_ 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::PaymentHash;
  82 use crate::ln::features::InvoiceRequestFeatures;
  83 use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
  84 use crate::offers::invoice::{BlindedPayInfo, InvoiceBuilder};
  85 use crate::offers::invoice_request::{InvoiceRequestTlvStream, InvoiceRequestTlvStreamRef};
  86 use crate::offers::offer::{OfferTlvStream, OfferTlvStreamRef};
  87 use crate::offers::parse::{Bech32Encode, ParseError, ParsedMessage, SemanticError};
  88 use crate::offers::payer::{PayerContents, PayerTlvStream, PayerTlvStreamRef};
  89 use crate::onion_message::BlindedPath;
  90 use crate::util::ser::{SeekReadable, WithoutLength, Writeable, Writer};
  91 use crate::util::string::PrintableString;
  92
  93 use crate::prelude::*;
  94
  95 #[cfg(feature = "std")]
  96 use std::time::SystemTime;
  97
  98 /// Builds a [`Refund`] for the "offer for money" flow.
  99 ///
 100 /// See [module-level documentation] for usage.
 101 ///
 102 /// [module-level documentation]: self
 103 pub struct RefundBuilder {
 104         refund: RefundContents,
 105 }
 106
 107 impl RefundBuilder {
 108         /// Creates a new builder for a refund using the [`Refund::payer_id`] for the public node id to
 109         /// send to if no [`Refund::paths`] are set. Otherwise, it may be a transient pubkey.
 110         ///
 111         /// Additionally, sets the required [`Refund::description`], [`Refund::metadata`], and
 112         /// [`Refund::amount_msats`].
 113         pub fn new(
 114                 description: String, metadata: Vec<u8>, payer_id: PublicKey, amount_msats: u64
 115         ) -> Result<Self, SemanticError> {
 116                 if amount_msats > MAX_VALUE_MSAT {
 117                         return Err(SemanticError::InvalidAmount);
 118                 }
 119
 120                 let refund = RefundContents {
 121                         payer: PayerContents(metadata), description, absolute_expiry: None, issuer: None,
 122                         paths: None, chain: None, amount_msats, features: InvoiceRequestFeatures::empty(),
 123                         quantity: None, payer_id, payer_note: None,
 124                 };
 125
 126                 Ok(RefundBuilder { refund })
 127         }
 128
 129         /// Sets the [`Refund::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
 130         /// already passed is valid and can be checked for using [`Refund::is_expired`].
 131         ///
 132         /// Successive calls to this method will override the previous setting.
 133         pub fn absolute_expiry(mut self, absolute_expiry: Duration) -> Self {
 134                 self.refund.absolute_expiry = Some(absolute_expiry);
 135                 self
 136         }
 137
 138         /// Sets the [`Refund::issuer`].
 139         ///
 140         /// Successive calls to this method will override the previous setting.
 141         pub fn issuer(mut self, issuer: String) -> Self {
 142                 self.refund.issuer = Some(issuer);
 143                 self
 144         }
 145
 146         /// Adds a blinded path to [`Refund::paths`]. Must include at least one path if only connected
 147         /// by private channels or if [`Refund::payer_id`] is not a public node id.
 148         ///
 149         /// Successive calls to this method will add another blinded path. Caller is responsible for not
 150         /// adding duplicate paths.
 151         pub fn path(mut self, path: BlindedPath) -> Self {
 152                 self.refund.paths.get_or_insert_with(Vec::new).push(path);
 153                 self
 154         }
 155
 156         /// Sets the [`Refund::chain`] of the given [`Network`] for paying an invoice. If not
 157         /// called, [`Network::Bitcoin`] is assumed.
 158         ///
 159         /// Successive calls to this method will override the previous setting.
 160         pub fn chain(mut self, network: Network) -> Self {
 161                 self.refund.chain = Some(ChainHash::using_genesis_block(network));
 162                 self
 163         }
 164
 165         /// Sets [`Refund::quantity`] of items. This is purely for informational purposes. It is useful
 166         /// when the refund pertains to an [`Invoice`] that paid for more than one item from an
 167         /// [`Offer`] as specified by [`InvoiceRequest::quantity`].
 168         ///
 169         /// Successive calls to this method will override the previous setting.
 170         ///
 171         /// [`Invoice`]: crate::offers::invoice::Invoice
 172         /// [`InvoiceRequest::quantity`]: crate::offers::invoice_request::InvoiceRequest::quantity
 173         /// [`Offer`]: crate::offers::offer::Offer
 174         pub fn quantity(mut self, quantity: u64) -> Self {
 175                 self.refund.quantity = Some(quantity);
 176                 self
 177         }
 178
 179         /// Sets the [`Refund::payer_note`].
 180         ///
 181         /// Successive calls to this method will override the previous setting.
 182         pub fn payer_note(mut self, payer_note: String) -> Self {
 183                 self.refund.payer_note = Some(payer_note);
 184                 self
 185         }
 186
 187         /// Builds a [`Refund`] after checking for valid semantics.
 188         pub fn build(mut self) -> Result<Refund, SemanticError> {
 189                 if self.refund.chain() == self.refund.implied_chain() {
 190                         self.refund.chain = None;
 191                 }
 192
 193                 let mut bytes = Vec::new();
 194                 self.refund.write(&mut bytes).unwrap();
 195
 196                 Ok(Refund {
 197                         bytes,
 198                         contents: self.refund,
 199                 })
 200         }
 201 }
 202
 203 #[cfg(test)]
 204 impl RefundBuilder {
 205         fn features_unchecked(mut self, features: InvoiceRequestFeatures) -> Self {
 206                 self.refund.features = features;
 207                 self
 208         }
 209 }
 210
 211 /// A `Refund` is a request to send an [`Invoice`] without a preceding [`Offer`].
 212 ///
 213 /// Typically, after an invoice is paid, the recipient may publish a refund allowing the sender to
 214 /// recoup their funds. A refund may be used more generally as an "offer for money", such as with a
 215 /// bitcoin ATM.
 216 ///
 217 /// [`Invoice`]: crate::offers::invoice::Invoice
 218 /// [`Offer`]: crate::offers::offer::Offer
 219 #[derive(Clone, Debug)]
 220 pub struct Refund {
 221         pub(super) bytes: Vec<u8>,
 222         pub(super) contents: RefundContents,
 223 }
 224
 225 /// The contents of a [`Refund`], which may be shared with an [`Invoice`].
 226 ///
 227 /// [`Invoice`]: crate::offers::invoice::Invoice
 228 #[derive(Clone, Debug)]
 229 pub(super) struct RefundContents {
 230         payer: PayerContents,
 231         // offer fields
 232         description: String,
 233         absolute_expiry: Option<Duration>,
 234         issuer: Option<String>,
 235         paths: Option<Vec<BlindedPath>>,
 236         // invoice_request fields
 237         chain: Option<ChainHash>,
 238         amount_msats: u64,
 239         features: InvoiceRequestFeatures,
 240         quantity: Option<u64>,
 241         payer_id: PublicKey,
 242         payer_note: Option<String>,
 243 }
 244
 245 impl Refund {
 246         /// A complete description of the purpose of the refund. Intended to be displayed to the user
 247         /// but with the caveat that it has not been verified in any way.
 248         pub fn description(&self) -> PrintableString {
 249                 PrintableString(&self.contents.description)
 250         }
 251
 252         /// Duration since the Unix epoch when an invoice should no longer be sent.
 253         ///
 254         /// If `None`, the refund does not expire.
 255         pub fn absolute_expiry(&self) -> Option<Duration> {
 256                 self.contents.absolute_expiry
 257         }
 258
 259         /// Whether the refund has expired.
 260         #[cfg(feature = "std")]
 261         pub fn is_expired(&self) -> bool {
 262                 self.contents.is_expired()
 263         }
 264
 265         /// The issuer of the refund, possibly beginning with `user@domain` or `domain`. Intended to be
 266         /// displayed to the user but with the caveat that it has not been verified in any way.
 267         pub fn issuer(&self) -> Option<PrintableString> {
 268                 self.contents.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 269         }
 270
 271         /// Paths to the sender originating from publicly reachable nodes. Blinded paths provide sender
 272         /// privacy by obfuscating its node id.
 273         pub fn paths(&self) -> &[BlindedPath] {
 274                 self.contents.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 275         }
 276
 277         /// An unpredictable series of bytes, typically containing information about the derivation of
 278         /// [`payer_id`].
 279         ///
 280         /// [`payer_id`]: Self::payer_id
 281         pub fn metadata(&self) -> &[u8] {
 282                 &self.contents.payer.0
 283         }
 284
 285         /// A chain that the refund is valid for.
 286         pub fn chain(&self) -> ChainHash {
 287                 self.contents.chain.unwrap_or_else(|| self.contents.implied_chain())
 288         }
 289
 290         /// The amount to refund in msats (i.e., the minimum lightning-payable unit for [`chain`]).
 291         ///
 292         /// [`chain`]: Self::chain
 293         pub fn amount_msats(&self) -> u64 {
 294                 self.contents.amount_msats
 295         }
 296
 297         /// Features pertaining to requesting an invoice.
 298         pub fn features(&self) -> &InvoiceRequestFeatures {
 299                 &self.contents.features
 300         }
 301
 302         /// The quantity of an item that refund is for.
 303         pub fn quantity(&self) -> Option<u64> {
 304                 self.contents.quantity
 305         }
 306
 307         /// A public node id to send to in the case where there are no [`paths`]. Otherwise, a possibly
 308         /// transient pubkey.
 309         ///
 310         /// [`paths`]: Self::paths
 311         pub fn payer_id(&self) -> PublicKey {
 312                 self.contents.payer_id
 313         }
 314
 315         /// Payer provided note to include in the invoice.
 316         pub fn payer_note(&self) -> Option<PrintableString> {
 317                 self.contents.payer_note.as_ref().map(|payer_note| PrintableString(payer_note.as_str()))
 318         }
 319
 320         /// Creates an [`Invoice`] for the refund with the given required fields.
 321         ///
 322         /// Unless [`InvoiceBuilder::relative_expiry`] is set, the invoice will expire two hours after
 323         /// calling this method in `std` builds. For `no-std` builds, a final [`Duration`] parameter
 324         /// must be given, which is used to set [`Invoice::created_at`] since [`std::time::SystemTime`]
 325         /// is not available.
 326         ///
 327         /// The caller is expected to remember the preimage of `payment_hash` in order to
 328         /// claim a payment for the invoice.
 329         ///
 330         /// The `signing_pubkey` is required to sign the invoice since refunds are not in response to an
 331         /// offer, which does have a `signing_pubkey`.
 332         ///
 333         /// The `payment_paths` parameter is useful for maintaining the payment recipient's privacy. It
 334         /// must contain one or more elements ordered from most-preferred to least-preferred, if there's
 335         /// a preference. Note, however, that any privacy is lost if a public node id is used for
 336         /// `signing_pubkey`.
 337         ///
 338         /// Errors if the request contains unknown required features.
 339         ///
 340         /// [`Invoice`]: crate::offers::invoice::Invoice
 341         /// [`Invoice::created_at`]: crate::offers::invoice::Invoice::created_at
 342         pub fn respond_with(
 343                 &self, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>, payment_hash: PaymentHash,
 344                 signing_pubkey: PublicKey,
 345                 #[cfg(any(test, not(feature = "std")))]
 346                 created_at: Duration
 347         ) -> Result<InvoiceBuilder, SemanticError> {
 348                 if self.features().requires_unknown_bits() {
 349                         return Err(SemanticError::UnknownRequiredFeatures);
 350                 }
 351
 352                 #[cfg(all(not(test), feature = "std"))]
 353                 let created_at = std::time::SystemTime::now()
 354                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 355                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 356
 357                 InvoiceBuilder::for_refund(self, payment_paths, created_at, payment_hash, signing_pubkey)
 358         }
 359
 360         #[cfg(test)]
 361         fn as_tlv_stream(&self) -> RefundTlvStreamRef {
 362                 self.contents.as_tlv_stream()
 363         }
 364 }
 365
 366 impl AsRef<[u8]> for Refund {
 367         fn as_ref(&self) -> &[u8] {
 368                 &self.bytes
 369         }
 370 }
 371
 372 impl RefundContents {
 373         #[cfg(feature = "std")]
 374         pub(super) fn is_expired(&self) -> bool {
 375                 match self.absolute_expiry {
 376                         Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() {
 377                                 Ok(elapsed) => elapsed > seconds_from_epoch,
 378                                 Err(_) => false,
 379                         },
 380                         None => false,
 381                 }
 382         }
 383
 384         pub(super) fn chain(&self) -> ChainHash {
 385                 self.chain.unwrap_or_else(|| self.implied_chain())
 386         }
 387
 388         pub fn implied_chain(&self) -> ChainHash {
 389                 ChainHash::using_genesis_block(Network::Bitcoin)
 390         }
 391
 392         pub(super) fn as_tlv_stream(&self) -> RefundTlvStreamRef {
 393                 let payer = PayerTlvStreamRef {
 394                         metadata: Some(&self.payer.0),
 395                 };
 396
 397                 let offer = OfferTlvStreamRef {
 398                         chains: None,
 399                         metadata: None,
 400                         currency: None,
 401                         amount: None,
 402                         description: Some(&self.description),
 403                         features: None,
 404                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 405                         paths: self.paths.as_ref(),
 406                         issuer: self.issuer.as_ref(),
 407                         quantity_max: None,
 408                         node_id: None,
 409                 };
 410
 411                 let features = {
 412                         if self.features == InvoiceRequestFeatures::empty() { None }
 413                         else { Some(&self.features) }
 414                 };
 415
 416                 let invoice_request = InvoiceRequestTlvStreamRef {
 417                         chain: self.chain.as_ref(),
 418                         amount: Some(self.amount_msats),
 419                         features,
 420                         quantity: self.quantity,
 421                         payer_id: Some(&self.payer_id),
 422                         payer_note: self.payer_note.as_ref(),
 423                 };
 424
 425                 (payer, offer, invoice_request)
 426         }
 427 }
 428
 429 impl Writeable for Refund {
 430         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 431                 WithoutLength(&self.bytes).write(writer)
 432         }
 433 }
 434
 435 impl Writeable for RefundContents {
 436         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 437                 self.as_tlv_stream().write(writer)
 438         }
 439 }
 440
 441 type RefundTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
 442
 443 type RefundTlvStreamRef<'a> = (
 444         PayerTlvStreamRef<'a>,
 445         OfferTlvStreamRef<'a>,
 446         InvoiceRequestTlvStreamRef<'a>,
 447 );
 448
 449 impl SeekReadable for RefundTlvStream {
 450         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 451                 let payer = SeekReadable::read(r)?;
 452                 let offer = SeekReadable::read(r)?;
 453                 let invoice_request = SeekReadable::read(r)?;
 454
 455                 Ok((payer, offer, invoice_request))
 456         }
 457 }
 458
 459 impl Bech32Encode for Refund {
 460         const BECH32_HRP: &'static str = "lnr";
 461 }
 462
 463 impl FromStr for Refund {
 464         type Err = ParseError;
 465
 466         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 467                 Refund::from_bech32_str(s)
 468         }
 469 }
 470
 471 impl TryFrom<Vec<u8>> for Refund {
 472         type Error = ParseError;
 473
 474         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 475                 let refund = ParsedMessage::<RefundTlvStream>::try_from(bytes)?;
 476                 let ParsedMessage { bytes, tlv_stream } = refund;
 477                 let contents = RefundContents::try_from(tlv_stream)?;
 478
 479                 Ok(Refund { bytes, contents })
 480         }
 481 }
 482
 483 impl TryFrom<RefundTlvStream> for RefundContents {
 484         type Error = SemanticError;
 485
 486         fn try_from(tlv_stream: RefundTlvStream) -> Result<Self, Self::Error> {
 487                 let (
 488                         PayerTlvStream { metadata: payer_metadata },
 489                         OfferTlvStream {
 490                                 chains, metadata, currency, amount: offer_amount, description,
 491                                 features: offer_features, absolute_expiry, paths, issuer, quantity_max, node_id,
 492                         },
 493                         InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
 494                 ) = tlv_stream;
 495
 496                 let payer = match payer_metadata {
 497                         None => return Err(SemanticError::MissingPayerMetadata),
 498                         Some(metadata) => PayerContents(metadata),
 499                 };
 500
 501                 if metadata.is_some() {
 502                         return Err(SemanticError::UnexpectedMetadata);
 503                 }
 504
 505                 if chains.is_some() {
 506                         return Err(SemanticError::UnexpectedChain);
 507                 }
 508
 509                 if currency.is_some() || offer_amount.is_some() {
 510                         return Err(SemanticError::UnexpectedAmount);
 511                 }
 512
 513                 let description = match description {
 514                         None => return Err(SemanticError::MissingDescription),
 515                         Some(description) => description,
 516                 };
 517
 518                 if offer_features.is_some() {
 519                         return Err(SemanticError::UnexpectedFeatures);
 520                 }
 521
 522                 let absolute_expiry = absolute_expiry.map(Duration::from_secs);
 523
 524                 if quantity_max.is_some() {
 525                         return Err(SemanticError::UnexpectedQuantity);
 526                 }
 527
 528                 if node_id.is_some() {
 529                         return Err(SemanticError::UnexpectedSigningPubkey);
 530                 }
 531
 532                 let amount_msats = match amount {
 533                         None => return Err(SemanticError::MissingAmount),
 534                         Some(amount_msats) if amount_msats > MAX_VALUE_MSAT => {
 535                                 return Err(SemanticError::InvalidAmount);
 536                         },
 537                         Some(amount_msats) => amount_msats,
 538                 };
 539
 540                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
 541
 542                 let payer_id = match payer_id {
 543                         None => return Err(SemanticError::MissingPayerId),
 544                         Some(payer_id) => payer_id,
 545                 };
 546
 547                 Ok(RefundContents {
 548                         payer, description, absolute_expiry, issuer, paths, chain, amount_msats, features,
 549                         quantity, payer_id, payer_note,
 550                 })
 551         }
 552 }
 553
 554 impl core::fmt::Display for Refund {
 555         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 556                 self.fmt_bech32_str(f)
 557         }
 558 }
 559
 560 #[cfg(test)]
 561 mod tests {
 562         use super::{Refund, RefundBuilder, RefundTlvStreamRef};
 563
 564         use bitcoin::blockdata::constants::ChainHash;
 565         use bitcoin::network::constants::Network;
 566         use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
 567         use core::convert::TryFrom;
 568         use core::time::Duration;
 569         use crate::ln::features::{InvoiceRequestFeatures, OfferFeatures};
 570         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 571         use crate::offers::invoice_request::InvoiceRequestTlvStreamRef;
 572         use crate::offers::offer::OfferTlvStreamRef;
 573         use crate::offers::parse::{ParseError, SemanticError};
 574         use crate::offers::payer::PayerTlvStreamRef;
 575         use crate::onion_message::{BlindedHop, BlindedPath};
 576         use crate::util::ser::{BigSize, Writeable};
 577         use crate::util::string::PrintableString;
 578
 579         fn payer_pubkey() -> PublicKey {
 580                 let secp_ctx = Secp256k1::new();
 581                 KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()).public_key()
 582         }
 583
 584         fn pubkey(byte: u8) -> PublicKey {
 585                 let secp_ctx = Secp256k1::new();
 586                 PublicKey::from_secret_key(&secp_ctx, &privkey(byte))
 587         }
 588
 589         fn privkey(byte: u8) -> SecretKey {
 590                 SecretKey::from_slice(&[byte; 32]).unwrap()
 591         }
 592
 593         trait ToBytes {
 594                 fn to_bytes(&self) -> Vec<u8>;
 595         }
 596
 597         impl<'a> ToBytes for RefundTlvStreamRef<'a> {
 598                 fn to_bytes(&self) -> Vec<u8> {
 599                         let mut buffer = Vec::new();
 600                         self.write(&mut buffer).unwrap();
 601                         buffer
 602                 }
 603         }
 604
 605         #[test]
 606         fn builds_refund_with_defaults() {
 607                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 608                         .build().unwrap();
 609
 610                 let mut buffer = Vec::new();
 611                 refund.write(&mut buffer).unwrap();
 612
 613                 assert_eq!(refund.bytes, buffer.as_slice());
 614                 assert_eq!(refund.metadata(), &[1; 32]);
 615                 assert_eq!(refund.description(), PrintableString("foo"));
 616                 assert_eq!(refund.absolute_expiry(), None);
 617                 #[cfg(feature = "std")]
 618                 assert!(!refund.is_expired());
 619                 assert_eq!(refund.paths(), &[]);
 620                 assert_eq!(refund.issuer(), None);
 621                 assert_eq!(refund.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
 622                 assert_eq!(refund.amount_msats(), 1000);
 623                 assert_eq!(refund.features(), &InvoiceRequestFeatures::empty());
 624                 assert_eq!(refund.payer_id(), payer_pubkey());
 625                 assert_eq!(refund.payer_note(), None);
 626
 627                 assert_eq!(
 628                         refund.as_tlv_stream(),
 629                         (
 630                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
 631                                 OfferTlvStreamRef {
 632                                         chains: None,
 633                                         metadata: None,
 634                                         currency: None,
 635                                         amount: None,
 636                                         description: Some(&String::from("foo")),
 637                                         features: None,
 638                                         absolute_expiry: None,
 639                                         paths: None,
 640                                         issuer: None,
 641                                         quantity_max: None,
 642                                         node_id: None,
 643                                 },
 644                                 InvoiceRequestTlvStreamRef {
 645                                         chain: None,
 646                                         amount: Some(1000),
 647                                         features: None,
 648                                         quantity: None,
 649                                         payer_id: Some(&payer_pubkey()),
 650                                         payer_note: None,
 651                                 },
 652                         ),
 653                 );
 654
 655                 if let Err(e) = Refund::try_from(buffer) {
 656                         panic!("error parsing refund: {:?}", e);
 657                 }
 658         }
 659
 660         #[test]
 661         fn fails_building_refund_with_invalid_amount() {
 662                 match RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), MAX_VALUE_MSAT + 1) {
 663                         Ok(_) => panic!("expected error"),
 664                         Err(e) => assert_eq!(e, SemanticError::InvalidAmount),
 665                 }
 666         }
 667
 668         #[test]
 669         fn builds_refund_with_absolute_expiry() {
 670                 let future_expiry = Duration::from_secs(u64::max_value());
 671                 let past_expiry = Duration::from_secs(0);
 672
 673                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 674                         .absolute_expiry(future_expiry)
 675                         .build()
 676                         .unwrap();
 677                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 678                 #[cfg(feature = "std")]
 679                 assert!(!refund.is_expired());
 680                 assert_eq!(refund.absolute_expiry(), Some(future_expiry));
 681                 assert_eq!(tlv_stream.absolute_expiry, Some(future_expiry.as_secs()));
 682
 683                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 684                         .absolute_expiry(future_expiry)
 685                         .absolute_expiry(past_expiry)
 686                         .build()
 687                         .unwrap();
 688                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 689                 #[cfg(feature = "std")]
 690                 assert!(refund.is_expired());
 691                 assert_eq!(refund.absolute_expiry(), Some(past_expiry));
 692                 assert_eq!(tlv_stream.absolute_expiry, Some(past_expiry.as_secs()));
 693         }
 694
 695         #[test]
 696         fn builds_refund_with_paths() {
 697                 let paths = vec![
 698                         BlindedPath {
 699                                 introduction_node_id: pubkey(40),
 700                                 blinding_point: pubkey(41),
 701                                 blinded_hops: vec![
 702                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
 703                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
 704                                 ],
 705                         },
 706                         BlindedPath {
 707                                 introduction_node_id: pubkey(40),
 708                                 blinding_point: pubkey(41),
 709                                 blinded_hops: vec![
 710                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
 711                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
 712                                 ],
 713                         },
 714                 ];
 715
 716                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 717                         .path(paths[0].clone())
 718                         .path(paths[1].clone())
 719                         .build()
 720                         .unwrap();
 721                 let (_, offer_tlv_stream, invoice_request_tlv_stream) = refund.as_tlv_stream();
 722                 assert_eq!(refund.paths(), paths.as_slice());
 723                 assert_eq!(refund.payer_id(), pubkey(42));
 724                 assert_ne!(pubkey(42), pubkey(44));
 725                 assert_eq!(offer_tlv_stream.paths, Some(&paths));
 726                 assert_eq!(invoice_request_tlv_stream.payer_id, Some(&pubkey(42)));
 727         }
 728
 729         #[test]
 730         fn builds_refund_with_issuer() {
 731                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 732                         .issuer("bar".into())
 733                         .build()
 734                         .unwrap();
 735                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 736                 assert_eq!(refund.issuer(), Some(PrintableString("bar")));
 737                 assert_eq!(tlv_stream.issuer, Some(&String::from("bar")));
 738
 739                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 740                         .issuer("bar".into())
 741                         .issuer("baz".into())
 742                         .build()
 743                         .unwrap();
 744                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 745                 assert_eq!(refund.issuer(), Some(PrintableString("baz")));
 746                 assert_eq!(tlv_stream.issuer, Some(&String::from("baz")));
 747         }
 748
 749         #[test]
 750         fn builds_refund_with_chain() {
 751                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
 752                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
 753
 754                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 755                         .chain(Network::Bitcoin)
 756                         .build().unwrap();
 757                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 758                 assert_eq!(refund.chain(), mainnet);
 759                 assert_eq!(tlv_stream.chain, None);
 760
 761                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 762                         .chain(Network::Testnet)
 763                         .build().unwrap();
 764                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 765                 assert_eq!(refund.chain(), testnet);
 766                 assert_eq!(tlv_stream.chain, Some(&testnet));
 767
 768                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 769                         .chain(Network::Regtest)
 770                         .chain(Network::Testnet)
 771                         .build().unwrap();
 772                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 773                 assert_eq!(refund.chain(), testnet);
 774                 assert_eq!(tlv_stream.chain, Some(&testnet));
 775         }
 776
 777         #[test]
 778         fn builds_refund_with_quantity() {
 779                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 780                         .quantity(10)
 781                         .build().unwrap();
 782                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 783                 assert_eq!(refund.quantity(), Some(10));
 784                 assert_eq!(tlv_stream.quantity, Some(10));
 785
 786                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 787                         .quantity(10)
 788                         .quantity(1)
 789                         .build().unwrap();
 790                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 791                 assert_eq!(refund.quantity(), Some(1));
 792                 assert_eq!(tlv_stream.quantity, Some(1));
 793         }
 794
 795         #[test]
 796         fn builds_refund_with_payer_note() {
 797                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 798                         .payer_note("bar".into())
 799                         .build().unwrap();
 800                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 801                 assert_eq!(refund.payer_note(), Some(PrintableString("bar")));
 802                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
 803
 804                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 805                         .payer_note("bar".into())
 806                         .payer_note("baz".into())
 807                         .build().unwrap();
 808                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 809                 assert_eq!(refund.payer_note(), Some(PrintableString("baz")));
 810                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
 811         }
 812
 813         #[test]
 814         fn parses_refund_with_metadata() {
 815                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 816                         .build().unwrap();
 817                 if let Err(e) = refund.to_string().parse::<Refund>() {
 818                         panic!("error parsing refund: {:?}", e);
 819                 }
 820
 821                 let mut tlv_stream = refund.as_tlv_stream();
 822                 tlv_stream.0.metadata = None;
 823
 824                 match Refund::try_from(tlv_stream.to_bytes()) {
 825                         Ok(_) => panic!("expected error"),
 826                         Err(e) => {
 827                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPayerMetadata));
 828                         },
 829                 }
 830         }
 831
 832         #[test]
 833         fn parses_refund_with_description() {
 834                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 835                         .build().unwrap();
 836                 if let Err(e) = refund.to_string().parse::<Refund>() {
 837                         panic!("error parsing refund: {:?}", e);
 838                 }
 839
 840                 let mut tlv_stream = refund.as_tlv_stream();
 841                 tlv_stream.1.description = None;
 842
 843                 match Refund::try_from(tlv_stream.to_bytes()) {
 844                         Ok(_) => panic!("expected error"),
 845                         Err(e) => {
 846                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingDescription));
 847                         },
 848                 }
 849         }
 850
 851         #[test]
 852         fn parses_refund_with_amount() {
 853                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 854                         .build().unwrap();
 855                 if let Err(e) = refund.to_string().parse::<Refund>() {
 856                         panic!("error parsing refund: {:?}", e);
 857                 }
 858
 859                 let mut tlv_stream = refund.as_tlv_stream();
 860                 tlv_stream.2.amount = None;
 861
 862                 match Refund::try_from(tlv_stream.to_bytes()) {
 863                         Ok(_) => panic!("expected error"),
 864                         Err(e) => {
 865                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingAmount));
 866                         },
 867                 }
 868
 869                 let mut tlv_stream = refund.as_tlv_stream();
 870                 tlv_stream.2.amount = Some(MAX_VALUE_MSAT + 1);
 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::InvalidAmount));
 876                         },
 877                 }
 878         }
 879
 880         #[test]
 881         fn parses_refund_with_payer_id() {
 882                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 883                         .build().unwrap();
 884                 if let Err(e) = refund.to_string().parse::<Refund>() {
 885                         panic!("error parsing refund: {:?}", e);
 886                 }
 887
 888                 let mut tlv_stream = refund.as_tlv_stream();
 889                 tlv_stream.2.payer_id = None;
 890
 891                 match Refund::try_from(tlv_stream.to_bytes()) {
 892                         Ok(_) => panic!("expected error"),
 893                         Err(e) => {
 894                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPayerId));
 895                         },
 896                 }
 897         }
 898
 899         #[test]
 900         fn parses_refund_with_optional_fields() {
 901                 let past_expiry = Duration::from_secs(0);
 902                 let paths = vec![
 903                         BlindedPath {
 904                                 introduction_node_id: pubkey(40),
 905                                 blinding_point: pubkey(41),
 906                                 blinded_hops: vec![
 907                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
 908                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
 909                                 ],
 910                         },
 911                         BlindedPath {
 912                                 introduction_node_id: pubkey(40),
 913                                 blinding_point: pubkey(41),
 914                                 blinded_hops: vec![
 915                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
 916                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
 917                                 ],
 918                         },
 919                 ];
 920
 921                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 922                         .absolute_expiry(past_expiry)
 923                         .issuer("bar".into())
 924                         .path(paths[0].clone())
 925                         .path(paths[1].clone())
 926                         .chain(Network::Testnet)
 927                         .features_unchecked(InvoiceRequestFeatures::unknown())
 928                         .quantity(10)
 929                         .payer_note("baz".into())
 930                         .build()
 931                         .unwrap();
 932                 match refund.to_string().parse::<Refund>() {
 933                         Ok(refund) => {
 934                                 assert_eq!(refund.absolute_expiry(), Some(past_expiry));
 935                                 #[cfg(feature = "std")]
 936                                 assert!(refund.is_expired());
 937                                 assert_eq!(refund.paths(), &paths[..]);
 938                                 assert_eq!(refund.issuer(), Some(PrintableString("bar")));
 939                                 assert_eq!(refund.chain(), ChainHash::using_genesis_block(Network::Testnet));
 940                                 assert_eq!(refund.features(), &InvoiceRequestFeatures::unknown());
 941                                 assert_eq!(refund.quantity(), Some(10));
 942                                 assert_eq!(refund.payer_note(), Some(PrintableString("baz")));
 943                         },
 944                         Err(e) => panic!("error parsing refund: {:?}", e),
 945                 }
 946         }
 947
 948         #[test]
 949         fn fails_parsing_refund_with_unexpected_fields() {
 950                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 951                         .build().unwrap();
 952                 if let Err(e) = refund.to_string().parse::<Refund>() {
 953                         panic!("error parsing refund: {:?}", e);
 954                 }
 955
 956                 let metadata = vec![42; 32];
 957                 let mut tlv_stream = refund.as_tlv_stream();
 958                 tlv_stream.1.metadata = Some(&metadata);
 959
 960                 match Refund::try_from(tlv_stream.to_bytes()) {
 961                         Ok(_) => panic!("expected error"),
 962                         Err(e) => {
 963                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedMetadata));
 964                         },
 965                 }
 966
 967                 let chains = vec![ChainHash::using_genesis_block(Network::Testnet)];
 968                 let mut tlv_stream = refund.as_tlv_stream();
 969                 tlv_stream.1.chains = Some(&chains);
 970
 971                 match Refund::try_from(tlv_stream.to_bytes()) {
 972                         Ok(_) => panic!("expected error"),
 973                         Err(e) => {
 974                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedChain));
 975                         },
 976                 }
 977
 978                 let mut tlv_stream = refund.as_tlv_stream();
 979                 tlv_stream.1.currency = Some(&b"USD");
 980                 tlv_stream.1.amount = Some(1000);
 981
 982                 match Refund::try_from(tlv_stream.to_bytes()) {
 983                         Ok(_) => panic!("expected error"),
 984                         Err(e) => {
 985                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedAmount));
 986                         },
 987                 }
 988
 989                 let features = OfferFeatures::unknown();
 990                 let mut tlv_stream = refund.as_tlv_stream();
 991                 tlv_stream.1.features = Some(&features);
 992
 993                 match Refund::try_from(tlv_stream.to_bytes()) {
 994                         Ok(_) => panic!("expected error"),
 995                         Err(e) => {
 996                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedFeatures));
 997                         },
 998                 }
 999
1000                 let mut tlv_stream = refund.as_tlv_stream();
1001                 tlv_stream.1.quantity_max = Some(10);
1002
1003                 match Refund::try_from(tlv_stream.to_bytes()) {
1004                         Ok(_) => panic!("expected error"),
1005                         Err(e) => {
1006                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedQuantity));
1007                         },
1008                 }
1009
1010                 let node_id = payer_pubkey();
1011                 let mut tlv_stream = refund.as_tlv_stream();
1012                 tlv_stream.1.node_id = Some(&node_id);
1013
1014                 match Refund::try_from(tlv_stream.to_bytes()) {
1015                         Ok(_) => panic!("expected error"),
1016                         Err(e) => {
1017                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedSigningPubkey));
1018                         },
1019                 }
1020         }
1021
1022         #[test]
1023         fn fails_parsing_refund_with_extra_tlv_records() {
1024                 let secp_ctx = Secp256k1::new();
1025                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1026                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], keys.public_key(), 1000).unwrap()
1027                         .build().unwrap();
1028
1029                 let mut encoded_refund = Vec::new();
1030                 refund.write(&mut encoded_refund).unwrap();
1031                 BigSize(1002).write(&mut encoded_refund).unwrap();
1032                 BigSize(32).write(&mut encoded_refund).unwrap();
1033                 [42u8; 32].write(&mut encoded_refund).unwrap();
1034
1035                 match Refund::try_from(encoded_refund) {
1036                         Ok(_) => panic!("expected error"),
1037                         Err(e) => assert_eq!(e, ParseError::Decode(DecodeError::InvalidValue)),
1038                 }
1039         }
1040 }