_ 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 either built from a parsed [`Offer`] as an "offer to be paid" or
  13 //! built directly as an "offer for money" (e.g., refund, ATM withdrawal). In the former case, it is
  14 //! typically constructed by a customer and sent to the merchant who had published the corresponding
  15 //! offer. In the latter case, an offer doesn't exist as a precursor to the request. Rather the
  16 //! merchant would typically construct the invoice request and present it to the customer.
  17 //!
  18 //! The recipient of the request responds with an `Invoice`.
  19 //!
  20 //! ```ignore
  21 //! extern crate bitcoin;
  22 //! extern crate lightning;
  23 //!
  24 //! use bitcoin::network::constants::Network;
  25 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
  26 //! use core::convert::Infallible;
  27 //! use lightning::ln::features::OfferFeatures;
  28 //! use lightning::offers::offer::Offer;
  29 //! use lightning::util::ser::Writeable;
  30 //!
  31 //! # fn parse() -> Result<(), lightning::offers::parse::ParseError> {
  32 //! let secp_ctx = Secp256k1::new();
  33 //! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32])?);
  34 //! let pubkey = PublicKey::from(keys);
  35 //! let mut buffer = Vec::new();
  36 //!
  37 //! // "offer to be paid" flow
  38 //! "lno1qcp4256ypq"
  39 //!     .parse::<Offer>()?
  40 //!     .request_invoice(vec![42; 64], pubkey)?
  41 //!     .chain(Network::Testnet)?
  42 //!     .amount_msats(1000)?
  43 //!     .quantity(5)?
  44 //!     .payer_note("foo".to_string())
  45 //!     .build()?
  46 //!     .sign::<_, Infallible>(|digest| Ok(secp_ctx.sign_schnorr_no_aux_rand(digest, &keys)))
  47 //!     .expect("failed verifying signature")
  48 //!     .write(&mut buffer)
  49 //!     .unwrap();
  50 //! # Ok(())
  51 //! # }
  52 //! ```
  53
  54 use bitcoin::blockdata::constants::ChainHash;
  55 use bitcoin::network::constants::Network;
  56 use bitcoin::secp256k1::{Message, PublicKey};
  57 use bitcoin::secp256k1::schnorr::Signature;
  58 use core::convert::TryFrom;
  59 use crate::io;
  60 use crate::ln::features::InvoiceRequestFeatures;
  61 use crate::ln::msgs::DecodeError;
  62 use crate::offers::merkle::{SignError, SignatureTlvStream, SignatureTlvStreamRef, self};
  63 use crate::offers::offer::{Offer, OfferContents, OfferTlvStream, OfferTlvStreamRef};
  64 use crate::offers::parse::{ParseError, ParsedMessage, SemanticError};
  65 use crate::offers::payer::{PayerContents, PayerTlvStream, PayerTlvStreamRef};
  66 use crate::util::ser::{HighZeroBytesDroppedBigSize, SeekReadable, WithoutLength, Writeable, Writer};
  67 use crate::util::string::PrintableString;
  68
  69 use crate::prelude::*;
  70
  71 const SIGNATURE_TAG: &'static str = concat!("lightning", "invoice_request", "signature");
  72
  73 /// Builds an [`InvoiceRequest`] from an [`Offer`] for the "offer to be paid" flow.
  74 ///
  75 /// See [module-level documentation] for usage.
  76 ///
  77 /// [module-level documentation]: self
  78 pub struct InvoiceRequestBuilder<'a> {
  79         offer: &'a Offer,
  80         invoice_request: InvoiceRequestContents,
  81 }
  82
  83 impl<'a> InvoiceRequestBuilder<'a> {
  84         pub(super) fn new(offer: &'a Offer, metadata: Vec<u8>, payer_id: PublicKey) -> Self {
  85                 Self {
  86                         offer,
  87                         invoice_request: InvoiceRequestContents {
  88                                 payer: PayerContents(metadata), offer: offer.contents.clone(), chain: None,
  89                                 amount_msats: None, features: InvoiceRequestFeatures::empty(), quantity: None,
  90                                 payer_id, payer_note: None,
  91                         },
  92                 }
  93         }
  94
  95         /// Sets the [`InvoiceRequest::chain`] of the given [`Network`] for paying an invoice. If not
  96         /// called, [`Network::Bitcoin`] is assumed. Errors if the chain for `network` is not supported
  97         /// by the offer.
  98         ///
  99         /// Successive calls to this method will override the previous setting.
 100         pub fn chain(mut self, network: Network) -> Result<Self, SemanticError> {
 101                 let chain = ChainHash::using_genesis_block(network);
 102                 if !self.offer.supports_chain(chain) {
 103                         return Err(SemanticError::UnsupportedChain);
 104                 }
 105
 106                 self.invoice_request.chain = Some(chain);
 107                 Ok(self)
 108         }
 109
 110         /// Sets the [`InvoiceRequest::amount_msats`] for paying an invoice. Errors if `amount_msats` is
 111         /// not at least the expected invoice amount (i.e., [`Offer::amount`] times [`quantity`]).
 112         ///
 113         /// Successive calls to this method will override the previous setting.
 114         ///
 115         /// [`quantity`]: Self::quantity
 116         pub fn amount_msats(mut self, amount_msats: u64) -> Result<Self, SemanticError> {
 117                 self.invoice_request.offer.check_amount_msats_for_quantity(
 118                         Some(amount_msats), self.invoice_request.quantity
 119                 )?;
 120                 self.invoice_request.amount_msats = Some(amount_msats);
 121                 Ok(self)
 122         }
 123
 124         /// Sets [`InvoiceRequest::quantity`] of items. If not set, `1` is assumed. Errors if `quantity`
 125         /// does not conform to [`Offer::is_valid_quantity`].
 126         ///
 127         /// Successive calls to this method will override the previous setting.
 128         pub fn quantity(mut self, quantity: u64) -> Result<Self, SemanticError> {
 129                 self.invoice_request.offer.check_quantity(Some(quantity))?;
 130                 self.invoice_request.quantity = Some(quantity);
 131                 Ok(self)
 132         }
 133
 134         /// Sets the [`InvoiceRequest::payer_note`].
 135         ///
 136         /// Successive calls to this method will override the previous setting.
 137         pub fn payer_note(mut self, payer_note: String) -> Self {
 138                 self.invoice_request.payer_note = Some(payer_note);
 139                 self
 140         }
 141
 142         /// Builds an unsigned [`InvoiceRequest`] after checking for valid semantics. It can be signed
 143         /// by [`UnsignedInvoiceRequest::sign`].
 144         pub fn build(mut self) -> Result<UnsignedInvoiceRequest<'a>, SemanticError> {
 145                 #[cfg(feature = "std")] {
 146                         if self.offer.is_expired() {
 147                                 return Err(SemanticError::AlreadyExpired);
 148                         }
 149                 }
 150
 151                 let chain = self.invoice_request.chain();
 152                 if !self.offer.supports_chain(chain) {
 153                         return Err(SemanticError::UnsupportedChain);
 154                 }
 155
 156                 if chain == self.offer.implied_chain() {
 157                         self.invoice_request.chain = None;
 158                 }
 159
 160                 if self.offer.amount().is_none() && self.invoice_request.amount_msats.is_none() {
 161                         return Err(SemanticError::MissingAmount);
 162                 }
 163
 164                 self.invoice_request.offer.check_quantity(self.invoice_request.quantity)?;
 165                 self.invoice_request.offer.check_amount_msats_for_quantity(
 166                         self.invoice_request.amount_msats, self.invoice_request.quantity
 167                 )?;
 168
 169                 let InvoiceRequestBuilder { offer, invoice_request } = self;
 170                 Ok(UnsignedInvoiceRequest { offer, invoice_request })
 171         }
 172 }
 173
 174 #[cfg(test)]
 175 impl<'a> InvoiceRequestBuilder<'a> {
 176         fn features_unchecked(mut self, features: InvoiceRequestFeatures) -> Self {
 177                 self.invoice_request.features = features;
 178                 self
 179         }
 180 }
 181
 182 /// A semantically valid [`InvoiceRequest`] that hasn't been signed.
 183 pub struct UnsignedInvoiceRequest<'a> {
 184         offer: &'a Offer,
 185         invoice_request: InvoiceRequestContents,
 186 }
 187
 188 impl<'a> UnsignedInvoiceRequest<'a> {
 189         /// Signs the invoice request using the given function.
 190         pub fn sign<F, E>(self, sign: F) -> Result<InvoiceRequest, SignError<E>>
 191         where
 192                 F: FnOnce(&Message) -> Result<Signature, E>
 193         {
 194                 // Use the offer bytes instead of the offer TLV stream as the offer may have contained
 195                 // unknown TLV records, which are not stored in `OfferContents`.
 196                 let (payer_tlv_stream, _offer_tlv_stream, invoice_request_tlv_stream) =
 197                         self.invoice_request.as_tlv_stream();
 198                 let offer_bytes = WithoutLength(&self.offer.bytes);
 199                 let unsigned_tlv_stream = (payer_tlv_stream, offer_bytes, invoice_request_tlv_stream);
 200
 201                 let mut bytes = Vec::new();
 202                 unsigned_tlv_stream.write(&mut bytes).unwrap();
 203
 204                 let pubkey = self.invoice_request.payer_id;
 205                 let signature = Some(merkle::sign_message(sign, SIGNATURE_TAG, &bytes, pubkey)?);
 206
 207                 // Append the signature TLV record to the bytes.
 208                 let signature_tlv_stream = SignatureTlvStreamRef {
 209                         signature: signature.as_ref(),
 210                 };
 211                 signature_tlv_stream.write(&mut bytes).unwrap();
 212
 213                 Ok(InvoiceRequest {
 214                         bytes,
 215                         contents: self.invoice_request,
 216                         signature,
 217                 })
 218         }
 219 }
 220
 221 /// An `InvoiceRequest` is a request for an `Invoice` formulated from an [`Offer`].
 222 ///
 223 /// An offer may provide choices such as quantity, amount, chain, features, etc. An invoice request
 224 /// specifies these such that its recipient can send an invoice for payment.
 225 ///
 226 /// [`Offer`]: crate::offers::offer::Offer
 227 #[derive(Clone, Debug)]
 228 pub struct InvoiceRequest {
 229         bytes: Vec<u8>,
 230         contents: InvoiceRequestContents,
 231         signature: Option<Signature>,
 232 }
 233
 234 /// The contents of an [`InvoiceRequest`], which may be shared with an `Invoice`.
 235 #[derive(Clone, Debug)]
 236 pub(super) struct InvoiceRequestContents {
 237         payer: PayerContents,
 238         offer: OfferContents,
 239         chain: Option<ChainHash>,
 240         amount_msats: Option<u64>,
 241         features: InvoiceRequestFeatures,
 242         quantity: Option<u64>,
 243         payer_id: PublicKey,
 244         payer_note: Option<String>,
 245 }
 246
 247 impl InvoiceRequest {
 248         /// An unpredictable series of bytes, typically containing information about the derivation of
 249         /// [`payer_id`].
 250         ///
 251         /// [`payer_id`]: Self::payer_id
 252         pub fn metadata(&self) -> &[u8] {
 253                 &self.contents.payer.0[..]
 254         }
 255
 256         /// A chain from [`Offer::chains`] that the offer is valid for.
 257         pub fn chain(&self) -> ChainHash {
 258                 self.contents.chain()
 259         }
 260
 261         /// The amount to pay in msats (i.e., the minimum lightning-payable unit for [`chain`]), which
 262         /// must be greater than or equal to [`Offer::amount`], converted if necessary.
 263         ///
 264         /// [`chain`]: Self::chain
 265         pub fn amount_msats(&self) -> Option<u64> {
 266                 self.contents.amount_msats
 267         }
 268
 269         /// Features for paying the invoice.
 270         pub fn features(&self) -> &InvoiceRequestFeatures {
 271                 &self.contents.features
 272         }
 273
 274         /// The quantity of the offer's item conforming to [`Offer::is_valid_quantity`].
 275         pub fn quantity(&self) -> Option<u64> {
 276                 self.contents.quantity
 277         }
 278
 279         /// A possibly transient pubkey used to sign the invoice request.
 280         pub fn payer_id(&self) -> PublicKey {
 281                 self.contents.payer_id
 282         }
 283
 284         /// A payer-provided note which will be seen by the recipient and reflected back in the invoice
 285         /// response.
 286         pub fn payer_note(&self) -> Option<PrintableString> {
 287                 self.contents.payer_note.as_ref().map(|payer_note| PrintableString(payer_note.as_str()))
 288         }
 289
 290         /// Signature of the invoice request using [`payer_id`].
 291         ///
 292         /// [`payer_id`]: Self::payer_id
 293         pub fn signature(&self) -> Option<Signature> {
 294                 self.signature
 295         }
 296
 297         #[cfg(test)]
 298         fn as_tlv_stream(&self) -> FullInvoiceRequestTlvStreamRef {
 299                 let (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream) =
 300                         self.contents.as_tlv_stream();
 301                 let signature_tlv_stream = SignatureTlvStreamRef {
 302                         signature: self.signature.as_ref(),
 303                 };
 304                 (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, signature_tlv_stream)
 305         }
 306 }
 307
 308 impl InvoiceRequestContents {
 309         fn chain(&self) -> ChainHash {
 310                 self.chain.unwrap_or_else(|| self.offer.implied_chain())
 311         }
 312
 313         pub(super) fn as_tlv_stream(&self) -> PartialInvoiceRequestTlvStreamRef {
 314                 let payer = PayerTlvStreamRef {
 315                         metadata: Some(&self.payer.0),
 316                 };
 317
 318                 let offer = self.offer.as_tlv_stream();
 319
 320                 let features = {
 321                         if self.features == InvoiceRequestFeatures::empty() { None }
 322                         else { Some(&self.features) }
 323                 };
 324
 325                 let invoice_request = InvoiceRequestTlvStreamRef {
 326                         chain: self.chain.as_ref(),
 327                         amount: self.amount_msats,
 328                         features,
 329                         quantity: self.quantity,
 330                         payer_id: Some(&self.payer_id),
 331                         payer_note: self.payer_note.as_ref(),
 332                 };
 333
 334                 (payer, offer, invoice_request)
 335         }
 336 }
 337
 338 impl Writeable for InvoiceRequest {
 339         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 340                 WithoutLength(&self.bytes).write(writer)
 341         }
 342 }
 343
 344 impl Writeable for InvoiceRequestContents {
 345         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 346                 self.as_tlv_stream().write(writer)
 347         }
 348 }
 349
 350 tlv_stream!(InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef, 80..160, {
 351         (80, chain: ChainHash),
 352         (82, amount: (u64, HighZeroBytesDroppedBigSize)),
 353         (84, features: InvoiceRequestFeatures),
 354         (86, quantity: (u64, HighZeroBytesDroppedBigSize)),
 355         (88, payer_id: PublicKey),
 356         (89, payer_note: (String, WithoutLength)),
 357 });
 358
 359 type FullInvoiceRequestTlvStream =
 360         (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream, SignatureTlvStream);
 361
 362 #[cfg(test)]
 363 type FullInvoiceRequestTlvStreamRef<'a> = (
 364         PayerTlvStreamRef<'a>,
 365         OfferTlvStreamRef<'a>,
 366         InvoiceRequestTlvStreamRef<'a>,
 367         SignatureTlvStreamRef<'a>,
 368 );
 369
 370 impl SeekReadable for FullInvoiceRequestTlvStream {
 371         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 372                 let payer = SeekReadable::read(r)?;
 373                 let offer = SeekReadable::read(r)?;
 374                 let invoice_request = SeekReadable::read(r)?;
 375                 let signature = SeekReadable::read(r)?;
 376
 377                 Ok((payer, offer, invoice_request, signature))
 378         }
 379 }
 380
 381 type PartialInvoiceRequestTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
 382
 383 type PartialInvoiceRequestTlvStreamRef<'a> = (
 384         PayerTlvStreamRef<'a>,
 385         OfferTlvStreamRef<'a>,
 386         InvoiceRequestTlvStreamRef<'a>,
 387 );
 388
 389 impl TryFrom<Vec<u8>> for InvoiceRequest {
 390         type Error = ParseError;
 391
 392         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 393                 let invoice_request = ParsedMessage::<FullInvoiceRequestTlvStream>::try_from(bytes)?;
 394                 let ParsedMessage { bytes, tlv_stream } = invoice_request;
 395                 let (
 396                         payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream,
 397                         SignatureTlvStream { signature },
 398                 ) = tlv_stream;
 399                 let contents = InvoiceRequestContents::try_from(
 400                         (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream)
 401                 )?;
 402
 403                 if let Some(signature) = &signature {
 404                         merkle::verify_signature(signature, SIGNATURE_TAG, &bytes, contents.payer_id)?;
 405                 }
 406
 407                 Ok(InvoiceRequest { bytes, contents, signature })
 408         }
 409 }
 410
 411 impl TryFrom<PartialInvoiceRequestTlvStream> for InvoiceRequestContents {
 412         type Error = SemanticError;
 413
 414         fn try_from(tlv_stream: PartialInvoiceRequestTlvStream) -> Result<Self, Self::Error> {
 415                 let (
 416                         PayerTlvStream { metadata },
 417                         offer_tlv_stream,
 418                         InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
 419                 ) = tlv_stream;
 420
 421                 let payer = match metadata {
 422                         None => return Err(SemanticError::MissingPayerMetadata),
 423                         Some(metadata) => PayerContents(metadata),
 424                 };
 425                 let offer = OfferContents::try_from(offer_tlv_stream)?;
 426
 427                 if !offer.supports_chain(chain.unwrap_or_else(|| offer.implied_chain())) {
 428                         return Err(SemanticError::UnsupportedChain);
 429                 }
 430
 431                 if offer.amount().is_none() && amount.is_none() {
 432                         return Err(SemanticError::MissingAmount);
 433                 }
 434
 435                 offer.check_quantity(quantity)?;
 436                 offer.check_amount_msats_for_quantity(amount, quantity)?;
 437
 438                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
 439
 440                 let payer_id = match payer_id {
 441                         None => return Err(SemanticError::MissingPayerId),
 442                         Some(payer_id) => payer_id,
 443                 };
 444
 445                 Ok(InvoiceRequestContents {
 446                         payer, offer, chain, amount_msats: amount, features, quantity, payer_id, payer_note,
 447                 })
 448         }
 449 }
 450
 451 #[cfg(test)]
 452 mod tests {
 453         use super::InvoiceRequest;
 454
 455         use bitcoin::blockdata::constants::ChainHash;
 456         use bitcoin::network::constants::Network;
 457         use bitcoin::secp256k1::{KeyPair, Message, PublicKey, Secp256k1, SecretKey, self};
 458         use bitcoin::secp256k1::schnorr::Signature;
 459         use core::convert::{Infallible, TryFrom};
 460         use core::num::NonZeroU64;
 461         #[cfg(feature = "std")]
 462         use core::time::Duration;
 463         use crate::ln::features::InvoiceRequestFeatures;
 464         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 465         use crate::offers::merkle::SignError;
 466         use crate::offers::offer::{OfferBuilder, Quantity};
 467         use crate::offers::parse::{ParseError, SemanticError};
 468         use crate::util::ser::{BigSize, Writeable};
 469         use crate::util::string::PrintableString;
 470
 471         fn payer_keys() -> KeyPair {
 472                 let secp_ctx = Secp256k1::new();
 473                 KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap())
 474         }
 475
 476         fn payer_sign(digest: &Message) -> Result<Signature, Infallible> {
 477                 let secp_ctx = Secp256k1::new();
 478                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
 479                 Ok(secp_ctx.sign_schnorr_no_aux_rand(digest, &keys))
 480         }
 481
 482         fn payer_pubkey() -> PublicKey {
 483                 payer_keys().public_key()
 484         }
 485
 486         fn recipient_sign(digest: &Message) -> Result<Signature, Infallible> {
 487                 let secp_ctx = Secp256k1::new();
 488                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[43; 32]).unwrap());
 489                 Ok(secp_ctx.sign_schnorr_no_aux_rand(digest, &keys))
 490         }
 491
 492         fn recipient_pubkey() -> PublicKey {
 493                 let secp_ctx = Secp256k1::new();
 494                 KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[43; 32]).unwrap()).public_key()
 495         }
 496
 497         #[test]
 498         fn builds_invoice_request_with_defaults() {
 499                 let offer = OfferBuilder::new("foo".into(), recipient_pubkey())
 500                         .amount_msats(1000)
 501                         .build().unwrap();
 502                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 503                         .build().unwrap().sign(payer_sign).unwrap();
 504
 505                 let (payer_tlv_stream, offer_tlv_stream, invoice_request_tlv_stream, signature_tlv_stream) =
 506                         invoice_request.as_tlv_stream();
 507                 let mut buffer = Vec::new();
 508                 invoice_request.write(&mut buffer).unwrap();
 509
 510                 assert_eq!(invoice_request.bytes, buffer.as_slice());
 511                 assert_eq!(invoice_request.metadata(), &[1; 32]);
 512                 assert_eq!(invoice_request.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
 513                 assert_eq!(invoice_request.amount_msats(), None);
 514                 assert_eq!(invoice_request.features(), &InvoiceRequestFeatures::empty());
 515                 assert_eq!(invoice_request.quantity(), None);
 516                 assert_eq!(invoice_request.payer_id(), payer_pubkey());
 517                 assert_eq!(invoice_request.payer_note(), None);
 518                 assert!(invoice_request.signature().is_some());
 519
 520                 assert_eq!(payer_tlv_stream.metadata, Some(&vec![1; 32]));
 521                 assert_eq!(offer_tlv_stream.chains, None);
 522                 assert_eq!(offer_tlv_stream.metadata, None);
 523                 assert_eq!(offer_tlv_stream.currency, None);
 524                 assert_eq!(offer_tlv_stream.amount, Some(1000));
 525                 assert_eq!(offer_tlv_stream.description, Some(&String::from("foo")));
 526                 assert_eq!(offer_tlv_stream.features, None);
 527                 assert_eq!(offer_tlv_stream.absolute_expiry, None);
 528                 assert_eq!(offer_tlv_stream.paths, None);
 529                 assert_eq!(offer_tlv_stream.issuer, None);
 530                 assert_eq!(offer_tlv_stream.quantity_max, None);
 531                 assert_eq!(offer_tlv_stream.node_id, Some(&recipient_pubkey()));
 532                 assert_eq!(invoice_request_tlv_stream.chain, None);
 533                 assert_eq!(invoice_request_tlv_stream.amount, None);
 534                 assert_eq!(invoice_request_tlv_stream.features, None);
 535                 assert_eq!(invoice_request_tlv_stream.quantity, None);
 536                 assert_eq!(invoice_request_tlv_stream.payer_id, Some(&payer_pubkey()));
 537                 assert_eq!(invoice_request_tlv_stream.payer_note, None);
 538                 assert!(signature_tlv_stream.signature.is_some());
 539
 540                 if let Err(e) = InvoiceRequest::try_from(buffer) {
 541                         panic!("error parsing invoice request: {:?}", e);
 542                 }
 543         }
 544
 545         #[cfg(feature = "std")]
 546         #[test]
 547         fn builds_invoice_request_from_offer_with_expiration() {
 548                 let future_expiry = Duration::from_secs(u64::max_value());
 549                 let past_expiry = Duration::from_secs(0);
 550
 551                 if let Err(e) = OfferBuilder::new("foo".into(), recipient_pubkey())
 552                         .amount_msats(1000)
 553                         .absolute_expiry(future_expiry)
 554                         .build().unwrap()
 555                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 556                         .build()
 557                 {
 558                         panic!("error building invoice_request: {:?}", e);
 559                 }
 560
 561                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 562                         .amount_msats(1000)
 563                         .absolute_expiry(past_expiry)
 564                         .build().unwrap()
 565                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 566                         .build()
 567                 {
 568                         Ok(_) => panic!("expected error"),
 569                         Err(e) => assert_eq!(e, SemanticError::AlreadyExpired),
 570                 }
 571         }
 572
 573         #[test]
 574         fn builds_invoice_request_with_chain() {
 575                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
 576                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
 577
 578                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 579                         .amount_msats(1000)
 580                         .build().unwrap()
 581                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 582                         .chain(Network::Bitcoin).unwrap()
 583                         .build().unwrap()
 584                         .sign(payer_sign).unwrap();
 585                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
 586                 assert_eq!(invoice_request.chain(), mainnet);
 587                 assert_eq!(tlv_stream.chain, None);
 588
 589                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 590                         .amount_msats(1000)
 591                         .chain(Network::Testnet)
 592                         .build().unwrap()
 593                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 594                         .chain(Network::Testnet).unwrap()
 595                         .build().unwrap()
 596                         .sign(payer_sign).unwrap();
 597                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
 598                 assert_eq!(invoice_request.chain(), testnet);
 599                 assert_eq!(tlv_stream.chain, Some(&testnet));
 600
 601                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 602                         .amount_msats(1000)
 603                         .chain(Network::Bitcoin)
 604                         .chain(Network::Testnet)
 605                         .build().unwrap()
 606                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 607                         .chain(Network::Bitcoin).unwrap()
 608                         .build().unwrap()
 609                         .sign(payer_sign).unwrap();
 610                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
 611                 assert_eq!(invoice_request.chain(), mainnet);
 612                 assert_eq!(tlv_stream.chain, None);
 613
 614                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 615                         .amount_msats(1000)
 616                         .chain(Network::Bitcoin)
 617                         .chain(Network::Testnet)
 618                         .build().unwrap()
 619                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 620                         .chain(Network::Bitcoin).unwrap()
 621                         .chain(Network::Testnet).unwrap()
 622                         .build().unwrap()
 623                         .sign(payer_sign).unwrap();
 624                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
 625                 assert_eq!(invoice_request.chain(), testnet);
 626                 assert_eq!(tlv_stream.chain, Some(&testnet));
 627
 628                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 629                         .amount_msats(1000)
 630                         .chain(Network::Testnet)
 631                         .build().unwrap()
 632                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 633                         .chain(Network::Bitcoin)
 634                 {
 635                         Ok(_) => panic!("expected error"),
 636                         Err(e) => assert_eq!(e, SemanticError::UnsupportedChain),
 637                 }
 638
 639                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 640                         .amount_msats(1000)
 641                         .chain(Network::Testnet)
 642                         .build().unwrap()
 643                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 644                         .build()
 645                 {
 646                         Ok(_) => panic!("expected error"),
 647                         Err(e) => assert_eq!(e, SemanticError::UnsupportedChain),
 648                 }
 649         }
 650
 651         #[test]
 652         fn builds_invoice_request_with_amount() {
 653                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 654                         .amount_msats(1000)
 655                         .build().unwrap()
 656                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 657                         .amount_msats(1000).unwrap()
 658                         .build().unwrap()
 659                         .sign(payer_sign).unwrap();
 660                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
 661                 assert_eq!(invoice_request.amount_msats(), Some(1000));
 662                 assert_eq!(tlv_stream.amount, Some(1000));
 663
 664                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 665                         .amount_msats(1000)
 666                         .build().unwrap()
 667                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 668                         .amount_msats(1001).unwrap()
 669                         .amount_msats(1000).unwrap()
 670                         .build().unwrap()
 671                         .sign(payer_sign).unwrap();
 672                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
 673                 assert_eq!(invoice_request.amount_msats(), Some(1000));
 674                 assert_eq!(tlv_stream.amount, Some(1000));
 675
 676                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 677                         .amount_msats(1000)
 678                         .build().unwrap()
 679                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 680                         .amount_msats(1001).unwrap()
 681                         .build().unwrap()
 682                         .sign(payer_sign).unwrap();
 683                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
 684                 assert_eq!(invoice_request.amount_msats(), Some(1001));
 685                 assert_eq!(tlv_stream.amount, Some(1001));
 686
 687                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 688                         .amount_msats(1000)
 689                         .build().unwrap()
 690                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 691                         .amount_msats(999)
 692                 {
 693                         Ok(_) => panic!("expected error"),
 694                         Err(e) => assert_eq!(e, SemanticError::InsufficientAmount),
 695                 }
 696
 697                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 698                         .amount_msats(1000)
 699                         .supported_quantity(Quantity::Unbounded)
 700                         .build().unwrap()
 701                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 702                         .quantity(2).unwrap()
 703                         .amount_msats(1000)
 704                 {
 705                         Ok(_) => panic!("expected error"),
 706                         Err(e) => assert_eq!(e, SemanticError::InsufficientAmount),
 707                 }
 708
 709                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 710                         .amount_msats(1000)
 711                         .build().unwrap()
 712                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 713                         .amount_msats(MAX_VALUE_MSAT + 1)
 714                 {
 715                         Ok(_) => panic!("expected error"),
 716                         Err(e) => assert_eq!(e, SemanticError::InvalidAmount),
 717                 }
 718
 719                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 720                         .amount_msats(1000)
 721                         .supported_quantity(Quantity::Unbounded)
 722                         .build().unwrap()
 723                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 724                         .amount_msats(1000).unwrap()
 725                         .quantity(2).unwrap()
 726                         .build()
 727                 {
 728                         Ok(_) => panic!("expected error"),
 729                         Err(e) => assert_eq!(e, SemanticError::InsufficientAmount),
 730                 }
 731
 732                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 733                         .build().unwrap()
 734                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 735                         .build()
 736                 {
 737                         Ok(_) => panic!("expected error"),
 738                         Err(e) => assert_eq!(e, SemanticError::MissingAmount),
 739                 }
 740         }
 741
 742         #[test]
 743         fn builds_invoice_request_with_features() {
 744                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 745                         .amount_msats(1000)
 746                         .build().unwrap()
 747                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 748                         .features_unchecked(InvoiceRequestFeatures::unknown())
 749                         .build().unwrap()
 750                         .sign(payer_sign).unwrap();
 751                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
 752                 assert_eq!(invoice_request.features(), &InvoiceRequestFeatures::unknown());
 753                 assert_eq!(tlv_stream.features, Some(&InvoiceRequestFeatures::unknown()));
 754
 755                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 756                         .amount_msats(1000)
 757                         .build().unwrap()
 758                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 759                         .features_unchecked(InvoiceRequestFeatures::unknown())
 760                         .features_unchecked(InvoiceRequestFeatures::empty())
 761                         .build().unwrap()
 762                         .sign(payer_sign).unwrap();
 763                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
 764                 assert_eq!(invoice_request.features(), &InvoiceRequestFeatures::empty());
 765                 assert_eq!(tlv_stream.features, None);
 766         }
 767
 768         #[test]
 769         fn builds_invoice_request_with_quantity() {
 770                 let ten = NonZeroU64::new(10).unwrap();
 771
 772                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 773                         .amount_msats(1000)
 774                         .supported_quantity(Quantity::one())
 775                         .build().unwrap()
 776                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 777                         .build().unwrap()
 778                         .sign(payer_sign).unwrap();
 779                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
 780                 assert_eq!(invoice_request.quantity(), None);
 781                 assert_eq!(tlv_stream.quantity, None);
 782
 783                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 784                         .amount_msats(1000)
 785                         .supported_quantity(Quantity::one())
 786                         .build().unwrap()
 787                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 788                         .amount_msats(2_000).unwrap()
 789                         .quantity(2)
 790                 {
 791                         Ok(_) => panic!("expected error"),
 792                         Err(e) => assert_eq!(e, SemanticError::UnexpectedQuantity),
 793                 }
 794
 795                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 796                         .amount_msats(1000)
 797                         .supported_quantity(Quantity::Bounded(ten))
 798                         .build().unwrap()
 799                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 800                         .amount_msats(10_000).unwrap()
 801                         .quantity(10).unwrap()
 802                         .build().unwrap()
 803                         .sign(payer_sign).unwrap();
 804                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
 805                 assert_eq!(invoice_request.amount_msats(), Some(10_000));
 806                 assert_eq!(tlv_stream.amount, Some(10_000));
 807
 808                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 809                         .amount_msats(1000)
 810                         .supported_quantity(Quantity::Bounded(ten))
 811                         .build().unwrap()
 812                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 813                         .amount_msats(11_000).unwrap()
 814                         .quantity(11)
 815                 {
 816                         Ok(_) => panic!("expected error"),
 817                         Err(e) => assert_eq!(e, SemanticError::InvalidQuantity),
 818                 }
 819
 820                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 821                         .amount_msats(1000)
 822                         .supported_quantity(Quantity::Unbounded)
 823                         .build().unwrap()
 824                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 825                         .amount_msats(2_000).unwrap()
 826                         .quantity(2).unwrap()
 827                         .build().unwrap()
 828                         .sign(payer_sign).unwrap();
 829                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
 830                 assert_eq!(invoice_request.amount_msats(), Some(2_000));
 831                 assert_eq!(tlv_stream.amount, Some(2_000));
 832
 833                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 834                         .amount_msats(1000)
 835                         .supported_quantity(Quantity::Unbounded)
 836                         .build().unwrap()
 837                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 838                         .build()
 839                 {
 840                         Ok(_) => panic!("expected error"),
 841                         Err(e) => assert_eq!(e, SemanticError::MissingQuantity),
 842                 }
 843         }
 844
 845         #[test]
 846         fn builds_invoice_request_with_payer_note() {
 847                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 848                         .amount_msats(1000)
 849                         .build().unwrap()
 850                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 851                         .payer_note("bar".into())
 852                         .build().unwrap()
 853                         .sign(payer_sign).unwrap();
 854                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
 855                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("bar")));
 856                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
 857
 858                 let invoice_request = OfferBuilder::new("foo".into(), recipient_pubkey())
 859                         .amount_msats(1000)
 860                         .build().unwrap()
 861                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 862                         .payer_note("bar".into())
 863                         .payer_note("baz".into())
 864                         .build().unwrap()
 865                         .sign(payer_sign).unwrap();
 866                 let (_, _, tlv_stream, _) = invoice_request.as_tlv_stream();
 867                 assert_eq!(invoice_request.payer_note(), Some(PrintableString("baz")));
 868                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
 869         }
 870
 871         #[test]
 872         fn fails_signing_invoice_request() {
 873                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 874                         .amount_msats(1000)
 875                         .build().unwrap()
 876                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 877                         .build().unwrap()
 878                         .sign(|_| Err(()))
 879                 {
 880                         Ok(_) => panic!("expected error"),
 881                         Err(e) => assert_eq!(e, SignError::Signing(())),
 882                 }
 883
 884                 match OfferBuilder::new("foo".into(), recipient_pubkey())
 885                         .amount_msats(1000)
 886                         .build().unwrap()
 887                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
 888                         .build().unwrap()
 889                         .sign(recipient_sign)
 890                 {
 891                         Ok(_) => panic!("expected error"),
 892                         Err(e) => assert_eq!(e, SignError::Verification(secp256k1::Error::InvalidSignature)),
 893                 }
 894         }
 895
 896         #[test]
 897         fn fails_parsing_invoice_request_with_extra_tlv_records() {
 898                 let secp_ctx = Secp256k1::new();
 899                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
 900                 let invoice_request = OfferBuilder::new("foo".into(), keys.public_key())
 901                         .amount_msats(1000)
 902                         .build().unwrap()
 903                         .request_invoice(vec![1; 32], keys.public_key()).unwrap()
 904                         .build().unwrap()
 905                         .sign::<_, Infallible>(|digest| Ok(secp_ctx.sign_schnorr_no_aux_rand(digest, &keys)))
 906                         .unwrap();
 907
 908                 let mut encoded_invoice_request = Vec::new();
 909                 invoice_request.write(&mut encoded_invoice_request).unwrap();
 910                 BigSize(1002).write(&mut encoded_invoice_request).unwrap();
 911                 BigSize(32).write(&mut encoded_invoice_request).unwrap();
 912                 [42u8; 32].write(&mut encoded_invoice_request).unwrap();
 913
 914                 match InvoiceRequest::try_from(encoded_invoice_request) {
 915                         Ok(_) => panic!("expected error"),
 916                         Err(e) => assert_eq!(e, ParseError::Decode(DecodeError::InvalidValue)),
 917                 }
 918         }
 919 }