice_request_with_amount() {
1308                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1309                         .amount_msats(1000)
1310                         .build().unwrap()
1311                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1312                         .amount_msats(1000).unwrap()
1313                         .build().unwrap()
1314                         .sign(payer_sign).unwrap();
1315                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1316                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1317                 assert_eq!(tlv_stream.amount, Some(1000));
1318
1319                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1320                         .amount_msats(1000)
1321                         .build().unwrap()
1322                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1323                         .amount_msats(1001).unwrap()
1324                         .amount_msats(1000).unwrap()
1325                         .build().unwrap()
1326                         .sign(payer_sign).unwrap();
1327                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1328                 assert_eq!(invoice_request.amount_msats(), Some(1000));
1329                 assert_eq!(tlv_stream.amount, Some(1000));
1330
1331                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1332                         .amount_msats(1000)
1333                         .build().unwrap()
1334                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1335                         .amount_msats(1001).unwrap()
1336                         .build().unwrap()
1337                         .sign(payer_sign).unwrap();
1338                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1339                 assert_eq!(invoice_request.amount_msats(), Some(1001));
1340                 assert_eq!(tlv_stream.amount, Some(1001));
1341
1342                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1343                         .amount_msats(1000)
1344                         .build().unwrap()
1345                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1346                         .amount_msats(999)
1347                 {
1348                         Ok(_) => panic!("expected error"),
1349                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1350                 }
1351
1352                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1353                         .amount_msats(1000)
1354                         .supported_quantity(Quantity::Unbounded)
1355                         .build().unwrap()
1356                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1357                         .quantity(2).unwrap()
1358                         .amount_msats(1000)
1359                 {
1360                         Ok(_) => panic!("expected error"),
1361                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1362                 }
1363
1364                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1365                         .amount_msats(1000)
1366                         .build().unwrap()
1367                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1368                         .amount_msats(MAX_VALUE_MSAT + 1)
1369                 {
1370                         Ok(_) => panic!("expected error"),
1371                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1372                 }
1373
1374                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1375                         .amount_msats(1000)
1376                         .supported_quantity(Quantity::Unbounded)
1377                         .build().unwrap()
1378                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1379                         .amount_msats(1000).unwrap()
1380                         .quantity(2).unwrap()
1381                         .build()
1382                 {
1383                         Ok(_) => panic!("expected error"),
1384                         Err(e) => assert_eq!(e, Bolt12SemanticError::InsufficientAmount),
1385                 }
1386
1387                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1388                         .build().unwrap()
1389                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1390                         .build()
1391                 {
1392                         Ok(_) => panic!("expected error"),
1393                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingAmount),
1394                 }
1395
1396                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1397                         .amount_msats(1000)
1398                         .supported_quantity(Quantity::Unbounded)
1399                         .build().unwrap()
1400                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1401                         .quantity(u64::max_value()).unwrap()
1402                         .build()
1403                 {
1404                         Ok(_) => panic!("expected error"),
1405                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidAmount),
1406                 }
1407         }
1408
1409         #[test]
1410         fn builds_invoice_request_with_features() {
1411                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1412                         .amount_msats(1000)
1413                         .build().unwrap()
1414                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1415                         .features_unchecked(InvoiceRequestFeatures::unknown())
1416                         .build().unwrap()
1417                         .sign(payer_sign).unwrap();
1418                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1419                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::unknown());
1420                 assert_eq!(tlv_stream.features, Some(&InvoiceRequestFeatures::unknown()));
1421
1422                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1423                         .amount_msats(1000)
1424                         .build().unwrap()
1425                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1426                         .features_unchecked(InvoiceRequestFeatures::unknown())
1427                         .features_unchecked(InvoiceRequestFeatures::empty())
1428                         .build().unwrap()
1429                         .sign(payer_sign).unwrap();
1430                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1431                 assert_eq!(invoice_request.invoice_request_features(), &InvoiceRequestFeatures::empty());
1432                 assert_eq!(tlv_stream.features, None);
1433         }
1434
1435         #[test]
1436         fn builds_invoice_request_with_quantity() {
1437                 let one = NonZeroU64::new(1).unwrap();
1438                 let ten = NonZeroU64::new(10).unwrap();
1439
1440                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1441                         .amount_msats(1000)
1442                         .supported_quantity(Quantity::One)
1443                         .build().unwrap()
1444                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1445                         .build().unwrap()
1446                         .sign(payer_sign).unwrap();
1447                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1448                 assert_eq!(invoice_request.quantity(), None);
1449                 assert_eq!(tlv_stream.quantity, None);
1450
1451                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1452                         .amount_msats(1000)
1453                         .supported_quantity(Quantity::One)
1454                         .build().unwrap()
1455                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1456                         .amount_msats(2_000).unwrap()
1457                         .quantity(2)
1458                 {
1459                         Ok(_) => panic!("expected error"),
1460                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnexpectedQuantity),
1461                 }
1462
1463                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1464                         .amount_msats(1000)
1465                         .supported_quantity(Quantity::Bounded(ten))
1466                         .build().unwrap()
1467                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1468                         .amount_msats(10_000).unwrap()
1469                         .quantity(10).unwrap()
1470                         .build().unwrap()
1471                         .sign(payer_sign).unwrap();
1472                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1473                 assert_eq!(invoice_request.amount_msats(), Some(10_000));
1474                 assert_eq!(tlv_stream.amount, Some(10_000));
1475
1476                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1477                         .amount_msats(1000)
1478                         .supported_quantity(Quantity::Bounded(ten))
1479                         .build().unwrap()
1480                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1481                         .amount_msats(11_000).unwrap()
1482                         .quantity(11)
1483                 {
1484                         Ok(_) => panic!("expected error"),
1485                         Err(e) => assert_eq!(e, Bolt12SemanticError::InvalidQuantity),
1486                 }
1487
1488                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1489                         .amount_msats(1000)
1490                         .supported_quantity(Quantity::Unbounded)
1491                         .build().unwrap()
1492                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1493                         .amount_msats(2_000).unwrap()
1494                         .quantity(2).unwrap()
1495                         .build().unwrap()
1496                         .sign(payer_sign).unwrap();
1497                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1498                 assert_eq!(invoice_request.amount_msats(), Some(2_000));
1499                 assert_eq!(tlv_stream.amount, Some(2_000));
1500
1501                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1502                         .amount_msats(1000)
1503                         .supported_quantity(Quantity::Unbounded)
1504                         .build().unwrap()
1505                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1506                         .build()
1507                 {
1508                         Ok(_) => panic!("expected error"),
1509                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
1510                 }
1511
1512                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1513                         .amount_msats(1000)
1514                         .supported_quantity(Quantity::Bounded(one))
1515                         .build().unwrap()
1516                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1517                         .build()
1518                 {
1519                         Ok(_) => panic!("expected error"),
1520                         Err(e) => assert_eq!(e, Bolt12SemanticError::MissingQuantity),
1521                 }
1522         }
1523
1524         #[test]
1525         fn builds_invoice_request_with_payer_note() {
1526                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1527                         .amount_msats(1000)
1528                         .build().unwrap()
1529                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1530                         .payer_note("bar".into())
1531                         .build().unwrap()
1532                         .sign(payer_sign).unwrap();
1533                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1534                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("bar")));
1535                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
1536
1537                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1538                         .amount_msats(1000)
1539                         .build().unwrap()
1540                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1541                         .payer_note("bar".into())
1542                         .payer_note("baz".into())
1543                         .build().unwrap()
1544                         .sign(payer_sign).unwrap();
1545                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
1546                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("baz")));
1547                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
1548         }
1549
1550         #[test]
1551         fn fails_signing_invoice_request() {
1552                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1553                         .amount_msats(1000)
1554                         .build().unwrap()
1555                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1556                         .build().unwrap()
1557                         .sign(|_| Err(()))
1558                 {
1559                         Ok(_) => panic!("expected error"),
1560                         Err(e) => assert_eq!(e, SignError::Signing(())),
1561                 }
1562
1563                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1564                         .amount_msats(1000)
1565                         .build().unwrap()
1566                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1567                         .build().unwrap()
1568                         .sign(recipient_sign)
1569                 {
1570                         Ok(_) => panic!("expected error"),
1571                         Err(e) => assert_eq!(e, SignError::Verification(secp256k1::Error::InvalidSignature)),
1572                 }
1573         }
1574
1575         #[test]
1576         fn fails_responding_with_unknown_required_features() {
1577                 match OfferBuilder::new("foo".into(), recipient_pubkey())
1578                         .amount_msats(1000)
1579                         .build().unwrap()
1580                         .request_invoice(vec![42; 32], payer_pubkey()).unwrap()
1581                         .features_unchecked(InvoiceRequestFeatures::unknown())
1582                         .build().unwrap()
1583                         .sign(payer_sign).unwrap()
1584                         .respond_with_no_std(payment_paths(), payment_hash(), now())
1585                 {
1586                         Ok(_) => panic!("expected error"),
1587                         Err(e) => assert_eq!(e, Bolt12SemanticError::UnknownRequiredFeatures),
1588                 }
1589         }
1590
1591         #[test]
1592         fn parses_invoice_request_with_metadata() {
1593                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1594                         .amount_msats(1000)
1595                         .build().unwrap()
1596                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1597                         .build().unwrap()
1598                         .sign(payer_sign).unwrap();
1599
1600                 let mut buffer = Vec::new();
1601                 invoice_request.write(&mut buffer).unwrap();
1602
1603                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1604                         panic!("error parsing invoice_request: {:?}", e);
1605                 }
1606         }
1607
1608         #[test]
1609         fn parses_invoice_request_with_chain() {
1610                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1611                         .amount_msats(1000)
1612                         .build().unwrap()
1613                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1614                         .chain(Network::Bitcoin).unwrap()
1615                         .build().unwrap()
1616                         .sign(payer_sign).unwrap();
1617
1618                 let mut buffer = Vec::new();
1619                 invoice_request.write(&mut buffer).unwrap();
1620
1621                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1622                         panic!("error parsing invoice_request: {:?}", e);
1623                 }
1624
1625                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1626                         .amount_msats(1000)
1627                         .build().unwrap()
1628                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1629                         .chain_unchecked(Network::Testnet)
1630                         .build_unchecked()
1631                         .sign(payer_sign).unwrap();
1632
1633                 let mut buffer = Vec::new();
1634                 invoice_request.write(&mut buffer).unwrap();
1635
1636                 match InvoiceRequest::try_from(buffer) {
1637                         Ok(_) => panic!("expected error"),
1638                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnsupportedChain)),
1639                 }
1640         }
1641
1642         #[test]
1643         fn parses_invoice_request_with_amount() {
1644                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1645                         .amount_msats(1000)
1646                         .build().unwrap()
1647                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1648                         .build().unwrap()
1649                         .sign(payer_sign).unwrap();
1650
1651                 let mut buffer = Vec::new();
1652                 invoice_request.write(&mut buffer).unwrap();
1653
1654                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1655                         panic!("error parsing invoice_request: {:?}", e);
1656                 }
1657
1658                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1659                         .build().unwrap()
1660                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1661                         .amount_msats(1000).unwrap()
1662                         .build().unwrap()
1663                         .sign(payer_sign).unwrap();
1664
1665                 let mut buffer = Vec::new();
1666                 invoice_request.write(&mut buffer).unwrap();
1667
1668                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1669                         panic!("error parsing invoice_request: {:?}", e);
1670                 }
1671
1672                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1673                         .build().unwrap()
1674                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1675                         .build_unchecked()
1676                         .sign(payer_sign).unwrap();
1677
1678                 let mut buffer = Vec::new();
1679                 invoice_request.write(&mut buffer).unwrap();
1680
1681                 match InvoiceRequest::try_from(buffer) {
1682                         Ok(_) => panic!("expected error"),
1683                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingAmount)),
1684                 }
1685
1686                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1687                         .amount_msats(1000)
1688                         .build().unwrap()
1689                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1690                         .amount_msats_unchecked(999)
1691                         .build_unchecked()
1692                         .sign(payer_sign).unwrap();
1693
1694                 let mut buffer = Vec::new();
1695                 invoice_request.write(&mut buffer).unwrap();
1696
1697                 match InvoiceRequest::try_from(buffer) {
1698                         Ok(_) => panic!("expected error"),
1699                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InsufficientAmount)),
1700                 }
1701
1702                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1703                         .amount(Amount::Currency { iso4217_code: *b"USD", amount: 1000 })
1704                         .build_unchecked()
1705                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1706                         .build_unchecked()
1707                         .sign(payer_sign).unwrap();
1708
1709                 let mut buffer = Vec::new();
1710                 invoice_request.write(&mut buffer).unwrap();
1711
1712                 match InvoiceRequest::try_from(buffer) {
1713                         Ok(_) => panic!("expected error"),
1714                         Err(e) => {
1715                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnsupportedCurrency));
1716                         },
1717                 }
1718
1719                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1720                         .amount_msats(1000)
1721                         .supported_quantity(Quantity::Unbounded)
1722                         .build().unwrap()
1723                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1724                         .quantity(u64::max_value()).unwrap()
1725                         .build_unchecked()
1726                         .sign(payer_sign).unwrap();
1727
1728                 let mut buffer = Vec::new();
1729                 invoice_request.write(&mut buffer).unwrap();
1730
1731                 match InvoiceRequest::try_from(buffer) {
1732                         Ok(_) => panic!("expected error"),
1733                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidAmount)),
1734                 }
1735         }
1736
1737         #[test]
1738         fn parses_invoice_request_with_quantity() {
1739                 let one = NonZeroU64::new(1).unwrap();
1740                 let ten = NonZeroU64::new(10).unwrap();
1741
1742                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1743                         .amount_msats(1000)
1744                         .supported_quantity(Quantity::One)
1745                         .build().unwrap()
1746                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1747                         .build().unwrap()
1748                         .sign(payer_sign).unwrap();
1749
1750                 let mut buffer = Vec::new();
1751                 invoice_request.write(&mut buffer).unwrap();
1752
1753                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1754                         panic!("error parsing invoice_request: {:?}", e);
1755                 }
1756
1757                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1758                         .amount_msats(1000)
1759                         .supported_quantity(Quantity::One)
1760                         .build().unwrap()
1761                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1762                         .amount_msats(2_000).unwrap()
1763                         .quantity_unchecked(2)
1764                         .build_unchecked()
1765                         .sign(payer_sign).unwrap();
1766
1767                 let mut buffer = Vec::new();
1768                 invoice_request.write(&mut buffer).unwrap();
1769
1770                 match InvoiceRequest::try_from(buffer) {
1771                         Ok(_) => panic!("expected error"),
1772                         Err(e) => {
1773                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::UnexpectedQuantity));
1774                         },
1775                 }
1776
1777                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1778                         .amount_msats(1000)
1779                         .supported_quantity(Quantity::Bounded(ten))
1780                         .build().unwrap()
1781                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1782                         .amount_msats(10_000).unwrap()
1783                         .quantity(10).unwrap()
1784                         .build().unwrap()
1785                         .sign(payer_sign).unwrap();
1786
1787                 let mut buffer = Vec::new();
1788                 invoice_request.write(&mut buffer).unwrap();
1789
1790                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1791                         panic!("error parsing invoice_request: {:?}", e);
1792                 }
1793
1794                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1795                         .amount_msats(1000)
1796                         .supported_quantity(Quantity::Bounded(ten))
1797                         .build().unwrap()
1798                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1799                         .amount_msats(11_000).unwrap()
1800                         .quantity_unchecked(11)
1801                         .build_unchecked()
1802                         .sign(payer_sign).unwrap();
1803
1804                 let mut buffer = Vec::new();
1805                 invoice_request.write(&mut buffer).unwrap();
1806
1807                 match InvoiceRequest::try_from(buffer) {
1808                         Ok(_) => panic!("expected error"),
1809                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::InvalidQuantity)),
1810                 }
1811
1812                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1813                         .amount_msats(1000)
1814                         .supported_quantity(Quantity::Unbounded)
1815                         .build().unwrap()
1816                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1817                         .amount_msats(2_000).unwrap()
1818                         .quantity(2).unwrap()
1819                         .build().unwrap()
1820                         .sign(payer_sign).unwrap();
1821
1822                 let mut buffer = Vec::new();
1823                 invoice_request.write(&mut buffer).unwrap();
1824
1825                 if let Err(e) = InvoiceRequest::try_from(buffer) {
1826                         panic!("error parsing invoice_request: {:?}", e);
1827                 }
1828
1829                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1830                         .amount_msats(1000)
1831                         .supported_quantity(Quantity::Unbounded)
1832                         .build().unwrap()
1833                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1834                         .build_unchecked()
1835                         .sign(payer_sign).unwrap();
1836
1837                 let mut buffer = Vec::new();
1838                 invoice_request.write(&mut buffer).unwrap();
1839
1840                 match InvoiceRequest::try_from(buffer) {
1841                         Ok(_) => panic!("expected error"),
1842                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
1843                 }
1844
1845                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1846                         .amount_msats(1000)
1847                         .supported_quantity(Quantity::Bounded(one))
1848                         .build().unwrap()
1849                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1850                         .build_unchecked()
1851                         .sign(payer_sign).unwrap();
1852
1853                 let mut buffer = Vec::new();
1854                 invoice_request.write(&mut buffer).unwrap();
1855
1856                 match InvoiceRequest::try_from(buffer) {
1857                         Ok(_) => panic!("expected error"),
1858                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingQuantity)),
1859                 }
1860         }
1861
1862         #[test]
1863         fn fails_parsing_invoice_request_without_metadata() {
1864                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1865                         .amount_msats(1000)
1866                         .build().unwrap();
1867                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1868                         .build().unwrap();
1869                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
1870                 tlv_stream.0.metadata = None;
1871
1872                 let mut buffer = Vec::new();
1873                 tlv_stream.write(&mut buffer).unwrap();
1874
1875                 match InvoiceRequest::try_from(buffer) {
1876                         Ok(_) => panic!("expected error"),
1877                         Err(e) => {
1878                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPayerMetadata));
1879                         },
1880                 }
1881         }
1882
1883         #[test]
1884         fn fails_parsing_invoice_request_without_payer_id() {
1885                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1886                         .amount_msats(1000)
1887                         .build().unwrap();
1888                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1889                         .build().unwrap();
1890                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
1891                 tlv_stream.2.payer_id = None;
1892
1893                 let mut buffer = Vec::new();
1894                 tlv_stream.write(&mut buffer).unwrap();
1895
1896                 match InvoiceRequest::try_from(buffer) {
1897                         Ok(_) => panic!("expected error"),
1898                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingPayerId)),
1899                 }
1900         }
1901
1902         #[test]
1903         fn fails_parsing_invoice_request_without_node_id() {
1904                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
1905                         .amount_msats(1000)
1906                         .build().unwrap();
1907                 let unsigned_invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1908                         .build().unwrap();
1909                 let mut tlv_stream = unsigned_invoice_request.contents.as_tlv_stream();
1910                 tlv_stream.1.node_id = None;
1911
1912                 let mut buffer = Vec::new();
1913                 tlv_stream.write(&mut buffer).unwrap();
1914
1915                 match InvoiceRequest::try_from(buffer) {
1916                         Ok(_) => panic!("expected error"),
1917                         Err(e) => {
1918                                 assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSigningPubkey));
1919                         },
1920                 }
1921         }
1922
1923         #[test]
1924         fn fails_parsing_invoice_request_without_signature() {
1925                 let mut buffer = Vec::new();
1926                 OfferBuilder::new("foo".into(), recipient_pubkey())
1927                         .amount_msats(1000)
1928                         .build().unwrap()
1929                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1930                         .build().unwrap()
1931                         .contents
1932                         .write(&mut buffer).unwrap();
1933
1934                 match InvoiceRequest::try_from(buffer) {
1935                         Ok(_) => panic!("expected error"),
1936                         Err(e) => assert_eq!(e, Bolt12ParseError::InvalidSemantics(Bolt12SemanticError::MissingSignature)),
1937                 }
1938         }
1939
1940         #[test]
1941         fn fails_parsing_invoice_request_with_invalid_signature() {
1942                 let mut invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
1943                         .amount_msats(1000)
1944                         .build().unwrap()
1945                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1946                         .build().unwrap()
1947                         .sign(payer_sign).unwrap();
1948                 let last_signature_byte = invoice_request.bytes.last_mut().unwrap();
1949                 *last_signature_byte = last_signature_byte.wrapping_add(1);
1950
1951                 let mut buffer = Vec::new();
1952                 invoice_request.write(&mut buffer).unwrap();
1953
1954                 match InvoiceRequest::try_from(buffer) {
1955                         Ok(_) => panic!("expected error"),
1956                         Err(e) => {
1957                                 assert_eq!(e, Bolt12ParseError::InvalidSignature(secp256k1::Error::InvalidSignature));
1958                         },
1959                 }
1960         }
1961
1962         #[test]
1963         fn fails_parsing_invoice_request_with_extra_tlv_records() {
1964                 let secp_ctx = Secp256k1::new();
1965                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1966                 let invoice_request = OfferBuilder::new("foo".into(), keys.public_key())
1967                         .amount_msats(1000)
1968                         .build().unwrap()
1969                         .request_invoice(vec![1; 32], keys.public_key()).unwrap()
1970                         .build().unwrap()
1971                         .sign::<_, Infallible>(
1972                                 |message| Ok(secp_ctx.sign_schnorr_no_aux_rand(message.as_ref().as_digest(), &keys))
1973                         )
1974                         .unwrap();
1975
1976                 let mut encoded_invoice_request = Vec::new();
1977                 invoice_request.write(&mut encoded_invoice_request).unwrap();
1978                 BigSize(1002).write(&mut encoded_invoice_request).unwrap();
1979                 BigSize(32).write(&mut encoded_invoice_request).unwrap();
1980                 [42u8; 32].write(&mut encoded_invoice_request).unwrap();
1981
1982                 match InvoiceRequest::try_from(encoded_invoice_request) {
1983                         Ok(_) => panic!("expected error"),
1984                         Err(e) => assert_eq!(e, Bolt12ParseError::Decode(DecodeError::InvalidValue)),
1985                 }
1986         }
1987 }