_ Git - rust-lightning/blob - lightning/src/offers/refund.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 refunds.
  11 //!
  12 //! A [`Refund`] is an "offer for money" and is typically constructed by a merchant and presented
  13 //! directly to the customer. The recipient responds with an `Invoice` to be paid.
  14 //!
  15 //! This is an [`InvoiceRequest`] produced *not* in response to an [`Offer`].
  16 //!
  17 //! [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
  18 //! [`Offer`]: crate::offers::offer::Offer
  19 //!
  20 //! ```ignore
  21 //! extern crate bitcoin;
  22 //! extern crate core;
  23 //! extern crate lightning;
  24 //!
  25 //! use core::convert::TryFrom;
  26 //! use core::time::Duration;
  27 //!
  28 //! use bitcoin::network::constants::Network;
  29 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
  30 //! use lightning::offers::parse::ParseError;
  31 //! use lightning::offers::refund::{Refund, RefundBuilder};
  32 //! use lightning::util::ser::{Readable, Writeable};
  33 //!
  34 //! # use lightning::onion_message::BlindedPath;
  35 //! # #[cfg(feature = "std")]
  36 //! # use std::time::SystemTime;
  37 //! #
  38 //! # fn create_blinded_path() -> BlindedPath { unimplemented!() }
  39 //! # fn create_another_blinded_path() -> BlindedPath { unimplemented!() }
  40 //! #
  41 //! # #[cfg(feature = "std")]
  42 //! # fn build() -> Result<(), ParseError> {
  43 //! let secp_ctx = Secp256k1::new();
  44 //! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
  45 //! let pubkey = PublicKey::from(keys);
  46 //!
  47 //! let expiration = SystemTime::now() + Duration::from_secs(24 * 60 * 60);
  48 //! let refund = RefundBuilder::new("coffee, large".to_string(), vec![1; 32], pubkey, 20_000)?
  49 //!     .absolute_expiry(expiration.duration_since(SystemTime::UNIX_EPOCH).unwrap())
  50 //!     .issuer("Foo Bar".to_string())
  51 //!     .path(create_blinded_path())
  52 //!     .path(create_another_blinded_path())
  53 //!     .chain(Network::Bitcoin)
  54 //!     .payer_note("refund for order #12345".to_string())
  55 //!     .build()?;
  56 //!
  57 //! // Encode as a bech32 string for use in a QR code.
  58 //! let encoded_refund = refund.to_string();
  59 //!
  60 //! // Parse from a bech32 string after scanning from a QR code.
  61 //! let refund = encoded_refund.parse::<Refund>()?;
  62 //!
  63 //! // Encode refund as raw bytes.
  64 //! let mut bytes = Vec::new();
  65 //! refund.write(&mut bytes).unwrap();
  66 //!
  67 //! // Decode raw bytes into an refund.
  68 //! let refund = Refund::try_from(bytes)?;
  69 //! # Ok(())
  70 //! # }
  71 //! ```
  72
  73 use bitcoin::blockdata::constants::ChainHash;
  74 use bitcoin::network::constants::Network;
  75 use bitcoin::secp256k1::PublicKey;
  76 use core::convert::TryFrom;
  77 use core::str::FromStr;
  78 use core::time::Duration;
  79 use crate::io;
  80 use crate::ln::features::InvoiceRequestFeatures;
  81 use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
  82 use crate::offers::invoice_request::{InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef};
  83 use crate::offers::offer::{OfferTlvStream, OfferTlvStreamRef};
  84 use crate::offers::parse::{Bech32Encode, ParseError, ParsedMessage, SemanticError};
  85 use crate::offers::payer::{PayerContents, PayerTlvStream, PayerTlvStreamRef};
  86 use crate::onion_message::BlindedPath;
  87 use crate::util::ser::{SeekReadable, WithoutLength, Writeable, Writer};
  88 use crate::util::string::PrintableString;
  89
  90 use crate::prelude::*;
  91
  92 #[cfg(feature = "std")]
  93 use std::time::SystemTime;
  94
  95 /// Builds a [`Refund`] for the "offer for money" flow.
  96 ///
  97 /// See [module-level documentation] for usage.
  98 ///
  99 /// [module-level documentation]: self
 100 pub struct RefundBuilder {
 101         refund: RefundContents,
 102 }
 103
 104 impl RefundBuilder {
 105         /// Creates a new builder for a refund using the [`Refund::payer_id`] for the public node id to
 106         /// send to if no [`Refund::paths`] are set. Otherwise, it may be a transient pubkey.
 107         ///
 108         /// Additionally, sets the required [`Refund::description`], [`Refund::metadata`], and
 109         /// [`Refund::amount_msats`].
 110         pub fn new(
 111                 description: String, metadata: Vec<u8>, payer_id: PublicKey, amount_msats: u64
 112         ) -> Result<Self, SemanticError> {
 113                 if amount_msats > MAX_VALUE_MSAT {
 114                         return Err(SemanticError::InvalidAmount);
 115                 }
 116
 117                 let refund = RefundContents {
 118                         payer: PayerContents(metadata), metadata: None, description, absolute_expiry: None,
 119                         issuer: None, paths: None, chain: None, amount_msats,
 120                         features: InvoiceRequestFeatures::empty(), payer_id, payer_note: None,
 121                 };
 122
 123                 Ok(RefundBuilder { refund })
 124         }
 125
 126         /// Sets the [`Refund::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
 127         /// already passed is valid and can be checked for using [`Refund::is_expired`].
 128         ///
 129         /// Successive calls to this method will override the previous setting.
 130         pub fn absolute_expiry(mut self, absolute_expiry: Duration) -> Self {
 131                 self.refund.absolute_expiry = Some(absolute_expiry);
 132                 self
 133         }
 134
 135         /// Sets the [`Refund::issuer`].
 136         ///
 137         /// Successive calls to this method will override the previous setting.
 138         pub fn issuer(mut self, issuer: String) -> Self {
 139                 self.refund.issuer = Some(issuer);
 140                 self
 141         }
 142
 143         /// Adds a blinded path to [`Refund::paths`]. Must include at least one path if only connected
 144         /// by private channels or if [`Refund::payer_id`] is not a public node id.
 145         ///
 146         /// Successive calls to this method will add another blinded path. Caller is responsible for not
 147         /// adding duplicate paths.
 148         pub fn path(mut self, path: BlindedPath) -> Self {
 149                 self.refund.paths.get_or_insert_with(Vec::new).push(path);
 150                 self
 151         }
 152
 153         /// Sets the [`Refund::chain`] of the given [`Network`] for paying an invoice. If not
 154         /// called, [`Network::Bitcoin`] is assumed.
 155         ///
 156         /// Successive calls to this method will override the previous setting.
 157         pub fn chain(mut self, network: Network) -> Self {
 158                 self.refund.chain = Some(ChainHash::using_genesis_block(network));
 159                 self
 160         }
 161
 162         /// Sets the [`Refund::payer_note`].
 163         ///
 164         /// Successive calls to this method will override the previous setting.
 165         pub fn payer_note(mut self, payer_note: String) -> Self {
 166                 self.refund.payer_note = Some(payer_note);
 167                 self
 168         }
 169
 170         /// Builds a [`Refund`] after checking for valid semantics.
 171         pub fn build(mut self) -> Result<Refund, SemanticError> {
 172                 if self.refund.chain() == self.refund.implied_chain() {
 173                         self.refund.chain = None;
 174                 }
 175
 176                 let mut bytes = Vec::new();
 177                 self.refund.write(&mut bytes).unwrap();
 178
 179                 Ok(Refund {
 180                         bytes,
 181                         contents: self.refund,
 182                 })
 183         }
 184 }
 185
 186 #[cfg(test)]
 187 impl RefundBuilder {
 188         fn features_unchecked(mut self, features: InvoiceRequestFeatures) -> Self {
 189                 self.refund.features = features;
 190                 self
 191         }
 192 }
 193
 194 /// A `Refund` is a request to send an `Invoice` without a preceding [`Offer`].
 195 ///
 196 /// Typically, after an invoice is paid, the recipient may publish a refund allowing the sender to
 197 /// recoup their funds. A refund may be used more generally as an "offer for money", such as with a
 198 /// bitcoin ATM.
 199 ///
 200 /// [`Offer`]: crate::offers::offer::Offer
 201 #[derive(Clone, Debug)]
 202 pub struct Refund {
 203         bytes: Vec<u8>,
 204         contents: RefundContents,
 205 }
 206
 207 /// The contents of a [`Refund`], which may be shared with an `Invoice`.
 208 #[derive(Clone, Debug)]
 209 struct RefundContents {
 210         payer: PayerContents,
 211         // offer fields
 212         metadata: Option<Vec<u8>>,
 213         description: String,
 214         absolute_expiry: Option<Duration>,
 215         issuer: Option<String>,
 216         paths: Option<Vec<BlindedPath>>,
 217         // invoice_request fields
 218         chain: Option<ChainHash>,
 219         amount_msats: u64,
 220         features: InvoiceRequestFeatures,
 221         payer_id: PublicKey,
 222         payer_note: Option<String>,
 223 }
 224
 225 impl Refund {
 226         /// A complete description of the purpose of the refund. Intended to be displayed to the user
 227         /// but with the caveat that it has not been verified in any way.
 228         pub fn description(&self) -> PrintableString {
 229                 PrintableString(&self.contents.description)
 230         }
 231
 232         /// Duration since the Unix epoch when an invoice should no longer be sent.
 233         ///
 234         /// If `None`, the refund does not expire.
 235         pub fn absolute_expiry(&self) -> Option<Duration> {
 236                 self.contents.absolute_expiry
 237         }
 238
 239         /// Whether the refund has expired.
 240         #[cfg(feature = "std")]
 241         pub fn is_expired(&self) -> bool {
 242                 match self.absolute_expiry() {
 243                         Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() {
 244                                 Ok(elapsed) => elapsed > seconds_from_epoch,
 245                                 Err(_) => false,
 246                         },
 247                         None => false,
 248                 }
 249         }
 250
 251         /// The issuer of the refund, possibly beginning with `user@domain` or `domain`. Intended to be
 252         /// displayed to the user but with the caveat that it has not been verified in any way.
 253         pub fn issuer(&self) -> Option<PrintableString> {
 254                 self.contents.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 255         }
 256
 257         /// Paths to the sender originating from publicly reachable nodes. Blinded paths provide sender
 258         /// privacy by obfuscating its node id.
 259         pub fn paths(&self) -> &[BlindedPath] {
 260                 self.contents.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 261         }
 262
 263         /// An unpredictable series of bytes, typically containing information about the derivation of
 264         /// [`payer_id`].
 265         ///
 266         /// [`payer_id`]: Self::payer_id
 267         pub fn metadata(&self) -> &[u8] {
 268                 &self.contents.payer.0
 269         }
 270
 271         /// A chain that the refund is valid for.
 272         pub fn chain(&self) -> ChainHash {
 273                 self.contents.chain.unwrap_or_else(|| self.contents.implied_chain())
 274         }
 275
 276         /// The amount to refund in msats (i.e., the minimum lightning-payable unit for [`chain`]).
 277         ///
 278         /// [`chain`]: Self::chain
 279         pub fn amount_msats(&self) -> u64 {
 280                 self.contents.amount_msats
 281         }
 282
 283         /// Features pertaining to requesting an invoice.
 284         pub fn features(&self) -> &InvoiceRequestFeatures {
 285                 &self.contents.features
 286         }
 287
 288         /// A public node id to send to in the case where there are no [`paths`]. Otherwise, a possibly
 289         /// transient pubkey.
 290         ///
 291         /// [`paths`]: Self::paths
 292         pub fn payer_id(&self) -> PublicKey {
 293                 self.contents.payer_id
 294         }
 295
 296         /// Payer provided note to include in the invoice.
 297         pub fn payer_note(&self) -> Option<PrintableString> {
 298                 self.contents.payer_note.as_ref().map(|payer_note| PrintableString(payer_note.as_str()))
 299         }
 300
 301         #[cfg(test)]
 302         fn as_tlv_stream(&self) -> RefundTlvStreamRef {
 303                 self.contents.as_tlv_stream()
 304         }
 305 }
 306
 307 impl AsRef<[u8]> for Refund {
 308         fn as_ref(&self) -> &[u8] {
 309                 &self.bytes
 310         }
 311 }
 312
 313 impl RefundContents {
 314         fn chain(&self) -> ChainHash {
 315                 self.chain.unwrap_or_else(|| self.implied_chain())
 316         }
 317
 318         pub fn implied_chain(&self) -> ChainHash {
 319                 ChainHash::using_genesis_block(Network::Bitcoin)
 320         }
 321
 322         pub(super) fn as_tlv_stream(&self) -> RefundTlvStreamRef {
 323                 let payer = PayerTlvStreamRef {
 324                         metadata: Some(&self.payer.0),
 325                 };
 326
 327                 let offer = OfferTlvStreamRef {
 328                         chains: None,
 329                         metadata: self.metadata.as_ref(),
 330                         currency: None,
 331                         amount: None,
 332                         description: Some(&self.description),
 333                         features: None,
 334                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 335                         paths: self.paths.as_ref(),
 336                         issuer: self.issuer.as_ref(),
 337                         quantity_max: None,
 338                         node_id: None,
 339                 };
 340
 341                 let features = {
 342                         if self.features == InvoiceRequestFeatures::empty() { None }
 343                         else { Some(&self.features) }
 344                 };
 345
 346                 let invoice_request = InvoiceRequestTlvStreamRef {
 347                         chain: self.chain.as_ref(),
 348                         amount: Some(self.amount_msats),
 349                         features,
 350                         quantity: None,
 351                         payer_id: Some(&self.payer_id),
 352                         payer_note: self.payer_note.as_ref(),
 353                 };
 354
 355                 (payer, offer, invoice_request)
 356         }
 357 }
 358
 359 impl Writeable for Refund {
 360         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 361                 WithoutLength(&self.bytes).write(writer)
 362         }
 363 }
 364
 365 impl Writeable for RefundContents {
 366         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 367                 self.as_tlv_stream().write(writer)
 368         }
 369 }
 370
 371 type RefundTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
 372
 373 type RefundTlvStreamRef<'a> = (
 374         PayerTlvStreamRef<'a>,
 375         OfferTlvStreamRef<'a>,
 376         InvoiceRequestTlvStreamRef<'a>,
 377 );
 378
 379 impl SeekReadable for RefundTlvStream {
 380         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 381                 let payer = SeekReadable::read(r)?;
 382                 let offer = SeekReadable::read(r)?;
 383                 let invoice_request = SeekReadable::read(r)?;
 384
 385                 Ok((payer, offer, invoice_request))
 386         }
 387 }
 388
 389 impl Bech32Encode for Refund {
 390         const BECH32_HRP: &'static str = "lnr";
 391 }
 392
 393 impl FromStr for Refund {
 394         type Err = ParseError;
 395
 396         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 397                 Refund::from_bech32_str(s)
 398         }
 399 }
 400
 401 impl TryFrom<Vec<u8>> for Refund {
 402         type Error = ParseError;
 403
 404         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 405                 let refund = ParsedMessage::<RefundTlvStream>::try_from(bytes)?;
 406                 let ParsedMessage { bytes, tlv_stream } = refund;
 407                 let contents = RefundContents::try_from(tlv_stream)?;
 408
 409                 Ok(Refund { bytes, contents })
 410         }
 411 }
 412
 413 impl TryFrom<RefundTlvStream> for RefundContents {
 414         type Error = SemanticError;
 415
 416         fn try_from(tlv_stream: RefundTlvStream) -> Result<Self, Self::Error> {
 417                 let (
 418                         PayerTlvStream { metadata: payer_metadata },
 419                         OfferTlvStream {
 420                                 chains, metadata, currency, amount: offer_amount, description,
 421                                 features: offer_features, absolute_expiry, paths, issuer, quantity_max, node_id,
 422                         },
 423                         InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
 424                 ) = tlv_stream;
 425
 426                 let payer = match payer_metadata {
 427                         None => return Err(SemanticError::MissingPayerMetadata),
 428                         Some(metadata) => PayerContents(metadata),
 429                 };
 430
 431                 if chains.is_some() {
 432                         return Err(SemanticError::UnexpectedChain);
 433                 }
 434
 435                 if currency.is_some() || offer_amount.is_some() {
 436                         return Err(SemanticError::UnexpectedAmount);
 437                 }
 438
 439                 let description = match description {
 440                         None => return Err(SemanticError::MissingDescription),
 441                         Some(description) => description,
 442                 };
 443
 444                 if offer_features.is_some() {
 445                         return Err(SemanticError::UnexpectedFeatures);
 446                 }
 447
 448                 let absolute_expiry = absolute_expiry.map(Duration::from_secs);
 449
 450                 if quantity_max.is_some() {
 451                         return Err(SemanticError::UnexpectedQuantity);
 452                 }
 453
 454                 if node_id.is_some() {
 455                         return Err(SemanticError::UnexpectedSigningPubkey);
 456                 }
 457
 458                 let amount_msats = match amount {
 459                         None => return Err(SemanticError::MissingAmount),
 460                         Some(amount_msats) if amount_msats > MAX_VALUE_MSAT => {
 461                                 return Err(SemanticError::InvalidAmount);
 462                         },
 463                         Some(amount_msats) => amount_msats,
 464                 };
 465
 466                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
 467
 468                 // TODO: Check why this isn't in the spec.
 469                 if quantity.is_some() {
 470                         return Err(SemanticError::UnexpectedQuantity);
 471                 }
 472
 473                 let payer_id = match payer_id {
 474                         None => return Err(SemanticError::MissingPayerId),
 475                         Some(payer_id) => payer_id,
 476                 };
 477
 478                 // TODO: Should metadata be included?
 479                 Ok(RefundContents {
 480                         payer, metadata, description, absolute_expiry, issuer, paths, chain, amount_msats,
 481                         features, payer_id, payer_note,
 482                 })
 483         }
 484 }
 485
 486 impl core::fmt::Display for Refund {
 487         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 488                 self.fmt_bech32_str(f)
 489         }
 490 }
 491
 492 #[cfg(test)]
 493 mod tests {
 494         use super::{Refund, RefundBuilder, RefundTlvStreamRef};
 495
 496         use bitcoin::blockdata::constants::ChainHash;
 497         use bitcoin::network::constants::Network;
 498         use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
 499         use core::convert::TryFrom;
 500         use core::time::Duration;
 501         use crate::ln::features::{InvoiceRequestFeatures, OfferFeatures};
 502         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 503         use crate::offers::invoice_request::InvoiceRequestTlvStreamRef;
 504         use crate::offers::offer::OfferTlvStreamRef;
 505         use crate::offers::parse::{ParseError, SemanticError};
 506         use crate::offers::payer::PayerTlvStreamRef;
 507         use crate::onion_message::{BlindedHop, BlindedPath};
 508         use crate::util::ser::{BigSize, Writeable};
 509         use crate::util::string::PrintableString;
 510
 511         fn payer_pubkey() -> PublicKey {
 512                 let secp_ctx = Secp256k1::new();
 513                 KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()).public_key()
 514         }
 515
 516         fn pubkey(byte: u8) -> PublicKey {
 517                 let secp_ctx = Secp256k1::new();
 518                 PublicKey::from_secret_key(&secp_ctx, &privkey(byte))
 519         }
 520
 521         fn privkey(byte: u8) -> SecretKey {
 522                 SecretKey::from_slice(&[byte; 32]).unwrap()
 523         }
 524
 525         trait ToBytes {
 526                 fn to_bytes(&self) -> Vec<u8>;
 527         }
 528
 529         impl<'a> ToBytes for RefundTlvStreamRef<'a> {
 530                 fn to_bytes(&self) -> Vec<u8> {
 531                         let mut buffer = Vec::new();
 532                         self.write(&mut buffer).unwrap();
 533                         buffer
 534                 }
 535         }
 536
 537         #[test]
 538         fn builds_refund_with_defaults() {
 539                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 540                         .build().unwrap();
 541
 542                 let mut buffer = Vec::new();
 543                 refund.write(&mut buffer).unwrap();
 544
 545                 assert_eq!(refund.bytes, buffer.as_slice());
 546                 assert_eq!(refund.metadata(), &[1; 32]);
 547                 assert_eq!(refund.description(), PrintableString("foo"));
 548                 assert_eq!(refund.absolute_expiry(), None);
 549                 #[cfg(feature = "std")]
 550                 assert!(!refund.is_expired());
 551                 assert_eq!(refund.paths(), &[]);
 552                 assert_eq!(refund.issuer(), None);
 553                 assert_eq!(refund.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
 554                 assert_eq!(refund.amount_msats(), 1000);
 555                 assert_eq!(refund.features(), &InvoiceRequestFeatures::empty());
 556                 assert_eq!(refund.payer_id(), payer_pubkey());
 557                 assert_eq!(refund.payer_note(), None);
 558
 559                 assert_eq!(
 560                         refund.as_tlv_stream(),
 561                         (
 562                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
 563                                 OfferTlvStreamRef {
 564                                         chains: None,
 565                                         metadata: None,
 566                                         currency: None,
 567                                         amount: None,
 568                                         description: Some(&String::from("foo")),
 569                                         features: None,
 570                                         absolute_expiry: None,
 571                                         paths: None,
 572                                         issuer: None,
 573                                         quantity_max: None,
 574                                         node_id: None,
 575                                 },
 576                                 InvoiceRequestTlvStreamRef {
 577                                         chain: None,
 578                                         amount: Some(1000),
 579                                         features: None,
 580                                         quantity: None,
 581                                         payer_id: Some(&payer_pubkey()),
 582                                         payer_note: None,
 583                                 },
 584                         ),
 585                 );
 586
 587                 if let Err(e) = Refund::try_from(buffer) {
 588                         panic!("error parsing refund: {:?}", e);
 589                 }
 590         }
 591
 592         #[test]
 593         fn fails_building_refund_with_invalid_amount() {
 594                 match RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), MAX_VALUE_MSAT + 1) {
 595                         Ok(_) => panic!("expected error"),
 596                         Err(e) => assert_eq!(e, SemanticError::InvalidAmount),
 597                 }
 598         }
 599
 600         #[test]
 601         fn builds_refund_with_absolute_expiry() {
 602                 let future_expiry = Duration::from_secs(u64::max_value());
 603                 let past_expiry = Duration::from_secs(0);
 604
 605                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 606                         .absolute_expiry(future_expiry)
 607                         .build()
 608                         .unwrap();
 609                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 610                 #[cfg(feature = "std")]
 611                 assert!(!refund.is_expired());
 612                 assert_eq!(refund.absolute_expiry(), Some(future_expiry));
 613                 assert_eq!(tlv_stream.absolute_expiry, Some(future_expiry.as_secs()));
 614
 615                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 616                         .absolute_expiry(future_expiry)
 617                         .absolute_expiry(past_expiry)
 618                         .build()
 619                         .unwrap();
 620                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 621                 #[cfg(feature = "std")]
 622                 assert!(refund.is_expired());
 623                 assert_eq!(refund.absolute_expiry(), Some(past_expiry));
 624                 assert_eq!(tlv_stream.absolute_expiry, Some(past_expiry.as_secs()));
 625         }
 626
 627         #[test]
 628         fn builds_refund_with_paths() {
 629                 let paths = vec![
 630                         BlindedPath {
 631                                 introduction_node_id: pubkey(40),
 632                                 blinding_point: pubkey(41),
 633                                 blinded_hops: vec![
 634                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
 635                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
 636                                 ],
 637                         },
 638                         BlindedPath {
 639                                 introduction_node_id: pubkey(40),
 640                                 blinding_point: pubkey(41),
 641                                 blinded_hops: vec![
 642                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
 643                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
 644                                 ],
 645                         },
 646                 ];
 647
 648                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 649                         .path(paths[0].clone())
 650                         .path(paths[1].clone())
 651                         .build()
 652                         .unwrap();
 653                 let (_, offer_tlv_stream, invoice_request_tlv_stream) = refund.as_tlv_stream();
 654                 assert_eq!(refund.paths(), paths.as_slice());
 655                 assert_eq!(refund.payer_id(), pubkey(42));
 656                 assert_ne!(pubkey(42), pubkey(44));
 657                 assert_eq!(offer_tlv_stream.paths, Some(&paths));
 658                 assert_eq!(invoice_request_tlv_stream.payer_id, Some(&pubkey(42)));
 659         }
 660
 661         #[test]
 662         fn builds_refund_with_issuer() {
 663                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 664                         .issuer("bar".into())
 665                         .build()
 666                         .unwrap();
 667                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 668                 assert_eq!(refund.issuer(), Some(PrintableString("bar")));
 669                 assert_eq!(tlv_stream.issuer, Some(&String::from("bar")));
 670
 671                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 672                         .issuer("bar".into())
 673                         .issuer("baz".into())
 674                         .build()
 675                         .unwrap();
 676                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 677                 assert_eq!(refund.issuer(), Some(PrintableString("baz")));
 678                 assert_eq!(tlv_stream.issuer, Some(&String::from("baz")));
 679         }
 680
 681         #[test]
 682         fn builds_refund_with_chain() {
 683                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
 684                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
 685
 686                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 687                         .chain(Network::Bitcoin)
 688                         .build().unwrap();
 689                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 690                 assert_eq!(refund.chain(), mainnet);
 691                 assert_eq!(tlv_stream.chain, None);
 692
 693                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 694                         .chain(Network::Testnet)
 695                         .build().unwrap();
 696                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 697                 assert_eq!(refund.chain(), testnet);
 698                 assert_eq!(tlv_stream.chain, Some(&testnet));
 699
 700                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 701                         .chain(Network::Regtest)
 702                         .chain(Network::Testnet)
 703                         .build().unwrap();
 704                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 705                 assert_eq!(refund.chain(), testnet);
 706                 assert_eq!(tlv_stream.chain, Some(&testnet));
 707         }
 708
 709         #[test]
 710         fn builds_refund_with_payer_note() {
 711                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 712                         .payer_note("bar".into())
 713                         .build().unwrap();
 714                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 715                 assert_eq!(refund.payer_note(), Some(PrintableString("bar")));
 716                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
 717
 718                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 719                         .payer_note("bar".into())
 720                         .payer_note("baz".into())
 721                         .build().unwrap();
 722                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 723                 assert_eq!(refund.payer_note(), Some(PrintableString("baz")));
 724                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
 725         }
 726
 727         #[test]
 728         fn parses_refund_with_metadata() {
 729                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 730                         .build().unwrap();
 731                 if let Err(e) = refund.to_string().parse::<Refund>() {
 732                         panic!("error parsing refund: {:?}", e);
 733                 }
 734
 735                 let mut tlv_stream = refund.as_tlv_stream();
 736                 tlv_stream.0.metadata = None;
 737
 738                 match Refund::try_from(tlv_stream.to_bytes()) {
 739                         Ok(_) => panic!("expected error"),
 740                         Err(e) => {
 741                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPayerMetadata));
 742                         },
 743                 }
 744         }
 745
 746         #[test]
 747         fn parses_refund_with_description() {
 748                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 749                         .build().unwrap();
 750                 if let Err(e) = refund.to_string().parse::<Refund>() {
 751                         panic!("error parsing refund: {:?}", e);
 752                 }
 753
 754                 let mut tlv_stream = refund.as_tlv_stream();
 755                 tlv_stream.1.description = None;
 756
 757                 match Refund::try_from(tlv_stream.to_bytes()) {
 758                         Ok(_) => panic!("expected error"),
 759                         Err(e) => {
 760                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingDescription));
 761                         },
 762                 }
 763         }
 764
 765         #[test]
 766         fn parses_refund_with_amount() {
 767                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 768                         .build().unwrap();
 769                 if let Err(e) = refund.to_string().parse::<Refund>() {
 770                         panic!("error parsing refund: {:?}", e);
 771                 }
 772
 773                 let mut tlv_stream = refund.as_tlv_stream();
 774                 tlv_stream.2.amount = None;
 775
 776                 match Refund::try_from(tlv_stream.to_bytes()) {
 777                         Ok(_) => panic!("expected error"),
 778                         Err(e) => {
 779                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingAmount));
 780                         },
 781                 }
 782
 783                 let mut tlv_stream = refund.as_tlv_stream();
 784                 tlv_stream.2.amount = Some(MAX_VALUE_MSAT + 1);
 785
 786                 match Refund::try_from(tlv_stream.to_bytes()) {
 787                         Ok(_) => panic!("expected error"),
 788                         Err(e) => {
 789                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::InvalidAmount));
 790                         },
 791                 }
 792         }
 793
 794         #[test]
 795         fn parses_refund_with_payer_id() {
 796                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 797                         .build().unwrap();
 798                 if let Err(e) = refund.to_string().parse::<Refund>() {
 799                         panic!("error parsing refund: {:?}", e);
 800                 }
 801
 802                 let mut tlv_stream = refund.as_tlv_stream();
 803                 tlv_stream.2.payer_id = None;
 804
 805                 match Refund::try_from(tlv_stream.to_bytes()) {
 806                         Ok(_) => panic!("expected error"),
 807                         Err(e) => {
 808                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPayerId));
 809                         },
 810                 }
 811         }
 812
 813         #[test]
 814         fn parses_refund_with_optional_fields() {
 815                 let past_expiry = Duration::from_secs(0);
 816                 let paths = vec![
 817                         BlindedPath {
 818                                 introduction_node_id: pubkey(40),
 819                                 blinding_point: pubkey(41),
 820                                 blinded_hops: vec![
 821                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
 822                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
 823                                 ],
 824                         },
 825                         BlindedPath {
 826                                 introduction_node_id: pubkey(40),
 827                                 blinding_point: pubkey(41),
 828                                 blinded_hops: vec![
 829                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
 830                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
 831                                 ],
 832                         },
 833                 ];
 834
 835                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 836                         .absolute_expiry(past_expiry)
 837                         .issuer("bar".into())
 838                         .path(paths[0].clone())
 839                         .path(paths[1].clone())
 840                         .chain(Network::Testnet)
 841                         .features_unchecked(InvoiceRequestFeatures::unknown())
 842                         .payer_note("baz".into())
 843                         .build()
 844                         .unwrap();
 845                 match refund.to_string().parse::<Refund>() {
 846                         Ok(refund) => {
 847                                 assert_eq!(refund.absolute_expiry(), Some(past_expiry));
 848                                 #[cfg(feature = "std")]
 849                                 assert!(refund.is_expired());
 850                                 assert_eq!(refund.paths(), &paths[..]);
 851                                 assert_eq!(refund.issuer(), Some(PrintableString("bar")));
 852                                 assert_eq!(refund.chain(), ChainHash::using_genesis_block(Network::Testnet));
 853                                 assert_eq!(refund.features(), &InvoiceRequestFeatures::unknown());
 854                                 assert_eq!(refund.payer_note(), Some(PrintableString("baz")));
 855                         },
 856                         Err(e) => panic!("error parsing refund: {:?}", e),
 857                 }
 858         }
 859
 860         #[test]
 861         fn fails_parsing_refund_with_unexpected_fields() {
 862                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 863                         .build().unwrap();
 864                 if let Err(e) = refund.to_string().parse::<Refund>() {
 865                         panic!("error parsing refund: {:?}", e);
 866                 }
 867
 868                 let chains = vec![ChainHash::using_genesis_block(Network::Testnet)];
 869                 let mut tlv_stream = refund.as_tlv_stream();
 870                 tlv_stream.1.chains = Some(&chains);
 871
 872                 match Refund::try_from(tlv_stream.to_bytes()) {
 873                         Ok(_) => panic!("expected error"),
 874                         Err(e) => {
 875                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedChain));
 876                         },
 877                 }
 878
 879                 let mut tlv_stream = refund.as_tlv_stream();
 880                 tlv_stream.1.currency = Some(&b"USD");
 881                 tlv_stream.1.amount = Some(1000);
 882
 883                 match Refund::try_from(tlv_stream.to_bytes()) {
 884                         Ok(_) => panic!("expected error"),
 885                         Err(e) => {
 886                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedAmount));
 887                         },
 888                 }
 889
 890                 let features = OfferFeatures::unknown();
 891                 let mut tlv_stream = refund.as_tlv_stream();
 892                 tlv_stream.1.features = Some(&features);
 893
 894                 match Refund::try_from(tlv_stream.to_bytes()) {
 895                         Ok(_) => panic!("expected error"),
 896                         Err(e) => {
 897                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedFeatures));
 898                         },
 899                 }
 900
 901                 let mut tlv_stream = refund.as_tlv_stream();
 902                 tlv_stream.1.quantity_max = Some(10);
 903
 904                 match Refund::try_from(tlv_stream.to_bytes()) {
 905                         Ok(_) => panic!("expected error"),
 906                         Err(e) => {
 907                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedQuantity));
 908                         },
 909                 }
 910
 911                 let node_id = payer_pubkey();
 912                 let mut tlv_stream = refund.as_tlv_stream();
 913                 tlv_stream.1.node_id = Some(&node_id);
 914
 915                 match Refund::try_from(tlv_stream.to_bytes()) {
 916                         Ok(_) => panic!("expected error"),
 917                         Err(e) => {
 918                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedSigningPubkey));
 919                         },
 920                 }
 921
 922                 let mut tlv_stream = refund.as_tlv_stream();
 923                 tlv_stream.2.quantity = Some(10);
 924
 925                 match Refund::try_from(tlv_stream.to_bytes()) {
 926                         Ok(_) => panic!("expected error"),
 927                         Err(e) => {
 928                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedQuantity));
 929                         },
 930                 }
 931         }
 932
 933         #[test]
 934         fn fails_parsing_refund_with_extra_tlv_records() {
 935                 let secp_ctx = Secp256k1::new();
 936                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
 937                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], keys.public_key(), 1000).unwrap()
 938                         .build().unwrap();
 939
 940                 let mut encoded_refund = Vec::new();
 941                 refund.write(&mut encoded_refund).unwrap();
 942                 BigSize(1002).write(&mut encoded_refund).unwrap();
 943                 BigSize(32).write(&mut encoded_refund).unwrap();
 944                 [42u8; 32].write(&mut encoded_refund).unwrap();
 945
 946                 match Refund::try_from(encoded_refund) {
 947                         Ok(_) => panic!("expected error"),
 948                         Err(e) => assert_eq!(e, ParseError::Decode(DecodeError::InvalidValue)),
 949                 }
 950         }
 951 }