_ 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 //! ```
  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, PartialEq)]
 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, PartialEq)]
 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 and using the
 321         /// [`Duration`] since [`std::time::SystemTime::UNIX_EPOCH`] as the creation time.
 322         ///
 323         /// See [`Refund::respond_with_no_std`] for further details where the aforementioned creation
 324         /// time is used for the `created_at` parameter.
 325         ///
 326         /// [`Invoice`]: crate::offers::invoice::Invoice
 327         /// [`Duration`]: core::time::Duration
 328         #[cfg(feature = "std")]
 329         pub fn respond_with(
 330                 &self, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>, payment_hash: PaymentHash,
 331                 signing_pubkey: PublicKey,
 332         ) -> Result<InvoiceBuilder, SemanticError> {
 333                 let created_at = std::time::SystemTime::now()
 334                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 335                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 336
 337                 self.respond_with_no_std(payment_paths, payment_hash, signing_pubkey, created_at)
 338         }
 339
 340         /// Creates an [`Invoice`] for the refund with the given required fields.
 341         ///
 342         /// Unless [`InvoiceBuilder::relative_expiry`] is set, the invoice will expire two hours after
 343         /// `created_at`, which is used to set [`Invoice::created_at`]. Useful for `no-std` builds where
 344         /// [`std::time::SystemTime`] is not available.
 345         ///
 346         /// The caller is expected to remember the preimage of `payment_hash` in order to
 347         /// claim a payment for the invoice.
 348         ///
 349         /// The `signing_pubkey` is required to sign the invoice since refunds are not in response to an
 350         /// offer, which does have a `signing_pubkey`.
 351         ///
 352         /// The `payment_paths` parameter is useful for maintaining the payment recipient's privacy. It
 353         /// must contain one or more elements ordered from most-preferred to least-preferred, if there's
 354         /// a preference. Note, however, that any privacy is lost if a public node id is used for
 355         /// `signing_pubkey`.
 356         ///
 357         /// Errors if the request contains unknown required features.
 358         ///
 359         /// [`Invoice`]: crate::offers::invoice::Invoice
 360         /// [`Invoice::created_at`]: crate::offers::invoice::Invoice::created_at
 361         pub fn respond_with_no_std(
 362                 &self, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>, payment_hash: PaymentHash,
 363                 signing_pubkey: PublicKey, created_at: Duration
 364         ) -> Result<InvoiceBuilder, SemanticError> {
 365                 if self.features().requires_unknown_bits() {
 366                         return Err(SemanticError::UnknownRequiredFeatures);
 367                 }
 368
 369                 InvoiceBuilder::for_refund(self, payment_paths, created_at, payment_hash, signing_pubkey)
 370         }
 371
 372         #[cfg(test)]
 373         fn as_tlv_stream(&self) -> RefundTlvStreamRef {
 374                 self.contents.as_tlv_stream()
 375         }
 376 }
 377
 378 impl AsRef<[u8]> for Refund {
 379         fn as_ref(&self) -> &[u8] {
 380                 &self.bytes
 381         }
 382 }
 383
 384 impl RefundContents {
 385         #[cfg(feature = "std")]
 386         pub(super) fn is_expired(&self) -> bool {
 387                 match self.absolute_expiry {
 388                         Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() {
 389                                 Ok(elapsed) => elapsed > seconds_from_epoch,
 390                                 Err(_) => false,
 391                         },
 392                         None => false,
 393                 }
 394         }
 395
 396         pub(super) fn chain(&self) -> ChainHash {
 397                 self.chain.unwrap_or_else(|| self.implied_chain())
 398         }
 399
 400         pub fn implied_chain(&self) -> ChainHash {
 401                 ChainHash::using_genesis_block(Network::Bitcoin)
 402         }
 403
 404         pub(super) fn as_tlv_stream(&self) -> RefundTlvStreamRef {
 405                 let payer = PayerTlvStreamRef {
 406                         metadata: Some(&self.payer.0),
 407                 };
 408
 409                 let offer = OfferTlvStreamRef {
 410                         chains: None,
 411                         metadata: None,
 412                         currency: None,
 413                         amount: None,
 414                         description: Some(&self.description),
 415                         features: None,
 416                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 417                         paths: self.paths.as_ref(),
 418                         issuer: self.issuer.as_ref(),
 419                         quantity_max: None,
 420                         node_id: None,
 421                 };
 422
 423                 let features = {
 424                         if self.features == InvoiceRequestFeatures::empty() { None }
 425                         else { Some(&self.features) }
 426                 };
 427
 428                 let invoice_request = InvoiceRequestTlvStreamRef {
 429                         chain: self.chain.as_ref(),
 430                         amount: Some(self.amount_msats),
 431                         features,
 432                         quantity: self.quantity,
 433                         payer_id: Some(&self.payer_id),
 434                         payer_note: self.payer_note.as_ref(),
 435                 };
 436
 437                 (payer, offer, invoice_request)
 438         }
 439 }
 440
 441 impl Writeable for Refund {
 442         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 443                 WithoutLength(&self.bytes).write(writer)
 444         }
 445 }
 446
 447 impl Writeable for RefundContents {
 448         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 449                 self.as_tlv_stream().write(writer)
 450         }
 451 }
 452
 453 type RefundTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
 454
 455 type RefundTlvStreamRef<'a> = (
 456         PayerTlvStreamRef<'a>,
 457         OfferTlvStreamRef<'a>,
 458         InvoiceRequestTlvStreamRef<'a>,
 459 );
 460
 461 impl SeekReadable for RefundTlvStream {
 462         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 463                 let payer = SeekReadable::read(r)?;
 464                 let offer = SeekReadable::read(r)?;
 465                 let invoice_request = SeekReadable::read(r)?;
 466
 467                 Ok((payer, offer, invoice_request))
 468         }
 469 }
 470
 471 impl Bech32Encode for Refund {
 472         const BECH32_HRP: &'static str = "lnr";
 473 }
 474
 475 impl FromStr for Refund {
 476         type Err = ParseError;
 477
 478         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 479                 Refund::from_bech32_str(s)
 480         }
 481 }
 482
 483 impl TryFrom<Vec<u8>> for Refund {
 484         type Error = ParseError;
 485
 486         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 487                 let refund = ParsedMessage::<RefundTlvStream>::try_from(bytes)?;
 488                 let ParsedMessage { bytes, tlv_stream } = refund;
 489                 let contents = RefundContents::try_from(tlv_stream)?;
 490
 491                 Ok(Refund { bytes, contents })
 492         }
 493 }
 494
 495 impl TryFrom<RefundTlvStream> for RefundContents {
 496         type Error = SemanticError;
 497
 498         fn try_from(tlv_stream: RefundTlvStream) -> Result<Self, Self::Error> {
 499                 let (
 500                         PayerTlvStream { metadata: payer_metadata },
 501                         OfferTlvStream {
 502                                 chains, metadata, currency, amount: offer_amount, description,
 503                                 features: offer_features, absolute_expiry, paths, issuer, quantity_max, node_id,
 504                         },
 505                         InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
 506                 ) = tlv_stream;
 507
 508                 let payer = match payer_metadata {
 509                         None => return Err(SemanticError::MissingPayerMetadata),
 510                         Some(metadata) => PayerContents(metadata),
 511                 };
 512
 513                 if metadata.is_some() {
 514                         return Err(SemanticError::UnexpectedMetadata);
 515                 }
 516
 517                 if chains.is_some() {
 518                         return Err(SemanticError::UnexpectedChain);
 519                 }
 520
 521                 if currency.is_some() || offer_amount.is_some() {
 522                         return Err(SemanticError::UnexpectedAmount);
 523                 }
 524
 525                 let description = match description {
 526                         None => return Err(SemanticError::MissingDescription),
 527                         Some(description) => description,
 528                 };
 529
 530                 if offer_features.is_some() {
 531                         return Err(SemanticError::UnexpectedFeatures);
 532                 }
 533
 534                 let absolute_expiry = absolute_expiry.map(Duration::from_secs);
 535
 536                 if quantity_max.is_some() {
 537                         return Err(SemanticError::UnexpectedQuantity);
 538                 }
 539
 540                 if node_id.is_some() {
 541                         return Err(SemanticError::UnexpectedSigningPubkey);
 542                 }
 543
 544                 let amount_msats = match amount {
 545                         None => return Err(SemanticError::MissingAmount),
 546                         Some(amount_msats) if amount_msats > MAX_VALUE_MSAT => {
 547                                 return Err(SemanticError::InvalidAmount);
 548                         },
 549                         Some(amount_msats) => amount_msats,
 550                 };
 551
 552                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
 553
 554                 let payer_id = match payer_id {
 555                         None => return Err(SemanticError::MissingPayerId),
 556                         Some(payer_id) => payer_id,
 557                 };
 558
 559                 Ok(RefundContents {
 560                         payer, description, absolute_expiry, issuer, paths, chain, amount_msats, features,
 561                         quantity, payer_id, payer_note,
 562                 })
 563         }
 564 }
 565
 566 impl core::fmt::Display for Refund {
 567         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 568                 self.fmt_bech32_str(f)
 569         }
 570 }
 571
 572 #[cfg(test)]
 573 mod tests {
 574         use super::{Refund, RefundBuilder, RefundTlvStreamRef};
 575
 576         use bitcoin::blockdata::constants::ChainHash;
 577         use bitcoin::network::constants::Network;
 578         use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
 579         use core::convert::TryFrom;
 580         use core::time::Duration;
 581         use crate::ln::features::{InvoiceRequestFeatures, OfferFeatures};
 582         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 583         use crate::offers::invoice_request::InvoiceRequestTlvStreamRef;
 584         use crate::offers::offer::OfferTlvStreamRef;
 585         use crate::offers::parse::{ParseError, SemanticError};
 586         use crate::offers::payer::PayerTlvStreamRef;
 587         use crate::onion_message::{BlindedHop, BlindedPath};
 588         use crate::util::ser::{BigSize, Writeable};
 589         use crate::util::string::PrintableString;
 590
 591         fn payer_pubkey() -> PublicKey {
 592                 let secp_ctx = Secp256k1::new();
 593                 KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap()).public_key()
 594         }
 595
 596         fn pubkey(byte: u8) -> PublicKey {
 597                 let secp_ctx = Secp256k1::new();
 598                 PublicKey::from_secret_key(&secp_ctx, &privkey(byte))
 599         }
 600
 601         fn privkey(byte: u8) -> SecretKey {
 602                 SecretKey::from_slice(&[byte; 32]).unwrap()
 603         }
 604
 605         trait ToBytes {
 606                 fn to_bytes(&self) -> Vec<u8>;
 607         }
 608
 609         impl<'a> ToBytes for RefundTlvStreamRef<'a> {
 610                 fn to_bytes(&self) -> Vec<u8> {
 611                         let mut buffer = Vec::new();
 612                         self.write(&mut buffer).unwrap();
 613                         buffer
 614                 }
 615         }
 616
 617         #[test]
 618         fn builds_refund_with_defaults() {
 619                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 620                         .build().unwrap();
 621
 622                 let mut buffer = Vec::new();
 623                 refund.write(&mut buffer).unwrap();
 624
 625                 assert_eq!(refund.bytes, buffer.as_slice());
 626                 assert_eq!(refund.metadata(), &[1; 32]);
 627                 assert_eq!(refund.description(), PrintableString("foo"));
 628                 assert_eq!(refund.absolute_expiry(), None);
 629                 #[cfg(feature = "std")]
 630                 assert!(!refund.is_expired());
 631                 assert_eq!(refund.paths(), &[]);
 632                 assert_eq!(refund.issuer(), None);
 633                 assert_eq!(refund.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
 634                 assert_eq!(refund.amount_msats(), 1000);
 635                 assert_eq!(refund.features(), &InvoiceRequestFeatures::empty());
 636                 assert_eq!(refund.payer_id(), payer_pubkey());
 637                 assert_eq!(refund.payer_note(), None);
 638
 639                 assert_eq!(
 640                         refund.as_tlv_stream(),
 641                         (
 642                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
 643                                 OfferTlvStreamRef {
 644                                         chains: None,
 645                                         metadata: None,
 646                                         currency: None,
 647                                         amount: None,
 648                                         description: Some(&String::from("foo")),
 649                                         features: None,
 650                                         absolute_expiry: None,
 651                                         paths: None,
 652                                         issuer: None,
 653                                         quantity_max: None,
 654                                         node_id: None,
 655                                 },
 656                                 InvoiceRequestTlvStreamRef {
 657                                         chain: None,
 658                                         amount: Some(1000),
 659                                         features: None,
 660                                         quantity: None,
 661                                         payer_id: Some(&payer_pubkey()),
 662                                         payer_note: None,
 663                                 },
 664                         ),
 665                 );
 666
 667                 if let Err(e) = Refund::try_from(buffer) {
 668                         panic!("error parsing refund: {:?}", e);
 669                 }
 670         }
 671
 672         #[test]
 673         fn fails_building_refund_with_invalid_amount() {
 674                 match RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), MAX_VALUE_MSAT + 1) {
 675                         Ok(_) => panic!("expected error"),
 676                         Err(e) => assert_eq!(e, SemanticError::InvalidAmount),
 677                 }
 678         }
 679
 680         #[test]
 681         fn builds_refund_with_absolute_expiry() {
 682                 let future_expiry = Duration::from_secs(u64::max_value());
 683                 let past_expiry = Duration::from_secs(0);
 684
 685                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 686                         .absolute_expiry(future_expiry)
 687                         .build()
 688                         .unwrap();
 689                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 690                 #[cfg(feature = "std")]
 691                 assert!(!refund.is_expired());
 692                 assert_eq!(refund.absolute_expiry(), Some(future_expiry));
 693                 assert_eq!(tlv_stream.absolute_expiry, Some(future_expiry.as_secs()));
 694
 695                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 696                         .absolute_expiry(future_expiry)
 697                         .absolute_expiry(past_expiry)
 698                         .build()
 699                         .unwrap();
 700                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 701                 #[cfg(feature = "std")]
 702                 assert!(refund.is_expired());
 703                 assert_eq!(refund.absolute_expiry(), Some(past_expiry));
 704                 assert_eq!(tlv_stream.absolute_expiry, Some(past_expiry.as_secs()));
 705         }
 706
 707         #[test]
 708         fn builds_refund_with_paths() {
 709                 let paths = vec![
 710                         BlindedPath {
 711                                 introduction_node_id: pubkey(40),
 712                                 blinding_point: pubkey(41),
 713                                 blinded_hops: vec![
 714                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
 715                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
 716                                 ],
 717                         },
 718                         BlindedPath {
 719                                 introduction_node_id: pubkey(40),
 720                                 blinding_point: pubkey(41),
 721                                 blinded_hops: vec![
 722                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
 723                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
 724                                 ],
 725                         },
 726                 ];
 727
 728                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 729                         .path(paths[0].clone())
 730                         .path(paths[1].clone())
 731                         .build()
 732                         .unwrap();
 733                 let (_, offer_tlv_stream, invoice_request_tlv_stream) = refund.as_tlv_stream();
 734                 assert_eq!(refund.paths(), paths.as_slice());
 735                 assert_eq!(refund.payer_id(), pubkey(42));
 736                 assert_ne!(pubkey(42), pubkey(44));
 737                 assert_eq!(offer_tlv_stream.paths, Some(&paths));
 738                 assert_eq!(invoice_request_tlv_stream.payer_id, Some(&pubkey(42)));
 739         }
 740
 741         #[test]
 742         fn builds_refund_with_issuer() {
 743                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 744                         .issuer("bar".into())
 745                         .build()
 746                         .unwrap();
 747                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 748                 assert_eq!(refund.issuer(), Some(PrintableString("bar")));
 749                 assert_eq!(tlv_stream.issuer, Some(&String::from("bar")));
 750
 751                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 752                         .issuer("bar".into())
 753                         .issuer("baz".into())
 754                         .build()
 755                         .unwrap();
 756                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 757                 assert_eq!(refund.issuer(), Some(PrintableString("baz")));
 758                 assert_eq!(tlv_stream.issuer, Some(&String::from("baz")));
 759         }
 760
 761         #[test]
 762         fn builds_refund_with_chain() {
 763                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
 764                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
 765
 766                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 767                         .chain(Network::Bitcoin)
 768                         .build().unwrap();
 769                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 770                 assert_eq!(refund.chain(), mainnet);
 771                 assert_eq!(tlv_stream.chain, None);
 772
 773                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 774                         .chain(Network::Testnet)
 775                         .build().unwrap();
 776                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 777                 assert_eq!(refund.chain(), testnet);
 778                 assert_eq!(tlv_stream.chain, Some(&testnet));
 779
 780                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 781                         .chain(Network::Regtest)
 782                         .chain(Network::Testnet)
 783                         .build().unwrap();
 784                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 785                 assert_eq!(refund.chain(), testnet);
 786                 assert_eq!(tlv_stream.chain, Some(&testnet));
 787         }
 788
 789         #[test]
 790         fn builds_refund_with_quantity() {
 791                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 792                         .quantity(10)
 793                         .build().unwrap();
 794                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 795                 assert_eq!(refund.quantity(), Some(10));
 796                 assert_eq!(tlv_stream.quantity, Some(10));
 797
 798                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 799                         .quantity(10)
 800                         .quantity(1)
 801                         .build().unwrap();
 802                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 803                 assert_eq!(refund.quantity(), Some(1));
 804                 assert_eq!(tlv_stream.quantity, Some(1));
 805         }
 806
 807         #[test]
 808         fn builds_refund_with_payer_note() {
 809                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 810                         .payer_note("bar".into())
 811                         .build().unwrap();
 812                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 813                 assert_eq!(refund.payer_note(), Some(PrintableString("bar")));
 814                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
 815
 816                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 817                         .payer_note("bar".into())
 818                         .payer_note("baz".into())
 819                         .build().unwrap();
 820                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 821                 assert_eq!(refund.payer_note(), Some(PrintableString("baz")));
 822                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
 823         }
 824
 825         #[test]
 826         fn parses_refund_with_metadata() {
 827                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 828                         .build().unwrap();
 829                 if let Err(e) = refund.to_string().parse::<Refund>() {
 830                         panic!("error parsing refund: {:?}", e);
 831                 }
 832
 833                 let mut tlv_stream = refund.as_tlv_stream();
 834                 tlv_stream.0.metadata = None;
 835
 836                 match Refund::try_from(tlv_stream.to_bytes()) {
 837                         Ok(_) => panic!("expected error"),
 838                         Err(e) => {
 839                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPayerMetadata));
 840                         },
 841                 }
 842         }
 843
 844         #[test]
 845         fn parses_refund_with_description() {
 846                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 847                         .build().unwrap();
 848                 if let Err(e) = refund.to_string().parse::<Refund>() {
 849                         panic!("error parsing refund: {:?}", e);
 850                 }
 851
 852                 let mut tlv_stream = refund.as_tlv_stream();
 853                 tlv_stream.1.description = None;
 854
 855                 match Refund::try_from(tlv_stream.to_bytes()) {
 856                         Ok(_) => panic!("expected error"),
 857                         Err(e) => {
 858                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingDescription));
 859                         },
 860                 }
 861         }
 862
 863         #[test]
 864         fn parses_refund_with_amount() {
 865                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 866                         .build().unwrap();
 867                 if let Err(e) = refund.to_string().parse::<Refund>() {
 868                         panic!("error parsing refund: {:?}", e);
 869                 }
 870
 871                 let mut tlv_stream = refund.as_tlv_stream();
 872                 tlv_stream.2.amount = None;
 873
 874                 match Refund::try_from(tlv_stream.to_bytes()) {
 875                         Ok(_) => panic!("expected error"),
 876                         Err(e) => {
 877                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingAmount));
 878                         },
 879                 }
 880
 881                 let mut tlv_stream = refund.as_tlv_stream();
 882                 tlv_stream.2.amount = Some(MAX_VALUE_MSAT + 1);
 883
 884                 match Refund::try_from(tlv_stream.to_bytes()) {
 885                         Ok(_) => panic!("expected error"),
 886                         Err(e) => {
 887                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::InvalidAmount));
 888                         },
 889                 }
 890         }
 891
 892         #[test]
 893         fn parses_refund_with_payer_id() {
 894                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 895                         .build().unwrap();
 896                 if let Err(e) = refund.to_string().parse::<Refund>() {
 897                         panic!("error parsing refund: {:?}", e);
 898                 }
 899
 900                 let mut tlv_stream = refund.as_tlv_stream();
 901                 tlv_stream.2.payer_id = None;
 902
 903                 match Refund::try_from(tlv_stream.to_bytes()) {
 904                         Ok(_) => panic!("expected error"),
 905                         Err(e) => {
 906                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPayerId));
 907                         },
 908                 }
 909         }
 910
 911         #[test]
 912         fn parses_refund_with_optional_fields() {
 913                 let past_expiry = Duration::from_secs(0);
 914                 let paths = vec![
 915                         BlindedPath {
 916                                 introduction_node_id: pubkey(40),
 917                                 blinding_point: pubkey(41),
 918                                 blinded_hops: vec![
 919                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
 920                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
 921                                 ],
 922                         },
 923                         BlindedPath {
 924                                 introduction_node_id: pubkey(40),
 925                                 blinding_point: pubkey(41),
 926                                 blinded_hops: vec![
 927                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
 928                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
 929                                 ],
 930                         },
 931                 ];
 932
 933                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 934                         .absolute_expiry(past_expiry)
 935                         .issuer("bar".into())
 936                         .path(paths[0].clone())
 937                         .path(paths[1].clone())
 938                         .chain(Network::Testnet)
 939                         .features_unchecked(InvoiceRequestFeatures::unknown())
 940                         .quantity(10)
 941                         .payer_note("baz".into())
 942                         .build()
 943                         .unwrap();
 944                 match refund.to_string().parse::<Refund>() {
 945                         Ok(refund) => {
 946                                 assert_eq!(refund.absolute_expiry(), Some(past_expiry));
 947                                 #[cfg(feature = "std")]
 948                                 assert!(refund.is_expired());
 949                                 assert_eq!(refund.paths(), &paths[..]);
 950                                 assert_eq!(refund.issuer(), Some(PrintableString("bar")));
 951                                 assert_eq!(refund.chain(), ChainHash::using_genesis_block(Network::Testnet));
 952                                 assert_eq!(refund.features(), &InvoiceRequestFeatures::unknown());
 953                                 assert_eq!(refund.quantity(), Some(10));
 954                                 assert_eq!(refund.payer_note(), Some(PrintableString("baz")));
 955                         },
 956                         Err(e) => panic!("error parsing refund: {:?}", e),
 957                 }
 958         }
 959
 960         #[test]
 961         fn fails_parsing_refund_with_unexpected_fields() {
 962                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 963                         .build().unwrap();
 964                 if let Err(e) = refund.to_string().parse::<Refund>() {
 965                         panic!("error parsing refund: {:?}", e);
 966                 }
 967
 968                 let metadata = vec![42; 32];
 969                 let mut tlv_stream = refund.as_tlv_stream();
 970                 tlv_stream.1.metadata = Some(&metadata);
 971
 972                 match Refund::try_from(tlv_stream.to_bytes()) {
 973                         Ok(_) => panic!("expected error"),
 974                         Err(e) => {
 975                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedMetadata));
 976                         },
 977                 }
 978
 979                 let chains = vec![ChainHash::using_genesis_block(Network::Testnet)];
 980                 let mut tlv_stream = refund.as_tlv_stream();
 981                 tlv_stream.1.chains = Some(&chains);
 982
 983                 match Refund::try_from(tlv_stream.to_bytes()) {
 984                         Ok(_) => panic!("expected error"),
 985                         Err(e) => {
 986                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedChain));
 987                         },
 988                 }
 989
 990                 let mut tlv_stream = refund.as_tlv_stream();
 991                 tlv_stream.1.currency = Some(&b"USD");
 992                 tlv_stream.1.amount = Some(1000);
 993
 994                 match Refund::try_from(tlv_stream.to_bytes()) {
 995                         Ok(_) => panic!("expected error"),
 996                         Err(e) => {
 997                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedAmount));
 998                         },
 999                 }
1000
1001                 let features = OfferFeatures::unknown();
1002                 let mut tlv_stream = refund.as_tlv_stream();
1003                 tlv_stream.1.features = Some(&features);
1004
1005                 match Refund::try_from(tlv_stream.to_bytes()) {
1006                         Ok(_) => panic!("expected error"),
1007                         Err(e) => {
1008                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedFeatures));
1009                         },
1010                 }
1011
1012                 let mut tlv_stream = refund.as_tlv_stream();
1013                 tlv_stream.1.quantity_max = Some(10);
1014
1015                 match Refund::try_from(tlv_stream.to_bytes()) {
1016                         Ok(_) => panic!("expected error"),
1017                         Err(e) => {
1018                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedQuantity));
1019                         },
1020                 }
1021
1022                 let node_id = payer_pubkey();
1023                 let mut tlv_stream = refund.as_tlv_stream();
1024                 tlv_stream.1.node_id = Some(&node_id);
1025
1026                 match Refund::try_from(tlv_stream.to_bytes()) {
1027                         Ok(_) => panic!("expected error"),
1028                         Err(e) => {
1029                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedSigningPubkey));
1030                         },
1031                 }
1032         }
1033
1034         #[test]
1035         fn fails_parsing_refund_with_extra_tlv_records() {
1036                 let secp_ctx = Secp256k1::new();
1037                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1038                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], keys.public_key(), 1000).unwrap()
1039                         .build().unwrap();
1040
1041                 let mut encoded_refund = Vec::new();
1042                 refund.write(&mut encoded_refund).unwrap();
1043                 BigSize(1002).write(&mut encoded_refund).unwrap();
1044                 BigSize(32).write(&mut encoded_refund).unwrap();
1045                 [42u8; 32].write(&mut encoded_refund).unwrap();
1046
1047                 match Refund::try_from(encoded_refund) {
1048                         Ok(_) => panic!("expected error"),
1049                         Err(e) => assert_eq!(e, ParseError::Decode(DecodeError::InvalidValue)),
1050                 }
1051         }
1052 }