git.bitcoin.ninja 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 //! [`Invoice`]: crate::offers::invoice::Invoice
  18 //! [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
  19 //! [`Offer`]: crate::offers::offer::Offer
  20 //!
  21 //! ```ignore
  22 //! extern crate bitcoin;
  23 //! extern crate core;
  24 //! extern crate lightning;
  25 //!
  26 //! use core::convert::TryFrom;
  27 //! use core::time::Duration;
  28 //!
  29 //! use bitcoin::network::constants::Network;
  30 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
  31 //! use lightning::offers::parse::ParseError;
  32 //! use lightning::offers::refund::{Refund, RefundBuilder};
  33 //! use lightning::util::ser::{Readable, Writeable};
  34 //!
  35 //! # use lightning::onion_message::BlindedPath;
  36 //! # #[cfg(feature = "std")]
  37 //! # use std::time::SystemTime;
  38 //! #
  39 //! # fn create_blinded_path() -> BlindedPath { unimplemented!() }
  40 //! # fn create_another_blinded_path() -> BlindedPath { unimplemented!() }
  41 //! #
  42 //! # #[cfg(feature = "std")]
  43 //! # fn build() -> Result<(), ParseError> {
  44 //! let secp_ctx = Secp256k1::new();
  45 //! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
  46 //! let pubkey = PublicKey::from(keys);
  47 //!
  48 //! let expiration = SystemTime::now() + Duration::from_secs(24 * 60 * 60);
  49 //! let refund = RefundBuilder::new("coffee, large".to_string(), vec![1; 32], pubkey, 20_000)?
  50 //!     .absolute_expiry(expiration.duration_since(SystemTime::UNIX_EPOCH).unwrap())
  51 //!     .issuer("Foo Bar".to_string())
  52 //!     .path(create_blinded_path())
  53 //!     .path(create_another_blinded_path())
  54 //!     .chain(Network::Bitcoin)
  55 //!     .payer_note("refund for order #12345".to_string())
  56 //!     .build()?;
  57 //!
  58 //! // Encode as a bech32 string for use in a QR code.
  59 //! let encoded_refund = refund.to_string();
  60 //!
  61 //! // Parse from a bech32 string after scanning from a QR code.
  62 //! let refund = encoded_refund.parse::<Refund>()?;
  63 //!
  64 //! // Encode refund as raw bytes.
  65 //! let mut bytes = Vec::new();
  66 //! refund.write(&mut bytes).unwrap();
  67 //!
  68 //! // Decode raw bytes into an refund.
  69 //! let refund = Refund::try_from(bytes)?;
  70 //! # Ok(())
  71 //! # }
  72 //! ```
  73
  74 use bitcoin::blockdata::constants::ChainHash;
  75 use bitcoin::network::constants::Network;
  76 use bitcoin::secp256k1::PublicKey;
  77 use core::convert::TryFrom;
  78 use core::str::FromStr;
  79 use core::time::Duration;
  80 use crate::io;
  81 use crate::ln::features::InvoiceRequestFeatures;
  82 use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
  83 use crate::offers::invoice_request::{InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef};
  84 use crate::offers::offer::{OfferTlvStream, OfferTlvStreamRef};
  85 use crate::offers::parse::{Bech32Encode, ParseError, ParsedMessage, SemanticError};
  86 use crate::offers::payer::{PayerContents, PayerTlvStream, PayerTlvStreamRef};
  87 use crate::onion_message::BlindedPath;
  88 use crate::util::ser::{SeekReadable, WithoutLength, Writeable, Writer};
  89 use crate::util::string::PrintableString;
  90
  91 use crate::prelude::*;
  92
  93 #[cfg(feature = "std")]
  94 use std::time::SystemTime;
  95
  96 /// Builds a [`Refund`] for the "offer for money" flow.
  97 ///
  98 /// See [module-level documentation] for usage.
  99 ///
 100 /// [module-level documentation]: self
 101 pub struct RefundBuilder {
 102         refund: RefundContents,
 103 }
 104
 105 impl RefundBuilder {
 106         /// Creates a new builder for a refund using the [`Refund::payer_id`] for the public node id to
 107         /// send to if no [`Refund::paths`] are set. Otherwise, it may be a transient pubkey.
 108         ///
 109         /// Additionally, sets the required [`Refund::description`], [`Refund::metadata`], and
 110         /// [`Refund::amount_msats`].
 111         pub fn new(
 112                 description: String, metadata: Vec<u8>, payer_id: PublicKey, amount_msats: u64
 113         ) -> Result<Self, SemanticError> {
 114                 if amount_msats > MAX_VALUE_MSAT {
 115                         return Err(SemanticError::InvalidAmount);
 116                 }
 117
 118                 let refund = RefundContents {
 119                         payer: PayerContents(metadata), metadata: None, description, absolute_expiry: None,
 120                         issuer: None, paths: None, chain: None, amount_msats,
 121                         features: InvoiceRequestFeatures::empty(), payer_id, payer_note: None,
 122                 };
 123
 124                 Ok(RefundBuilder { refund })
 125         }
 126
 127         /// Sets the [`Refund::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
 128         /// already passed is valid and can be checked for using [`Refund::is_expired`].
 129         ///
 130         /// Successive calls to this method will override the previous setting.
 131         pub fn absolute_expiry(mut self, absolute_expiry: Duration) -> Self {
 132                 self.refund.absolute_expiry = Some(absolute_expiry);
 133                 self
 134         }
 135
 136         /// Sets the [`Refund::issuer`].
 137         ///
 138         /// Successive calls to this method will override the previous setting.
 139         pub fn issuer(mut self, issuer: String) -> Self {
 140                 self.refund.issuer = Some(issuer);
 141                 self
 142         }
 143
 144         /// Adds a blinded path to [`Refund::paths`]. Must include at least one path if only connected
 145         /// by private channels or if [`Refund::payer_id`] is not a public node id.
 146         ///
 147         /// Successive calls to this method will add another blinded path. Caller is responsible for not
 148         /// adding duplicate paths.
 149         pub fn path(mut self, path: BlindedPath) -> Self {
 150                 self.refund.paths.get_or_insert_with(Vec::new).push(path);
 151                 self
 152         }
 153
 154         /// Sets the [`Refund::chain`] of the given [`Network`] for paying an invoice. If not
 155         /// called, [`Network::Bitcoin`] is assumed.
 156         ///
 157         /// Successive calls to this method will override the previous setting.
 158         pub fn chain(mut self, network: Network) -> Self {
 159                 self.refund.chain = Some(ChainHash::using_genesis_block(network));
 160                 self
 161         }
 162
 163         /// Sets the [`Refund::payer_note`].
 164         ///
 165         /// Successive calls to this method will override the previous setting.
 166         pub fn payer_note(mut self, payer_note: String) -> Self {
 167                 self.refund.payer_note = Some(payer_note);
 168                 self
 169         }
 170
 171         /// Builds a [`Refund`] after checking for valid semantics.
 172         pub fn build(mut self) -> Result<Refund, SemanticError> {
 173                 if self.refund.chain() == self.refund.implied_chain() {
 174                         self.refund.chain = None;
 175                 }
 176
 177                 let mut bytes = Vec::new();
 178                 self.refund.write(&mut bytes).unwrap();
 179
 180                 Ok(Refund {
 181                         bytes,
 182                         contents: self.refund,
 183                 })
 184         }
 185 }
 186
 187 #[cfg(test)]
 188 impl RefundBuilder {
 189         fn features_unchecked(mut self, features: InvoiceRequestFeatures) -> Self {
 190                 self.refund.features = features;
 191                 self
 192         }
 193 }
 194
 195 /// A `Refund` is a request to send an [`Invoice`] without a preceding [`Offer`].
 196 ///
 197 /// Typically, after an invoice is paid, the recipient may publish a refund allowing the sender to
 198 /// recoup their funds. A refund may be used more generally as an "offer for money", such as with a
 199 /// bitcoin ATM.
 200 ///
 201 /// [`Invoice`]: crate::offers::invoice::Invoice
 202 /// [`Offer`]: crate::offers::offer::Offer
 203 #[derive(Clone, Debug)]
 204 pub struct Refund {
 205         bytes: Vec<u8>,
 206         contents: RefundContents,
 207 }
 208
 209 /// The contents of a [`Refund`], which may be shared with an [`Invoice`].
 210 ///
 211 /// [`Invoice`]: crate::offers::invoice::Invoice
 212 #[derive(Clone, Debug)]
 213 pub(super) struct RefundContents {
 214         payer: PayerContents,
 215         // offer fields
 216         metadata: Option<Vec<u8>>,
 217         description: String,
 218         absolute_expiry: Option<Duration>,
 219         issuer: Option<String>,
 220         paths: Option<Vec<BlindedPath>>,
 221         // invoice_request fields
 222         chain: Option<ChainHash>,
 223         amount_msats: u64,
 224         features: InvoiceRequestFeatures,
 225         payer_id: PublicKey,
 226         payer_note: Option<String>,
 227 }
 228
 229 impl Refund {
 230         /// A complete description of the purpose of the refund. Intended to be displayed to the user
 231         /// but with the caveat that it has not been verified in any way.
 232         pub fn description(&self) -> PrintableString {
 233                 PrintableString(&self.contents.description)
 234         }
 235
 236         /// Duration since the Unix epoch when an invoice should no longer be sent.
 237         ///
 238         /// If `None`, the refund does not expire.
 239         pub fn absolute_expiry(&self) -> Option<Duration> {
 240                 self.contents.absolute_expiry
 241         }
 242
 243         /// Whether the refund has expired.
 244         #[cfg(feature = "std")]
 245         pub fn is_expired(&self) -> bool {
 246                 match self.absolute_expiry() {
 247                         Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() {
 248                                 Ok(elapsed) => elapsed > seconds_from_epoch,
 249                                 Err(_) => false,
 250                         },
 251                         None => false,
 252                 }
 253         }
 254
 255         /// The issuer of the refund, possibly beginning with `user@domain` or `domain`. Intended to be
 256         /// displayed to the user but with the caveat that it has not been verified in any way.
 257         pub fn issuer(&self) -> Option<PrintableString> {
 258                 self.contents.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 259         }
 260
 261         /// Paths to the sender originating from publicly reachable nodes. Blinded paths provide sender
 262         /// privacy by obfuscating its node id.
 263         pub fn paths(&self) -> &[BlindedPath] {
 264                 self.contents.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 265         }
 266
 267         /// An unpredictable series of bytes, typically containing information about the derivation of
 268         /// [`payer_id`].
 269         ///
 270         /// [`payer_id`]: Self::payer_id
 271         pub fn metadata(&self) -> &[u8] {
 272                 &self.contents.payer.0
 273         }
 274
 275         /// A chain that the refund is valid for.
 276         pub fn chain(&self) -> ChainHash {
 277                 self.contents.chain.unwrap_or_else(|| self.contents.implied_chain())
 278         }
 279
 280         /// The amount to refund in msats (i.e., the minimum lightning-payable unit for [`chain`]).
 281         ///
 282         /// [`chain`]: Self::chain
 283         pub fn amount_msats(&self) -> u64 {
 284                 self.contents.amount_msats
 285         }
 286
 287         /// Features pertaining to requesting an invoice.
 288         pub fn features(&self) -> &InvoiceRequestFeatures {
 289                 &self.contents.features
 290         }
 291
 292         /// A public node id to send to in the case where there are no [`paths`]. Otherwise, a possibly
 293         /// transient pubkey.
 294         ///
 295         /// [`paths`]: Self::paths
 296         pub fn payer_id(&self) -> PublicKey {
 297                 self.contents.payer_id
 298         }
 299
 300         /// Payer provided note to include in the invoice.
 301         pub fn payer_note(&self) -> Option<PrintableString> {
 302                 self.contents.payer_note.as_ref().map(|payer_note| PrintableString(payer_note.as_str()))
 303         }
 304
 305         #[cfg(test)]
 306         fn as_tlv_stream(&self) -> RefundTlvStreamRef {
 307                 self.contents.as_tlv_stream()
 308         }
 309 }
 310
 311 impl AsRef<[u8]> for Refund {
 312         fn as_ref(&self) -> &[u8] {
 313                 &self.bytes
 314         }
 315 }
 316
 317 impl RefundContents {
 318         pub(super) fn chain(&self) -> ChainHash {
 319                 self.chain.unwrap_or_else(|| self.implied_chain())
 320         }
 321
 322         pub fn implied_chain(&self) -> ChainHash {
 323                 ChainHash::using_genesis_block(Network::Bitcoin)
 324         }
 325
 326         pub(super) fn as_tlv_stream(&self) -> RefundTlvStreamRef {
 327                 let payer = PayerTlvStreamRef {
 328                         metadata: Some(&self.payer.0),
 329                 };
 330
 331                 let offer = OfferTlvStreamRef {
 332                         chains: None,
 333                         metadata: self.metadata.as_ref(),
 334                         currency: None,
 335                         amount: None,
 336                         description: Some(&self.description),
 337                         features: None,
 338                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 339                         paths: self.paths.as_ref(),
 340                         issuer: self.issuer.as_ref(),
 341                         quantity_max: None,
 342                         node_id: None,
 343                 };
 344
 345                 let features = {
 346                         if self.features == InvoiceRequestFeatures::empty() { None }
 347                         else { Some(&self.features) }
 348                 };
 349
 350                 let invoice_request = InvoiceRequestTlvStreamRef {
 351                         chain: self.chain.as_ref(),
 352                         amount: Some(self.amount_msats),
 353                         features,
 354                         quantity: None,
 355                         payer_id: Some(&self.payer_id),
 356                         payer_note: self.payer_note.as_ref(),
 357                 };
 358
 359                 (payer, offer, invoice_request)
 360         }
 361 }
 362
 363 impl Writeable for Refund {
 364         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 365                 WithoutLength(&self.bytes).write(writer)
 366         }
 367 }
 368
 369 impl Writeable for RefundContents {
 370         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 371                 self.as_tlv_stream().write(writer)
 372         }
 373 }
 374
 375 type RefundTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
 376
 377 type RefundTlvStreamRef<'a> = (
 378         PayerTlvStreamRef<'a>,
 379         OfferTlvStreamRef<'a>,
 380         InvoiceRequestTlvStreamRef<'a>,
 381 );
 382
 383 impl SeekReadable for RefundTlvStream {
 384         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 385                 let payer = SeekReadable::read(r)?;
 386                 let offer = SeekReadable::read(r)?;
 387                 let invoice_request = SeekReadable::read(r)?;
 388
 389                 Ok((payer, offer, invoice_request))
 390         }
 391 }
 392
 393 impl Bech32Encode for Refund {
 394         const BECH32_HRP: &'static str = "lnr";
 395 }
 396
 397 impl FromStr for Refund {
 398         type Err = ParseError;
 399
 400         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 401                 Refund::from_bech32_str(s)
 402         }
 403 }
 404
 405 impl TryFrom<Vec<u8>> for Refund {
 406         type Error = ParseError;
 407
 408         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 409                 let refund = ParsedMessage::<RefundTlvStream>::try_from(bytes)?;
 410                 let ParsedMessage { bytes, tlv_stream } = refund;
 411                 let contents = RefundContents::try_from(tlv_stream)?;
 412
 413                 Ok(Refund { bytes, contents })
 414         }
 415 }
 416
 417 impl TryFrom<RefundTlvStream> for RefundContents {
 418         type Error = SemanticError;
 419
 420         fn try_from(tlv_stream: RefundTlvStream) -> Result<Self, Self::Error> {
 421                 let (
 422                         PayerTlvStream { metadata: payer_metadata },
 423                         OfferTlvStream {
 424                                 chains, metadata, currency, amount: offer_amount, description,
 425                                 features: offer_features, absolute_expiry, paths, issuer, quantity_max, node_id,
 426                         },
 427                         InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
 428                 ) = tlv_stream;
 429
 430                 let payer = match payer_metadata {
 431                         None => return Err(SemanticError::MissingPayerMetadata),
 432                         Some(metadata) => PayerContents(metadata),
 433                 };
 434
 435                 if chains.is_some() {
 436                         return Err(SemanticError::UnexpectedChain);
 437                 }
 438
 439                 if currency.is_some() || offer_amount.is_some() {
 440                         return Err(SemanticError::UnexpectedAmount);
 441                 }
 442
 443                 let description = match description {
 444                         None => return Err(SemanticError::MissingDescription),
 445                         Some(description) => description,
 446                 };
 447
 448                 if offer_features.is_some() {
 449                         return Err(SemanticError::UnexpectedFeatures);
 450                 }
 451
 452                 let absolute_expiry = absolute_expiry.map(Duration::from_secs);
 453
 454                 if quantity_max.is_some() {
 455                         return Err(SemanticError::UnexpectedQuantity);
 456                 }
 457
 458                 if node_id.is_some() {
 459                         return Err(SemanticError::UnexpectedSigningPubkey);
 460                 }
 461
 462                 let amount_msats = match amount {
 463                         None => return Err(SemanticError::MissingAmount),
 464                         Some(amount_msats) if amount_msats > MAX_VALUE_MSAT => {
 465                                 return Err(SemanticError::InvalidAmount);
 466                         },
 467                         Some(amount_msats) => amount_msats,
 468                 };
 469
 470                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
 471
 472                 // TODO: Check why this isn't in the spec.
 473                 if quantity.is_some() {
 474                         return Err(SemanticError::UnexpectedQuantity);
 475                 }
 476
 477                 let payer_id = match payer_id {
 478                         None => return Err(SemanticError::MissingPayerId),
 479                         Some(payer_id) => payer_id,
 480                 };
 481
 482                 // TODO: Should metadata be included?
 483                 Ok(RefundContents {
 484                         payer, metadata, description, absolute_expiry, issuer, paths, chain, amount_msats,
 485                         features, payer_id, payer_note,
 486                 })
 487         }
 488 }
 489
 490 impl core::fmt::Display for Refund {
 491         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 492                 self.fmt_bech32_str(f)
 493         }
 494 }
 495
 496 #[cfg(test)]
 497 mod tests {
 498         use super::{Refund, RefundBuilder, RefundTlvStreamRef};
 499
 500         use bitcoin::blockdata::constants::ChainHash;
 501         use bitcoin::network::constants::Network;
 502         use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
 503         use core::convert::TryFrom;
 504         use core::time::Duration;
 505         use crate::ln::features::{InvoiceRequestFeatures, OfferFeatures};
 506         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 507         use crate::offers::invoice_request::InvoiceRequestTlvStreamRef;
 508         use crate::offers::offer::OfferTlvStreamRef;
 509         use crate::offers::parse::{ParseError, SemanticError};
 510         use crate::offers::payer::PayerTlvStreamRef;
 511         use crate::onion_message::{BlindedHop, BlindedPath};
 512         use crate::util::ser::{BigSize, Writeable};
 513         use crate::util::string::PrintableString;
 514
 515         fn payer_pubkey() -> PublicKey {
 516                 let secp_ctx = Secp256k1::new();
 517                 KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()).public_key()
 518         }
 519
 520         fn pubkey(byte: u8) -> PublicKey {
 521                 let secp_ctx = Secp256k1::new();
 522                 PublicKey::from_secret_key(&secp_ctx, &privkey(byte))
 523         }
 524
 525         fn privkey(byte: u8) -> SecretKey {
 526                 SecretKey::from_slice(&[byte; 32]).unwrap()
 527         }
 528
 529         trait ToBytes {
 530                 fn to_bytes(&self) -> Vec<u8>;
 531         }
 532
 533         impl<'a> ToBytes for RefundTlvStreamRef<'a> {
 534                 fn to_bytes(&self) -> Vec<u8> {
 535                         let mut buffer = Vec::new();
 536                         self.write(&mut buffer).unwrap();
 537                         buffer
 538                 }
 539         }
 540
 541         #[test]
 542         fn builds_refund_with_defaults() {
 543                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 544                         .build().unwrap();
 545
 546                 let mut buffer = Vec::new();
 547                 refund.write(&mut buffer).unwrap();
 548
 549                 assert_eq!(refund.bytes, buffer.as_slice());
 550                 assert_eq!(refund.metadata(), &[1; 32]);
 551                 assert_eq!(refund.description(), PrintableString("foo"));
 552                 assert_eq!(refund.absolute_expiry(), None);
 553                 #[cfg(feature = "std")]
 554                 assert!(!refund.is_expired());
 555                 assert_eq!(refund.paths(), &[]);
 556                 assert_eq!(refund.issuer(), None);
 557                 assert_eq!(refund.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
 558                 assert_eq!(refund.amount_msats(), 1000);
 559                 assert_eq!(refund.features(), &InvoiceRequestFeatures::empty());
 560                 assert_eq!(refund.payer_id(), payer_pubkey());
 561                 assert_eq!(refund.payer_note(), None);
 562
 563                 assert_eq!(
 564                         refund.as_tlv_stream(),
 565                         (
 566                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
 567                                 OfferTlvStreamRef {
 568                                         chains: None,
 569                                         metadata: None,
 570                                         currency: None,
 571                                         amount: None,
 572                                         description: Some(&String::from("foo")),
 573                                         features: None,
 574                                         absolute_expiry: None,
 575                                         paths: None,
 576                                         issuer: None,
 577                                         quantity_max: None,
 578                                         node_id: None,
 579                                 },
 580                                 InvoiceRequestTlvStreamRef {
 581                                         chain: None,
 582                                         amount: Some(1000),
 583                                         features: None,
 584                                         quantity: None,
 585                                         payer_id: Some(&payer_pubkey()),
 586                                         payer_note: None,
 587                                 },
 588                         ),
 589                 );
 590
 591                 if let Err(e) = Refund::try_from(buffer) {
 592                         panic!("error parsing refund: {:?}", e);
 593                 }
 594         }
 595
 596         #[test]
 597         fn fails_building_refund_with_invalid_amount() {
 598                 match RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), MAX_VALUE_MSAT + 1) {
 599                         Ok(_) => panic!("expected error"),
 600                         Err(e) => assert_eq!(e, SemanticError::InvalidAmount),
 601                 }
 602         }
 603
 604         #[test]
 605         fn builds_refund_with_absolute_expiry() {
 606                 let future_expiry = Duration::from_secs(u64::max_value());
 607                 let past_expiry = Duration::from_secs(0);
 608
 609                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 610                         .absolute_expiry(future_expiry)
 611                         .build()
 612                         .unwrap();
 613                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 614                 #[cfg(feature = "std")]
 615                 assert!(!refund.is_expired());
 616                 assert_eq!(refund.absolute_expiry(), Some(future_expiry));
 617                 assert_eq!(tlv_stream.absolute_expiry, Some(future_expiry.as_secs()));
 618
 619                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 620                         .absolute_expiry(future_expiry)
 621                         .absolute_expiry(past_expiry)
 622                         .build()
 623                         .unwrap();
 624                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 625                 #[cfg(feature = "std")]
 626                 assert!(refund.is_expired());
 627                 assert_eq!(refund.absolute_expiry(), Some(past_expiry));
 628                 assert_eq!(tlv_stream.absolute_expiry, Some(past_expiry.as_secs()));
 629         }
 630
 631         #[test]
 632         fn builds_refund_with_paths() {
 633                 let paths = vec![
 634                         BlindedPath {
 635                                 introduction_node_id: pubkey(40),
 636                                 blinding_point: pubkey(41),
 637                                 blinded_hops: vec![
 638                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
 639                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
 640                                 ],
 641                         },
 642                         BlindedPath {
 643                                 introduction_node_id: pubkey(40),
 644                                 blinding_point: pubkey(41),
 645                                 blinded_hops: vec![
 646                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
 647                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
 648                                 ],
 649                         },
 650                 ];
 651
 652                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 653                         .path(paths[0].clone())
 654                         .path(paths[1].clone())
 655                         .build()
 656                         .unwrap();
 657                 let (_, offer_tlv_stream, invoice_request_tlv_stream) = refund.as_tlv_stream();
 658                 assert_eq!(refund.paths(), paths.as_slice());
 659                 assert_eq!(refund.payer_id(), pubkey(42));
 660                 assert_ne!(pubkey(42), pubkey(44));
 661                 assert_eq!(offer_tlv_stream.paths, Some(&paths));
 662                 assert_eq!(invoice_request_tlv_stream.payer_id, Some(&pubkey(42)));
 663         }
 664
 665         #[test]
 666         fn builds_refund_with_issuer() {
 667                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 668                         .issuer("bar".into())
 669                         .build()
 670                         .unwrap();
 671                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 672                 assert_eq!(refund.issuer(), Some(PrintableString("bar")));
 673                 assert_eq!(tlv_stream.issuer, Some(&String::from("bar")));
 674
 675                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 676                         .issuer("bar".into())
 677                         .issuer("baz".into())
 678                         .build()
 679                         .unwrap();
 680                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 681                 assert_eq!(refund.issuer(), Some(PrintableString("baz")));
 682                 assert_eq!(tlv_stream.issuer, Some(&String::from("baz")));
 683         }
 684
 685         #[test]
 686         fn builds_refund_with_chain() {
 687                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
 688                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
 689
 690                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 691                         .chain(Network::Bitcoin)
 692                         .build().unwrap();
 693                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 694                 assert_eq!(refund.chain(), mainnet);
 695                 assert_eq!(tlv_stream.chain, None);
 696
 697                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 698                         .chain(Network::Testnet)
 699                         .build().unwrap();
 700                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 701                 assert_eq!(refund.chain(), testnet);
 702                 assert_eq!(tlv_stream.chain, Some(&testnet));
 703
 704                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 705                         .chain(Network::Regtest)
 706                         .chain(Network::Testnet)
 707                         .build().unwrap();
 708                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 709                 assert_eq!(refund.chain(), testnet);
 710                 assert_eq!(tlv_stream.chain, Some(&testnet));
 711         }
 712
 713         #[test]
 714         fn builds_refund_with_payer_note() {
 715                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 716                         .payer_note("bar".into())
 717                         .build().unwrap();
 718                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 719                 assert_eq!(refund.payer_note(), Some(PrintableString("bar")));
 720                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
 721
 722                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 723                         .payer_note("bar".into())
 724                         .payer_note("baz".into())
 725                         .build().unwrap();
 726                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 727                 assert_eq!(refund.payer_note(), Some(PrintableString("baz")));
 728                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
 729         }
 730
 731         #[test]
 732         fn parses_refund_with_metadata() {
 733                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 734                         .build().unwrap();
 735                 if let Err(e) = refund.to_string().parse::<Refund>() {
 736                         panic!("error parsing refund: {:?}", e);
 737                 }
 738
 739                 let mut tlv_stream = refund.as_tlv_stream();
 740                 tlv_stream.0.metadata = None;
 741
 742                 match Refund::try_from(tlv_stream.to_bytes()) {
 743                         Ok(_) => panic!("expected error"),
 744                         Err(e) => {
 745                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPayerMetadata));
 746                         },
 747                 }
 748         }
 749
 750         #[test]
 751         fn parses_refund_with_description() {
 752                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 753                         .build().unwrap();
 754                 if let Err(e) = refund.to_string().parse::<Refund>() {
 755                         panic!("error parsing refund: {:?}", e);
 756                 }
 757
 758                 let mut tlv_stream = refund.as_tlv_stream();
 759                 tlv_stream.1.description = None;
 760
 761                 match Refund::try_from(tlv_stream.to_bytes()) {
 762                         Ok(_) => panic!("expected error"),
 763                         Err(e) => {
 764                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingDescription));
 765                         },
 766                 }
 767         }
 768
 769         #[test]
 770         fn parses_refund_with_amount() {
 771                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 772                         .build().unwrap();
 773                 if let Err(e) = refund.to_string().parse::<Refund>() {
 774                         panic!("error parsing refund: {:?}", e);
 775                 }
 776
 777                 let mut tlv_stream = refund.as_tlv_stream();
 778                 tlv_stream.2.amount = None;
 779
 780                 match Refund::try_from(tlv_stream.to_bytes()) {
 781                         Ok(_) => panic!("expected error"),
 782                         Err(e) => {
 783                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingAmount));
 784                         },
 785                 }
 786
 787                 let mut tlv_stream = refund.as_tlv_stream();
 788                 tlv_stream.2.amount = Some(MAX_VALUE_MSAT + 1);
 789
 790                 match Refund::try_from(tlv_stream.to_bytes()) {
 791                         Ok(_) => panic!("expected error"),
 792                         Err(e) => {
 793                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::InvalidAmount));
 794                         },
 795                 }
 796         }
 797
 798         #[test]
 799         fn parses_refund_with_payer_id() {
 800                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 801                         .build().unwrap();
 802                 if let Err(e) = refund.to_string().parse::<Refund>() {
 803                         panic!("error parsing refund: {:?}", e);
 804                 }
 805
 806                 let mut tlv_stream = refund.as_tlv_stream();
 807                 tlv_stream.2.payer_id = None;
 808
 809                 match Refund::try_from(tlv_stream.to_bytes()) {
 810                         Ok(_) => panic!("expected error"),
 811                         Err(e) => {
 812                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPayerId));
 813                         },
 814                 }
 815         }
 816
 817         #[test]
 818         fn parses_refund_with_optional_fields() {
 819                 let past_expiry = Duration::from_secs(0);
 820                 let paths = vec![
 821                         BlindedPath {
 822                                 introduction_node_id: pubkey(40),
 823                                 blinding_point: pubkey(41),
 824                                 blinded_hops: vec![
 825                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
 826                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
 827                                 ],
 828                         },
 829                         BlindedPath {
 830                                 introduction_node_id: pubkey(40),
 831                                 blinding_point: pubkey(41),
 832                                 blinded_hops: vec![
 833                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
 834                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
 835                                 ],
 836                         },
 837                 ];
 838
 839                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 840                         .absolute_expiry(past_expiry)
 841                         .issuer("bar".into())
 842                         .path(paths[0].clone())
 843                         .path(paths[1].clone())
 844                         .chain(Network::Testnet)
 845                         .features_unchecked(InvoiceRequestFeatures::unknown())
 846                         .payer_note("baz".into())
 847                         .build()
 848                         .unwrap();
 849                 match refund.to_string().parse::<Refund>() {
 850                         Ok(refund) => {
 851                                 assert_eq!(refund.absolute_expiry(), Some(past_expiry));
 852                                 #[cfg(feature = "std")]
 853                                 assert!(refund.is_expired());
 854                                 assert_eq!(refund.paths(), &paths[..]);
 855                                 assert_eq!(refund.issuer(), Some(PrintableString("bar")));
 856                                 assert_eq!(refund.chain(), ChainHash::using_genesis_block(Network::Testnet));
 857                                 assert_eq!(refund.features(), &InvoiceRequestFeatures::unknown());
 858                                 assert_eq!(refund.payer_note(), Some(PrintableString("baz")));
 859                         },
 860                         Err(e) => panic!("error parsing refund: {:?}", e),
 861                 }
 862         }
 863
 864         #[test]
 865         fn fails_parsing_refund_with_unexpected_fields() {
 866                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 867                         .build().unwrap();
 868                 if let Err(e) = refund.to_string().parse::<Refund>() {
 869                         panic!("error parsing refund: {:?}", e);
 870                 }
 871
 872                 let chains = vec![ChainHash::using_genesis_block(Network::Testnet)];
 873                 let mut tlv_stream = refund.as_tlv_stream();
 874                 tlv_stream.1.chains = Some(&chains);
 875
 876                 match Refund::try_from(tlv_stream.to_bytes()) {
 877                         Ok(_) => panic!("expected error"),
 878                         Err(e) => {
 879                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedChain));
 880                         },
 881                 }
 882
 883                 let mut tlv_stream = refund.as_tlv_stream();
 884                 tlv_stream.1.currency = Some(&b"USD");
 885                 tlv_stream.1.amount = Some(1000);
 886
 887                 match Refund::try_from(tlv_stream.to_bytes()) {
 888                         Ok(_) => panic!("expected error"),
 889                         Err(e) => {
 890                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedAmount));
 891                         },
 892                 }
 893
 894                 let features = OfferFeatures::unknown();
 895                 let mut tlv_stream = refund.as_tlv_stream();
 896                 tlv_stream.1.features = Some(&features);
 897
 898                 match Refund::try_from(tlv_stream.to_bytes()) {
 899                         Ok(_) => panic!("expected error"),
 900                         Err(e) => {
 901                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedFeatures));
 902                         },
 903                 }
 904
 905                 let mut tlv_stream = refund.as_tlv_stream();
 906                 tlv_stream.1.quantity_max = Some(10);
 907
 908                 match Refund::try_from(tlv_stream.to_bytes()) {
 909                         Ok(_) => panic!("expected error"),
 910                         Err(e) => {
 911                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedQuantity));
 912                         },
 913                 }
 914
 915                 let node_id = payer_pubkey();
 916                 let mut tlv_stream = refund.as_tlv_stream();
 917                 tlv_stream.1.node_id = Some(&node_id);
 918
 919                 match Refund::try_from(tlv_stream.to_bytes()) {
 920                         Ok(_) => panic!("expected error"),
 921                         Err(e) => {
 922                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedSigningPubkey));
 923                         },
 924                 }
 925
 926                 let mut tlv_stream = refund.as_tlv_stream();
 927                 tlv_stream.2.quantity = Some(10);
 928
 929                 match Refund::try_from(tlv_stream.to_bytes()) {
 930                         Ok(_) => panic!("expected error"),
 931                         Err(e) => {
 932                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedQuantity));
 933                         },
 934                 }
 935         }
 936
 937         #[test]
 938         fn fails_parsing_refund_with_extra_tlv_records() {
 939                 let secp_ctx = Secp256k1::new();
 940                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
 941                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], keys.public_key(), 1000).unwrap()
 942                         .build().unwrap();
 943
 944                 let mut encoded_refund = Vec::new();
 945                 refund.write(&mut encoded_refund).unwrap();
 946                 BigSize(1002).write(&mut encoded_refund).unwrap();
 947                 BigSize(32).write(&mut encoded_refund).unwrap();
 948                 [42u8; 32].write(&mut encoded_refund).unwrap();
 949
 950                 match Refund::try_from(encoded_refund) {
 951                         Ok(_) => panic!("expected error"),
 952                         Err(e) => assert_eq!(e, ParseError::Decode(DecodeError::InvalidValue)),
 953                 }
 954         }
 955 }