_ 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)]
 220 #[cfg_attr(test, derive(PartialEq))]
 221 pub struct Refund {
 222         pub(super) bytes: Vec<u8>,
 223         pub(super) contents: RefundContents,
 224 }
 225
 226 /// The contents of a [`Refund`], which may be shared with an [`Invoice`].
 227 ///
 228 /// [`Invoice`]: crate::offers::invoice::Invoice
 229 #[derive(Clone, Debug)]
 230 #[cfg_attr(test, derive(PartialEq))]
 231 pub(super) struct RefundContents {
 232         payer: PayerContents,
 233         // offer fields
 234         description: String,
 235         absolute_expiry: Option<Duration>,
 236         issuer: Option<String>,
 237         paths: Option<Vec<BlindedPath>>,
 238         // invoice_request fields
 239         chain: Option<ChainHash>,
 240         amount_msats: u64,
 241         features: InvoiceRequestFeatures,
 242         quantity: Option<u64>,
 243         payer_id: PublicKey,
 244         payer_note: Option<String>,
 245 }
 246
 247 impl Refund {
 248         /// A complete description of the purpose of the refund. Intended to be displayed to the user
 249         /// but with the caveat that it has not been verified in any way.
 250         pub fn description(&self) -> PrintableString {
 251                 PrintableString(&self.contents.description)
 252         }
 253
 254         /// Duration since the Unix epoch when an invoice should no longer be sent.
 255         ///
 256         /// If `None`, the refund does not expire.
 257         pub fn absolute_expiry(&self) -> Option<Duration> {
 258                 self.contents.absolute_expiry
 259         }
 260
 261         /// Whether the refund has expired.
 262         #[cfg(feature = "std")]
 263         pub fn is_expired(&self) -> bool {
 264                 self.contents.is_expired()
 265         }
 266
 267         /// The issuer of the refund, possibly beginning with `user@domain` or `domain`. Intended to be
 268         /// displayed to the user but with the caveat that it has not been verified in any way.
 269         pub fn issuer(&self) -> Option<PrintableString> {
 270                 self.contents.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 271         }
 272
 273         /// Paths to the sender originating from publicly reachable nodes. Blinded paths provide sender
 274         /// privacy by obfuscating its node id.
 275         pub fn paths(&self) -> &[BlindedPath] {
 276                 self.contents.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 277         }
 278
 279         /// An unpredictable series of bytes, typically containing information about the derivation of
 280         /// [`payer_id`].
 281         ///
 282         /// [`payer_id`]: Self::payer_id
 283         pub fn metadata(&self) -> &[u8] {
 284                 &self.contents.payer.0
 285         }
 286
 287         /// A chain that the refund is valid for.
 288         pub fn chain(&self) -> ChainHash {
 289                 self.contents.chain.unwrap_or_else(|| self.contents.implied_chain())
 290         }
 291
 292         /// The amount to refund in msats (i.e., the minimum lightning-payable unit for [`chain`]).
 293         ///
 294         /// [`chain`]: Self::chain
 295         pub fn amount_msats(&self) -> u64 {
 296                 self.contents.amount_msats
 297         }
 298
 299         /// Features pertaining to requesting an invoice.
 300         pub fn features(&self) -> &InvoiceRequestFeatures {
 301                 &self.contents.features
 302         }
 303
 304         /// The quantity of an item that refund is for.
 305         pub fn quantity(&self) -> Option<u64> {
 306                 self.contents.quantity
 307         }
 308
 309         /// A public node id to send to in the case where there are no [`paths`]. Otherwise, a possibly
 310         /// transient pubkey.
 311         ///
 312         /// [`paths`]: Self::paths
 313         pub fn payer_id(&self) -> PublicKey {
 314                 self.contents.payer_id
 315         }
 316
 317         /// Payer provided note to include in the invoice.
 318         pub fn payer_note(&self) -> Option<PrintableString> {
 319                 self.contents.payer_note.as_ref().map(|payer_note| PrintableString(payer_note.as_str()))
 320         }
 321
 322         /// Creates an [`Invoice`] for the refund with the given required fields and using the
 323         /// [`Duration`] since [`std::time::SystemTime::UNIX_EPOCH`] as the creation time.
 324         ///
 325         /// See [`Refund::respond_with_no_std`] for further details where the aforementioned creation
 326         /// time is used for the `created_at` parameter.
 327         ///
 328         /// [`Invoice`]: crate::offers::invoice::Invoice
 329         /// [`Duration`]: core::time::Duration
 330         #[cfg(feature = "std")]
 331         pub fn respond_with(
 332                 &self, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>, payment_hash: PaymentHash,
 333                 signing_pubkey: PublicKey,
 334         ) -> Result<InvoiceBuilder, SemanticError> {
 335                 let created_at = std::time::SystemTime::now()
 336                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 337                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 338
 339                 self.respond_with_no_std(payment_paths, payment_hash, signing_pubkey, created_at)
 340         }
 341
 342         /// Creates an [`Invoice`] for the refund with the given required fields.
 343         ///
 344         /// Unless [`InvoiceBuilder::relative_expiry`] is set, the invoice will expire two hours after
 345         /// `created_at`, which is used to set [`Invoice::created_at`]. Useful for `no-std` builds where
 346         /// [`std::time::SystemTime`] is not available.
 347         ///
 348         /// The caller is expected to remember the preimage of `payment_hash` in order to
 349         /// claim a payment for the invoice.
 350         ///
 351         /// The `signing_pubkey` is required to sign the invoice since refunds are not in response to an
 352         /// offer, which does have a `signing_pubkey`.
 353         ///
 354         /// The `payment_paths` parameter is useful for maintaining the payment recipient's privacy. It
 355         /// must contain one or more elements ordered from most-preferred to least-preferred, if there's
 356         /// a preference. Note, however, that any privacy is lost if a public node id is used for
 357         /// `signing_pubkey`.
 358         ///
 359         /// Errors if the request contains unknown required features.
 360         ///
 361         /// [`Invoice`]: crate::offers::invoice::Invoice
 362         /// [`Invoice::created_at`]: crate::offers::invoice::Invoice::created_at
 363         pub fn respond_with_no_std(
 364                 &self, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>, payment_hash: PaymentHash,
 365                 signing_pubkey: PublicKey, created_at: Duration
 366         ) -> Result<InvoiceBuilder, SemanticError> {
 367                 if self.features().requires_unknown_bits() {
 368                         return Err(SemanticError::UnknownRequiredFeatures);
 369                 }
 370
 371                 InvoiceBuilder::for_refund(self, payment_paths, created_at, payment_hash, signing_pubkey)
 372         }
 373
 374         #[cfg(test)]
 375         fn as_tlv_stream(&self) -> RefundTlvStreamRef {
 376                 self.contents.as_tlv_stream()
 377         }
 378 }
 379
 380 impl AsRef<[u8]> for Refund {
 381         fn as_ref(&self) -> &[u8] {
 382                 &self.bytes
 383         }
 384 }
 385
 386 impl RefundContents {
 387         #[cfg(feature = "std")]
 388         pub(super) fn is_expired(&self) -> bool {
 389                 match self.absolute_expiry {
 390                         Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() {
 391                                 Ok(elapsed) => elapsed > seconds_from_epoch,
 392                                 Err(_) => false,
 393                         },
 394                         None => false,
 395                 }
 396         }
 397
 398         pub(super) fn chain(&self) -> ChainHash {
 399                 self.chain.unwrap_or_else(|| self.implied_chain())
 400         }
 401
 402         pub fn implied_chain(&self) -> ChainHash {
 403                 ChainHash::using_genesis_block(Network::Bitcoin)
 404         }
 405
 406         pub(super) fn as_tlv_stream(&self) -> RefundTlvStreamRef {
 407                 let payer = PayerTlvStreamRef {
 408                         metadata: Some(&self.payer.0),
 409                 };
 410
 411                 let offer = OfferTlvStreamRef {
 412                         chains: None,
 413                         metadata: None,
 414                         currency: None,
 415                         amount: None,
 416                         description: Some(&self.description),
 417                         features: None,
 418                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 419                         paths: self.paths.as_ref(),
 420                         issuer: self.issuer.as_ref(),
 421                         quantity_max: None,
 422                         node_id: None,
 423                 };
 424
 425                 let features = {
 426                         if self.features == InvoiceRequestFeatures::empty() { None }
 427                         else { Some(&self.features) }
 428                 };
 429
 430                 let invoice_request = InvoiceRequestTlvStreamRef {
 431                         chain: self.chain.as_ref(),
 432                         amount: Some(self.amount_msats),
 433                         features,
 434                         quantity: self.quantity,
 435                         payer_id: Some(&self.payer_id),
 436                         payer_note: self.payer_note.as_ref(),
 437                 };
 438
 439                 (payer, offer, invoice_request)
 440         }
 441 }
 442
 443 impl Writeable for Refund {
 444         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 445                 WithoutLength(&self.bytes).write(writer)
 446         }
 447 }
 448
 449 impl Writeable for RefundContents {
 450         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 451                 self.as_tlv_stream().write(writer)
 452         }
 453 }
 454
 455 type RefundTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
 456
 457 type RefundTlvStreamRef<'a> = (
 458         PayerTlvStreamRef<'a>,
 459         OfferTlvStreamRef<'a>,
 460         InvoiceRequestTlvStreamRef<'a>,
 461 );
 462
 463 impl SeekReadable for RefundTlvStream {
 464         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 465                 let payer = SeekReadable::read(r)?;
 466                 let offer = SeekReadable::read(r)?;
 467                 let invoice_request = SeekReadable::read(r)?;
 468
 469                 Ok((payer, offer, invoice_request))
 470         }
 471 }
 472
 473 impl Bech32Encode for Refund {
 474         const BECH32_HRP: &'static str = "lnr";
 475 }
 476
 477 impl FromStr for Refund {
 478         type Err = ParseError;
 479
 480         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 481                 Refund::from_bech32_str(s)
 482         }
 483 }
 484
 485 impl TryFrom<Vec<u8>> for Refund {
 486         type Error = ParseError;
 487
 488         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 489                 let refund = ParsedMessage::<RefundTlvStream>::try_from(bytes)?;
 490                 let ParsedMessage { bytes, tlv_stream } = refund;
 491                 let contents = RefundContents::try_from(tlv_stream)?;
 492
 493                 Ok(Refund { bytes, contents })
 494         }
 495 }
 496
 497 impl TryFrom<RefundTlvStream> for RefundContents {
 498         type Error = SemanticError;
 499
 500         fn try_from(tlv_stream: RefundTlvStream) -> Result<Self, Self::Error> {
 501                 let (
 502                         PayerTlvStream { metadata: payer_metadata },
 503                         OfferTlvStream {
 504                                 chains, metadata, currency, amount: offer_amount, description,
 505                                 features: offer_features, absolute_expiry, paths, issuer, quantity_max, node_id,
 506                         },
 507                         InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
 508                 ) = tlv_stream;
 509
 510                 let payer = match payer_metadata {
 511                         None => return Err(SemanticError::MissingPayerMetadata),
 512                         Some(metadata) => PayerContents(metadata),
 513                 };
 514
 515                 if metadata.is_some() {
 516                         return Err(SemanticError::UnexpectedMetadata);
 517                 }
 518
 519                 if chains.is_some() {
 520                         return Err(SemanticError::UnexpectedChain);
 521                 }
 522
 523                 if currency.is_some() || offer_amount.is_some() {
 524                         return Err(SemanticError::UnexpectedAmount);
 525                 }
 526
 527                 let description = match description {
 528                         None => return Err(SemanticError::MissingDescription),
 529                         Some(description) => description,
 530                 };
 531
 532                 if offer_features.is_some() {
 533                         return Err(SemanticError::UnexpectedFeatures);
 534                 }
 535
 536                 let absolute_expiry = absolute_expiry.map(Duration::from_secs);
 537
 538                 if quantity_max.is_some() {
 539                         return Err(SemanticError::UnexpectedQuantity);
 540                 }
 541
 542                 if node_id.is_some() {
 543                         return Err(SemanticError::UnexpectedSigningPubkey);
 544                 }
 545
 546                 let amount_msats = match amount {
 547                         None => return Err(SemanticError::MissingAmount),
 548                         Some(amount_msats) if amount_msats > MAX_VALUE_MSAT => {
 549                                 return Err(SemanticError::InvalidAmount);
 550                         },
 551                         Some(amount_msats) => amount_msats,
 552                 };
 553
 554                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
 555
 556                 let payer_id = match payer_id {
 557                         None => return Err(SemanticError::MissingPayerId),
 558                         Some(payer_id) => payer_id,
 559                 };
 560
 561                 Ok(RefundContents {
 562                         payer, description, absolute_expiry, issuer, paths, chain, amount_msats, features,
 563                         quantity, payer_id, payer_note,
 564                 })
 565         }
 566 }
 567
 568 impl core::fmt::Display for Refund {
 569         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 570                 self.fmt_bech32_str(f)
 571         }
 572 }
 573
 574 #[cfg(test)]
 575 mod tests {
 576         use super::{Refund, RefundBuilder, RefundTlvStreamRef};
 577
 578         use bitcoin::blockdata::constants::ChainHash;
 579         use bitcoin::network::constants::Network;
 580         use bitcoin::secp256k1::{KeyPair, Secp256k1, SecretKey};
 581         use core::convert::TryFrom;
 582         use core::time::Duration;
 583         use crate::ln::features::{InvoiceRequestFeatures, OfferFeatures};
 584         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 585         use crate::offers::invoice_request::InvoiceRequestTlvStreamRef;
 586         use crate::offers::offer::OfferTlvStreamRef;
 587         use crate::offers::parse::{ParseError, SemanticError};
 588         use crate::offers::payer::PayerTlvStreamRef;
 589         use crate::offers::test_utils::*;
 590         use crate::onion_message::{BlindedHop, BlindedPath};
 591         use crate::util::ser::{BigSize, Writeable};
 592         use crate::util::string::PrintableString;
 593
 594         trait ToBytes {
 595                 fn to_bytes(&self) -> Vec<u8>;
 596         }
 597
 598         impl<'a> ToBytes for RefundTlvStreamRef<'a> {
 599                 fn to_bytes(&self) -> Vec<u8> {
 600                         let mut buffer = Vec::new();
 601                         self.write(&mut buffer).unwrap();
 602                         buffer
 603                 }
 604         }
 605
 606         #[test]
 607         fn builds_refund_with_defaults() {
 608                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 609                         .build().unwrap();
 610
 611                 let mut buffer = Vec::new();
 612                 refund.write(&mut buffer).unwrap();
 613
 614                 assert_eq!(refund.bytes, buffer.as_slice());
 615                 assert_eq!(refund.metadata(), &[1; 32]);
 616                 assert_eq!(refund.description(), PrintableString("foo"));
 617                 assert_eq!(refund.absolute_expiry(), None);
 618                 #[cfg(feature = "std")]
 619                 assert!(!refund.is_expired());
 620                 assert_eq!(refund.paths(), &[]);
 621                 assert_eq!(refund.issuer(), None);
 622                 assert_eq!(refund.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
 623                 assert_eq!(refund.amount_msats(), 1000);
 624                 assert_eq!(refund.features(), &InvoiceRequestFeatures::empty());
 625                 assert_eq!(refund.payer_id(), payer_pubkey());
 626                 assert_eq!(refund.payer_note(), None);
 627
 628                 assert_eq!(
 629                         refund.as_tlv_stream(),
 630                         (
 631                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
 632                                 OfferTlvStreamRef {
 633                                         chains: None,
 634                                         metadata: None,
 635                                         currency: None,
 636                                         amount: None,
 637                                         description: Some(&String::from("foo")),
 638                                         features: None,
 639                                         absolute_expiry: None,
 640                                         paths: None,
 641                                         issuer: None,
 642                                         quantity_max: None,
 643                                         node_id: None,
 644                                 },
 645                                 InvoiceRequestTlvStreamRef {
 646                                         chain: None,
 647                                         amount: Some(1000),
 648                                         features: None,
 649                                         quantity: None,
 650                                         payer_id: Some(&payer_pubkey()),
 651                                         payer_note: None,
 652                                 },
 653                         ),
 654                 );
 655
 656                 if let Err(e) = Refund::try_from(buffer) {
 657                         panic!("error parsing refund: {:?}", e);
 658                 }
 659         }
 660
 661         #[test]
 662         fn fails_building_refund_with_invalid_amount() {
 663                 match RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), MAX_VALUE_MSAT + 1) {
 664                         Ok(_) => panic!("expected error"),
 665                         Err(e) => assert_eq!(e, SemanticError::InvalidAmount),
 666                 }
 667         }
 668
 669         #[test]
 670         fn builds_refund_with_absolute_expiry() {
 671                 let future_expiry = Duration::from_secs(u64::max_value());
 672                 let past_expiry = Duration::from_secs(0);
 673
 674                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 675                         .absolute_expiry(future_expiry)
 676                         .build()
 677                         .unwrap();
 678                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 679                 #[cfg(feature = "std")]
 680                 assert!(!refund.is_expired());
 681                 assert_eq!(refund.absolute_expiry(), Some(future_expiry));
 682                 assert_eq!(tlv_stream.absolute_expiry, Some(future_expiry.as_secs()));
 683
 684                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 685                         .absolute_expiry(future_expiry)
 686                         .absolute_expiry(past_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(past_expiry));
 693                 assert_eq!(tlv_stream.absolute_expiry, Some(past_expiry.as_secs()));
 694         }
 695
 696         #[test]
 697         fn builds_refund_with_paths() {
 698                 let paths = vec![
 699                         BlindedPath {
 700                                 introduction_node_id: pubkey(40),
 701                                 blinding_point: pubkey(41),
 702                                 blinded_hops: vec![
 703                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
 704                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
 705                                 ],
 706                         },
 707                         BlindedPath {
 708                                 introduction_node_id: pubkey(40),
 709                                 blinding_point: pubkey(41),
 710                                 blinded_hops: vec![
 711                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
 712                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
 713                                 ],
 714                         },
 715                 ];
 716
 717                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 718                         .path(paths[0].clone())
 719                         .path(paths[1].clone())
 720                         .build()
 721                         .unwrap();
 722                 let (_, offer_tlv_stream, invoice_request_tlv_stream) = refund.as_tlv_stream();
 723                 assert_eq!(refund.paths(), paths.as_slice());
 724                 assert_eq!(refund.payer_id(), pubkey(42));
 725                 assert_ne!(pubkey(42), pubkey(44));
 726                 assert_eq!(offer_tlv_stream.paths, Some(&paths));
 727                 assert_eq!(invoice_request_tlv_stream.payer_id, Some(&pubkey(42)));
 728         }
 729
 730         #[test]
 731         fn builds_refund_with_issuer() {
 732                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 733                         .issuer("bar".into())
 734                         .build()
 735                         .unwrap();
 736                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 737                 assert_eq!(refund.issuer(), Some(PrintableString("bar")));
 738                 assert_eq!(tlv_stream.issuer, Some(&String::from("bar")));
 739
 740                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 741                         .issuer("bar".into())
 742                         .issuer("baz".into())
 743                         .build()
 744                         .unwrap();
 745                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 746                 assert_eq!(refund.issuer(), Some(PrintableString("baz")));
 747                 assert_eq!(tlv_stream.issuer, Some(&String::from("baz")));
 748         }
 749
 750         #[test]
 751         fn builds_refund_with_chain() {
 752                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
 753                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
 754
 755                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 756                         .chain(Network::Bitcoin)
 757                         .build().unwrap();
 758                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 759                 assert_eq!(refund.chain(), mainnet);
 760                 assert_eq!(tlv_stream.chain, None);
 761
 762                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 763                         .chain(Network::Testnet)
 764                         .build().unwrap();
 765                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 766                 assert_eq!(refund.chain(), testnet);
 767                 assert_eq!(tlv_stream.chain, Some(&testnet));
 768
 769                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 770                         .chain(Network::Regtest)
 771                         .chain(Network::Testnet)
 772                         .build().unwrap();
 773                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 774                 assert_eq!(refund.chain(), testnet);
 775                 assert_eq!(tlv_stream.chain, Some(&testnet));
 776         }
 777
 778         #[test]
 779         fn builds_refund_with_quantity() {
 780                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 781                         .quantity(10)
 782                         .build().unwrap();
 783                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 784                 assert_eq!(refund.quantity(), Some(10));
 785                 assert_eq!(tlv_stream.quantity, Some(10));
 786
 787                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 788                         .quantity(10)
 789                         .quantity(1)
 790                         .build().unwrap();
 791                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 792                 assert_eq!(refund.quantity(), Some(1));
 793                 assert_eq!(tlv_stream.quantity, Some(1));
 794         }
 795
 796         #[test]
 797         fn builds_refund_with_payer_note() {
 798                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 799                         .payer_note("bar".into())
 800                         .build().unwrap();
 801                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 802                 assert_eq!(refund.payer_note(), Some(PrintableString("bar")));
 803                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
 804
 805                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 806                         .payer_note("bar".into())
 807                         .payer_note("baz".into())
 808                         .build().unwrap();
 809                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 810                 assert_eq!(refund.payer_note(), Some(PrintableString("baz")));
 811                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
 812         }
 813
 814         #[test]
 815         fn fails_responding_with_unknown_required_features() {
 816                 match RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 817                         .features_unchecked(InvoiceRequestFeatures::unknown())
 818                         .build().unwrap()
 819                         .respond_with_no_std(payment_paths(), payment_hash(), recipient_pubkey(), now())
 820                 {
 821                         Ok(_) => panic!("expected error"),
 822                         Err(e) => assert_eq!(e, SemanticError::UnknownRequiredFeatures),
 823                 }
 824         }
 825
 826         #[test]
 827         fn parses_refund_with_metadata() {
 828                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 829                         .build().unwrap();
 830                 if let Err(e) = refund.to_string().parse::<Refund>() {
 831                         panic!("error parsing refund: {:?}", e);
 832                 }
 833
 834                 let mut tlv_stream = refund.as_tlv_stream();
 835                 tlv_stream.0.metadata = None;
 836
 837                 match Refund::try_from(tlv_stream.to_bytes()) {
 838                         Ok(_) => panic!("expected error"),
 839                         Err(e) => {
 840                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPayerMetadata));
 841                         },
 842                 }
 843         }
 844
 845         #[test]
 846         fn parses_refund_with_description() {
 847                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 848                         .build().unwrap();
 849                 if let Err(e) = refund.to_string().parse::<Refund>() {
 850                         panic!("error parsing refund: {:?}", e);
 851                 }
 852
 853                 let mut tlv_stream = refund.as_tlv_stream();
 854                 tlv_stream.1.description = None;
 855
 856                 match Refund::try_from(tlv_stream.to_bytes()) {
 857                         Ok(_) => panic!("expected error"),
 858                         Err(e) => {
 859                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingDescription));
 860                         },
 861                 }
 862         }
 863
 864         #[test]
 865         fn parses_refund_with_amount() {
 866                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 867                         .build().unwrap();
 868                 if let Err(e) = refund.to_string().parse::<Refund>() {
 869                         panic!("error parsing refund: {:?}", e);
 870                 }
 871
 872                 let mut tlv_stream = refund.as_tlv_stream();
 873                 tlv_stream.2.amount = None;
 874
 875                 match Refund::try_from(tlv_stream.to_bytes()) {
 876                         Ok(_) => panic!("expected error"),
 877                         Err(e) => {
 878                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingAmount));
 879                         },
 880                 }
 881
 882                 let mut tlv_stream = refund.as_tlv_stream();
 883                 tlv_stream.2.amount = Some(MAX_VALUE_MSAT + 1);
 884
 885                 match Refund::try_from(tlv_stream.to_bytes()) {
 886                         Ok(_) => panic!("expected error"),
 887                         Err(e) => {
 888                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::InvalidAmount));
 889                         },
 890                 }
 891         }
 892
 893         #[test]
 894         fn parses_refund_with_payer_id() {
 895                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 896                         .build().unwrap();
 897                 if let Err(e) = refund.to_string().parse::<Refund>() {
 898                         panic!("error parsing refund: {:?}", e);
 899                 }
 900
 901                 let mut tlv_stream = refund.as_tlv_stream();
 902                 tlv_stream.2.payer_id = None;
 903
 904                 match Refund::try_from(tlv_stream.to_bytes()) {
 905                         Ok(_) => panic!("expected error"),
 906                         Err(e) => {
 907                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPayerId));
 908                         },
 909                 }
 910         }
 911
 912         #[test]
 913         fn parses_refund_with_optional_fields() {
 914                 let past_expiry = Duration::from_secs(0);
 915                 let paths = vec![
 916                         BlindedPath {
 917                                 introduction_node_id: pubkey(40),
 918                                 blinding_point: pubkey(41),
 919                                 blinded_hops: vec![
 920                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
 921                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
 922                                 ],
 923                         },
 924                         BlindedPath {
 925                                 introduction_node_id: pubkey(40),
 926                                 blinding_point: pubkey(41),
 927                                 blinded_hops: vec![
 928                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
 929                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
 930                                 ],
 931                         },
 932                 ];
 933
 934                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 935                         .absolute_expiry(past_expiry)
 936                         .issuer("bar".into())
 937                         .path(paths[0].clone())
 938                         .path(paths[1].clone())
 939                         .chain(Network::Testnet)
 940                         .features_unchecked(InvoiceRequestFeatures::unknown())
 941                         .quantity(10)
 942                         .payer_note("baz".into())
 943                         .build()
 944                         .unwrap();
 945                 match refund.to_string().parse::<Refund>() {
 946                         Ok(refund) => {
 947                                 assert_eq!(refund.absolute_expiry(), Some(past_expiry));
 948                                 #[cfg(feature = "std")]
 949                                 assert!(refund.is_expired());
 950                                 assert_eq!(refund.paths(), &paths[..]);
 951                                 assert_eq!(refund.issuer(), Some(PrintableString("bar")));
 952                                 assert_eq!(refund.chain(), ChainHash::using_genesis_block(Network::Testnet));
 953                                 assert_eq!(refund.features(), &InvoiceRequestFeatures::unknown());
 954                                 assert_eq!(refund.quantity(), Some(10));
 955                                 assert_eq!(refund.payer_note(), Some(PrintableString("baz")));
 956                         },
 957                         Err(e) => panic!("error parsing refund: {:?}", e),
 958                 }
 959         }
 960
 961         #[test]
 962         fn fails_parsing_refund_with_unexpected_fields() {
 963                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 964                         .build().unwrap();
 965                 if let Err(e) = refund.to_string().parse::<Refund>() {
 966                         panic!("error parsing refund: {:?}", e);
 967                 }
 968
 969                 let metadata = vec![42; 32];
 970                 let mut tlv_stream = refund.as_tlv_stream();
 971                 tlv_stream.1.metadata = Some(&metadata);
 972
 973                 match Refund::try_from(tlv_stream.to_bytes()) {
 974                         Ok(_) => panic!("expected error"),
 975                         Err(e) => {
 976                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedMetadata));
 977                         },
 978                 }
 979
 980                 let chains = vec![ChainHash::using_genesis_block(Network::Testnet)];
 981                 let mut tlv_stream = refund.as_tlv_stream();
 982                 tlv_stream.1.chains = Some(&chains);
 983
 984                 match Refund::try_from(tlv_stream.to_bytes()) {
 985                         Ok(_) => panic!("expected error"),
 986                         Err(e) => {
 987                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedChain));
 988                         },
 989                 }
 990
 991                 let mut tlv_stream = refund.as_tlv_stream();
 992                 tlv_stream.1.currency = Some(&b"USD");
 993                 tlv_stream.1.amount = Some(1000);
 994
 995                 match Refund::try_from(tlv_stream.to_bytes()) {
 996                         Ok(_) => panic!("expected error"),
 997                         Err(e) => {
 998                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedAmount));
 999                         },
1000                 }
1001
1002                 let features = OfferFeatures::unknown();
1003                 let mut tlv_stream = refund.as_tlv_stream();
1004                 tlv_stream.1.features = Some(&features);
1005
1006                 match Refund::try_from(tlv_stream.to_bytes()) {
1007                         Ok(_) => panic!("expected error"),
1008                         Err(e) => {
1009                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedFeatures));
1010                         },
1011                 }
1012
1013                 let mut tlv_stream = refund.as_tlv_stream();
1014                 tlv_stream.1.quantity_max = Some(10);
1015
1016                 match Refund::try_from(tlv_stream.to_bytes()) {
1017                         Ok(_) => panic!("expected error"),
1018                         Err(e) => {
1019                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedQuantity));
1020                         },
1021                 }
1022
1023                 let node_id = payer_pubkey();
1024                 let mut tlv_stream = refund.as_tlv_stream();
1025                 tlv_stream.1.node_id = Some(&node_id);
1026
1027                 match Refund::try_from(tlv_stream.to_bytes()) {
1028                         Ok(_) => panic!("expected error"),
1029                         Err(e) => {
1030                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedSigningPubkey));
1031                         },
1032                 }
1033         }
1034
1035         #[test]
1036         fn fails_parsing_refund_with_extra_tlv_records() {
1037                 let secp_ctx = Secp256k1::new();
1038                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1039                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], keys.public_key(), 1000).unwrap()
1040                         .build().unwrap();
1041
1042                 let mut encoded_refund = Vec::new();
1043                 refund.write(&mut encoded_refund).unwrap();
1044                 BigSize(1002).write(&mut encoded_refund).unwrap();
1045                 BigSize(32).write(&mut encoded_refund).unwrap();
1046                 [42u8; 32].write(&mut encoded_refund).unwrap();
1047
1048                 match Refund::try_from(encoded_refund) {
1049                         Ok(_) => panic!("expected error"),
1050                         Err(e) => assert_eq!(e, ParseError::Decode(DecodeError::InvalidValue)),
1051                 }
1052         }
1053 }