_ 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::offers::signer::Metadata;
  90 use crate::onion_message::BlindedPath;
  91 use crate::util::ser::{SeekReadable, WithoutLength, Writeable, Writer};
  92 use crate::util::string::PrintableString;
  93
  94 use crate::prelude::*;
  95
  96 #[cfg(feature = "std")]
  97 use std::time::SystemTime;
  98
  99 /// Builds a [`Refund`] for the "offer for money" flow.
 100 ///
 101 /// See [module-level documentation] for usage.
 102 ///
 103 /// [module-level documentation]: self
 104 pub struct RefundBuilder {
 105         refund: RefundContents,
 106 }
 107
 108 impl RefundBuilder {
 109         /// Creates a new builder for a refund using the [`Refund::payer_id`] for the public node id to
 110         /// send to if no [`Refund::paths`] are set. Otherwise, it may be a transient pubkey.
 111         ///
 112         /// Additionally, sets the required [`Refund::description`], [`Refund::metadata`], and
 113         /// [`Refund::amount_msats`].
 114         pub fn new(
 115                 description: String, metadata: Vec<u8>, payer_id: PublicKey, amount_msats: u64
 116         ) -> Result<Self, SemanticError> {
 117                 if amount_msats > MAX_VALUE_MSAT {
 118                         return Err(SemanticError::InvalidAmount);
 119                 }
 120
 121                 let metadata = Metadata::Bytes(metadata);
 122                 let refund = RefundContents {
 123                         payer: PayerContents(metadata), description, absolute_expiry: None, issuer: None,
 124                         paths: None, chain: None, amount_msats, features: InvoiceRequestFeatures::empty(),
 125                         quantity: None, payer_id, payer_note: None,
 126                 };
 127
 128                 Ok(RefundBuilder { refund })
 129         }
 130
 131         /// Sets the [`Refund::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
 132         /// already passed is valid and can be checked for using [`Refund::is_expired`].
 133         ///
 134         /// Successive calls to this method will override the previous setting.
 135         pub fn absolute_expiry(mut self, absolute_expiry: Duration) -> Self {
 136                 self.refund.absolute_expiry = Some(absolute_expiry);
 137                 self
 138         }
 139
 140         /// Sets the [`Refund::issuer`].
 141         ///
 142         /// Successive calls to this method will override the previous setting.
 143         pub fn issuer(mut self, issuer: String) -> Self {
 144                 self.refund.issuer = Some(issuer);
 145                 self
 146         }
 147
 148         /// Adds a blinded path to [`Refund::paths`]. Must include at least one path if only connected
 149         /// by private channels or if [`Refund::payer_id`] is not a public node id.
 150         ///
 151         /// Successive calls to this method will add another blinded path. Caller is responsible for not
 152         /// adding duplicate paths.
 153         pub fn path(mut self, path: BlindedPath) -> Self {
 154                 self.refund.paths.get_or_insert_with(Vec::new).push(path);
 155                 self
 156         }
 157
 158         /// Sets the [`Refund::chain`] of the given [`Network`] for paying an invoice. If not
 159         /// called, [`Network::Bitcoin`] is assumed.
 160         ///
 161         /// Successive calls to this method will override the previous setting.
 162         pub fn chain(mut self, network: Network) -> Self {
 163                 self.refund.chain = Some(ChainHash::using_genesis_block(network));
 164                 self
 165         }
 166
 167         /// Sets [`Refund::quantity`] of items. This is purely for informational purposes. It is useful
 168         /// when the refund pertains to an [`Invoice`] that paid for more than one item from an
 169         /// [`Offer`] as specified by [`InvoiceRequest::quantity`].
 170         ///
 171         /// Successive calls to this method will override the previous setting.
 172         ///
 173         /// [`Invoice`]: crate::offers::invoice::Invoice
 174         /// [`InvoiceRequest::quantity`]: crate::offers::invoice_request::InvoiceRequest::quantity
 175         /// [`Offer`]: crate::offers::offer::Offer
 176         pub fn quantity(mut self, quantity: u64) -> Self {
 177                 self.refund.quantity = Some(quantity);
 178                 self
 179         }
 180
 181         /// Sets the [`Refund::payer_note`].
 182         ///
 183         /// Successive calls to this method will override the previous setting.
 184         pub fn payer_note(mut self, payer_note: String) -> Self {
 185                 self.refund.payer_note = Some(payer_note);
 186                 self
 187         }
 188
 189         /// Builds a [`Refund`] after checking for valid semantics.
 190         pub fn build(mut self) -> Result<Refund, SemanticError> {
 191                 if self.refund.chain() == self.refund.implied_chain() {
 192                         self.refund.chain = None;
 193                 }
 194
 195                 let mut bytes = Vec::new();
 196                 self.refund.write(&mut bytes).unwrap();
 197
 198                 Ok(Refund {
 199                         bytes,
 200                         contents: self.refund,
 201                 })
 202         }
 203 }
 204
 205 #[cfg(test)]
 206 impl RefundBuilder {
 207         fn features_unchecked(mut self, features: InvoiceRequestFeatures) -> Self {
 208                 self.refund.features = features;
 209                 self
 210         }
 211 }
 212
 213 /// A `Refund` is a request to send an [`Invoice`] without a preceding [`Offer`].
 214 ///
 215 /// Typically, after an invoice is paid, the recipient may publish a refund allowing the sender to
 216 /// recoup their funds. A refund may be used more generally as an "offer for money", such as with a
 217 /// bitcoin ATM.
 218 ///
 219 /// [`Invoice`]: crate::offers::invoice::Invoice
 220 /// [`Offer`]: crate::offers::offer::Offer
 221 #[derive(Clone, Debug)]
 222 #[cfg_attr(test, derive(PartialEq))]
 223 pub struct Refund {
 224         pub(super) bytes: Vec<u8>,
 225         pub(super) contents: RefundContents,
 226 }
 227
 228 /// The contents of a [`Refund`], which may be shared with an [`Invoice`].
 229 ///
 230 /// [`Invoice`]: crate::offers::invoice::Invoice
 231 #[derive(Clone, Debug)]
 232 #[cfg_attr(test, derive(PartialEq))]
 233 pub(super) struct RefundContents {
 234         payer: PayerContents,
 235         // offer fields
 236         description: String,
 237         absolute_expiry: Option<Duration>,
 238         issuer: Option<String>,
 239         paths: Option<Vec<BlindedPath>>,
 240         // invoice_request fields
 241         chain: Option<ChainHash>,
 242         amount_msats: u64,
 243         features: InvoiceRequestFeatures,
 244         quantity: Option<u64>,
 245         payer_id: PublicKey,
 246         payer_note: Option<String>,
 247 }
 248
 249 impl Refund {
 250         /// A complete description of the purpose of the refund. Intended to be displayed to the user
 251         /// but with the caveat that it has not been verified in any way.
 252         pub fn description(&self) -> PrintableString {
 253                 PrintableString(&self.contents.description)
 254         }
 255
 256         /// Duration since the Unix epoch when an invoice should no longer be sent.
 257         ///
 258         /// If `None`, the refund does not expire.
 259         pub fn absolute_expiry(&self) -> Option<Duration> {
 260                 self.contents.absolute_expiry
 261         }
 262
 263         /// Whether the refund has expired.
 264         #[cfg(feature = "std")]
 265         pub fn is_expired(&self) -> bool {
 266                 self.contents.is_expired()
 267         }
 268
 269         /// The issuer of the refund, possibly beginning with `user@domain` or `domain`. Intended to be
 270         /// displayed to the user but with the caveat that it has not been verified in any way.
 271         pub fn issuer(&self) -> Option<PrintableString> {
 272                 self.contents.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
 273         }
 274
 275         /// Paths to the sender originating from publicly reachable nodes. Blinded paths provide sender
 276         /// privacy by obfuscating its node id.
 277         pub fn paths(&self) -> &[BlindedPath] {
 278                 self.contents.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
 279         }
 280
 281         /// An unpredictable series of bytes, typically containing information about the derivation of
 282         /// [`payer_id`].
 283         ///
 284         /// [`payer_id`]: Self::payer_id
 285         pub fn metadata(&self) -> &[u8] {
 286                 &self.contents.payer.0.as_bytes().unwrap()[..]
 287         }
 288
 289         /// A chain that the refund is valid for.
 290         pub fn chain(&self) -> ChainHash {
 291                 self.contents.chain.unwrap_or_else(|| self.contents.implied_chain())
 292         }
 293
 294         /// The amount to refund in msats (i.e., the minimum lightning-payable unit for [`chain`]).
 295         ///
 296         /// [`chain`]: Self::chain
 297         pub fn amount_msats(&self) -> u64 {
 298                 self.contents.amount_msats
 299         }
 300
 301         /// Features pertaining to requesting an invoice.
 302         pub fn features(&self) -> &InvoiceRequestFeatures {
 303                 &self.contents.features
 304         }
 305
 306         /// The quantity of an item that refund is for.
 307         pub fn quantity(&self) -> Option<u64> {
 308                 self.contents.quantity
 309         }
 310
 311         /// A public node id to send to in the case where there are no [`paths`]. Otherwise, a possibly
 312         /// transient pubkey.
 313         ///
 314         /// [`paths`]: Self::paths
 315         pub fn payer_id(&self) -> PublicKey {
 316                 self.contents.payer_id
 317         }
 318
 319         /// Payer provided note to include in the invoice.
 320         pub fn payer_note(&self) -> Option<PrintableString> {
 321                 self.contents.payer_note.as_ref().map(|payer_note| PrintableString(payer_note.as_str()))
 322         }
 323
 324         /// Creates an [`Invoice`] for the refund with the given required fields and using the
 325         /// [`Duration`] since [`std::time::SystemTime::UNIX_EPOCH`] as the creation time.
 326         ///
 327         /// See [`Refund::respond_with_no_std`] for further details where the aforementioned creation
 328         /// time is used for the `created_at` parameter.
 329         ///
 330         /// [`Invoice`]: crate::offers::invoice::Invoice
 331         /// [`Duration`]: core::time::Duration
 332         #[cfg(feature = "std")]
 333         pub fn respond_with(
 334                 &self, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>, payment_hash: PaymentHash,
 335                 signing_pubkey: PublicKey,
 336         ) -> Result<InvoiceBuilder, SemanticError> {
 337                 let created_at = std::time::SystemTime::now()
 338                         .duration_since(std::time::SystemTime::UNIX_EPOCH)
 339                         .expect("SystemTime::now() should come after SystemTime::UNIX_EPOCH");
 340
 341                 self.respond_with_no_std(payment_paths, payment_hash, signing_pubkey, created_at)
 342         }
 343
 344         /// Creates an [`Invoice`] for the refund with the given required fields.
 345         ///
 346         /// Unless [`InvoiceBuilder::relative_expiry`] is set, the invoice will expire two hours after
 347         /// `created_at`, which is used to set [`Invoice::created_at`]. Useful for `no-std` builds where
 348         /// [`std::time::SystemTime`] is not available.
 349         ///
 350         /// The caller is expected to remember the preimage of `payment_hash` in order to
 351         /// claim a payment for the invoice.
 352         ///
 353         /// The `signing_pubkey` is required to sign the invoice since refunds are not in response to an
 354         /// offer, which does have a `signing_pubkey`.
 355         ///
 356         /// The `payment_paths` parameter is useful for maintaining the payment recipient's privacy. It
 357         /// must contain one or more elements ordered from most-preferred to least-preferred, if there's
 358         /// a preference. Note, however, that any privacy is lost if a public node id is used for
 359         /// `signing_pubkey`.
 360         ///
 361         /// Errors if the request contains unknown required features.
 362         ///
 363         /// [`Invoice`]: crate::offers::invoice::Invoice
 364         /// [`Invoice::created_at`]: crate::offers::invoice::Invoice::created_at
 365         pub fn respond_with_no_std(
 366                 &self, payment_paths: Vec<(BlindedPath, BlindedPayInfo)>, payment_hash: PaymentHash,
 367                 signing_pubkey: PublicKey, created_at: Duration
 368         ) -> Result<InvoiceBuilder, SemanticError> {
 369                 if self.features().requires_unknown_bits() {
 370                         return Err(SemanticError::UnknownRequiredFeatures);
 371                 }
 372
 373                 InvoiceBuilder::for_refund(self, payment_paths, created_at, payment_hash, signing_pubkey)
 374         }
 375
 376         #[cfg(test)]
 377         fn as_tlv_stream(&self) -> RefundTlvStreamRef {
 378                 self.contents.as_tlv_stream()
 379         }
 380 }
 381
 382 impl AsRef<[u8]> for Refund {
 383         fn as_ref(&self) -> &[u8] {
 384                 &self.bytes
 385         }
 386 }
 387
 388 impl RefundContents {
 389         #[cfg(feature = "std")]
 390         pub(super) fn is_expired(&self) -> bool {
 391                 match self.absolute_expiry {
 392                         Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() {
 393                                 Ok(elapsed) => elapsed > seconds_from_epoch,
 394                                 Err(_) => false,
 395                         },
 396                         None => false,
 397                 }
 398         }
 399
 400         pub(super) fn chain(&self) -> ChainHash {
 401                 self.chain.unwrap_or_else(|| self.implied_chain())
 402         }
 403
 404         pub fn implied_chain(&self) -> ChainHash {
 405                 ChainHash::using_genesis_block(Network::Bitcoin)
 406         }
 407
 408         pub(super) fn as_tlv_stream(&self) -> RefundTlvStreamRef {
 409                 let payer = PayerTlvStreamRef {
 410                         metadata: self.payer.0.as_bytes(),
 411                 };
 412
 413                 let offer = OfferTlvStreamRef {
 414                         chains: None,
 415                         metadata: None,
 416                         currency: None,
 417                         amount: None,
 418                         description: Some(&self.description),
 419                         features: None,
 420                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
 421                         paths: self.paths.as_ref(),
 422                         issuer: self.issuer.as_ref(),
 423                         quantity_max: None,
 424                         node_id: None,
 425                 };
 426
 427                 let features = {
 428                         if self.features == InvoiceRequestFeatures::empty() { None }
 429                         else { Some(&self.features) }
 430                 };
 431
 432                 let invoice_request = InvoiceRequestTlvStreamRef {
 433                         chain: self.chain.as_ref(),
 434                         amount: Some(self.amount_msats),
 435                         features,
 436                         quantity: self.quantity,
 437                         payer_id: Some(&self.payer_id),
 438                         payer_note: self.payer_note.as_ref(),
 439                 };
 440
 441                 (payer, offer, invoice_request)
 442         }
 443 }
 444
 445 impl Writeable for Refund {
 446         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 447                 WithoutLength(&self.bytes).write(writer)
 448         }
 449 }
 450
 451 impl Writeable for RefundContents {
 452         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 453                 self.as_tlv_stream().write(writer)
 454         }
 455 }
 456
 457 type RefundTlvStream = (PayerTlvStream, OfferTlvStream, InvoiceRequestTlvStream);
 458
 459 type RefundTlvStreamRef<'a> = (
 460         PayerTlvStreamRef<'a>,
 461         OfferTlvStreamRef<'a>,
 462         InvoiceRequestTlvStreamRef<'a>,
 463 );
 464
 465 impl SeekReadable for RefundTlvStream {
 466         fn read<R: io::Read + io::Seek>(r: &mut R) -> Result<Self, DecodeError> {
 467                 let payer = SeekReadable::read(r)?;
 468                 let offer = SeekReadable::read(r)?;
 469                 let invoice_request = SeekReadable::read(r)?;
 470
 471                 Ok((payer, offer, invoice_request))
 472         }
 473 }
 474
 475 impl Bech32Encode for Refund {
 476         const BECH32_HRP: &'static str = "lnr";
 477 }
 478
 479 impl FromStr for Refund {
 480         type Err = ParseError;
 481
 482         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
 483                 Refund::from_bech32_str(s)
 484         }
 485 }
 486
 487 impl TryFrom<Vec<u8>> for Refund {
 488         type Error = ParseError;
 489
 490         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
 491                 let refund = ParsedMessage::<RefundTlvStream>::try_from(bytes)?;
 492                 let ParsedMessage { bytes, tlv_stream } = refund;
 493                 let contents = RefundContents::try_from(tlv_stream)?;
 494
 495                 Ok(Refund { bytes, contents })
 496         }
 497 }
 498
 499 impl TryFrom<RefundTlvStream> for RefundContents {
 500         type Error = SemanticError;
 501
 502         fn try_from(tlv_stream: RefundTlvStream) -> Result<Self, Self::Error> {
 503                 let (
 504                         PayerTlvStream { metadata: payer_metadata },
 505                         OfferTlvStream {
 506                                 chains, metadata, currency, amount: offer_amount, description,
 507                                 features: offer_features, absolute_expiry, paths, issuer, quantity_max, node_id,
 508                         },
 509                         InvoiceRequestTlvStream { chain, amount, features, quantity, payer_id, payer_note },
 510                 ) = tlv_stream;
 511
 512                 let payer = match payer_metadata {
 513                         None => return Err(SemanticError::MissingPayerMetadata),
 514                         Some(metadata) => PayerContents(Metadata::Bytes(metadata)),
 515                 };
 516
 517                 if metadata.is_some() {
 518                         return Err(SemanticError::UnexpectedMetadata);
 519                 }
 520
 521                 if chains.is_some() {
 522                         return Err(SemanticError::UnexpectedChain);
 523                 }
 524
 525                 if currency.is_some() || offer_amount.is_some() {
 526                         return Err(SemanticError::UnexpectedAmount);
 527                 }
 528
 529                 let description = match description {
 530                         None => return Err(SemanticError::MissingDescription),
 531                         Some(description) => description,
 532                 };
 533
 534                 if offer_features.is_some() {
 535                         return Err(SemanticError::UnexpectedFeatures);
 536                 }
 537
 538                 let absolute_expiry = absolute_expiry.map(Duration::from_secs);
 539
 540                 if quantity_max.is_some() {
 541                         return Err(SemanticError::UnexpectedQuantity);
 542                 }
 543
 544                 if node_id.is_some() {
 545                         return Err(SemanticError::UnexpectedSigningPubkey);
 546                 }
 547
 548                 let amount_msats = match amount {
 549                         None => return Err(SemanticError::MissingAmount),
 550                         Some(amount_msats) if amount_msats > MAX_VALUE_MSAT => {
 551                                 return Err(SemanticError::InvalidAmount);
 552                         },
 553                         Some(amount_msats) => amount_msats,
 554                 };
 555
 556                 let features = features.unwrap_or_else(InvoiceRequestFeatures::empty);
 557
 558                 let payer_id = match payer_id {
 559                         None => return Err(SemanticError::MissingPayerId),
 560                         Some(payer_id) => payer_id,
 561                 };
 562
 563                 Ok(RefundContents {
 564                         payer, description, absolute_expiry, issuer, paths, chain, amount_msats, features,
 565                         quantity, payer_id, payer_note,
 566                 })
 567         }
 568 }
 569
 570 impl core::fmt::Display for Refund {
 571         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 572                 self.fmt_bech32_str(f)
 573         }
 574 }
 575
 576 #[cfg(test)]
 577 mod tests {
 578         use super::{Refund, RefundBuilder, RefundTlvStreamRef};
 579
 580         use bitcoin::blockdata::constants::ChainHash;
 581         use bitcoin::network::constants::Network;
 582         use bitcoin::secp256k1::{KeyPair, Secp256k1, SecretKey};
 583         use core::convert::TryFrom;
 584         use core::time::Duration;
 585         use crate::ln::features::{InvoiceRequestFeatures, OfferFeatures};
 586         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
 587         use crate::offers::invoice_request::InvoiceRequestTlvStreamRef;
 588         use crate::offers::offer::OfferTlvStreamRef;
 589         use crate::offers::parse::{ParseError, SemanticError};
 590         use crate::offers::payer::PayerTlvStreamRef;
 591         use crate::offers::test_utils::*;
 592         use crate::onion_message::{BlindedHop, BlindedPath};
 593         use crate::util::ser::{BigSize, Writeable};
 594         use crate::util::string::PrintableString;
 595
 596         trait ToBytes {
 597                 fn to_bytes(&self) -> Vec<u8>;
 598         }
 599
 600         impl<'a> ToBytes for RefundTlvStreamRef<'a> {
 601                 fn to_bytes(&self) -> Vec<u8> {
 602                         let mut buffer = Vec::new();
 603                         self.write(&mut buffer).unwrap();
 604                         buffer
 605                 }
 606         }
 607
 608         #[test]
 609         fn builds_refund_with_defaults() {
 610                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 611                         .build().unwrap();
 612
 613                 let mut buffer = Vec::new();
 614                 refund.write(&mut buffer).unwrap();
 615
 616                 assert_eq!(refund.bytes, buffer.as_slice());
 617                 assert_eq!(refund.metadata(), &[1; 32]);
 618                 assert_eq!(refund.description(), PrintableString("foo"));
 619                 assert_eq!(refund.absolute_expiry(), None);
 620                 #[cfg(feature = "std")]
 621                 assert!(!refund.is_expired());
 622                 assert_eq!(refund.paths(), &[]);
 623                 assert_eq!(refund.issuer(), None);
 624                 assert_eq!(refund.chain(), ChainHash::using_genesis_block(Network::Bitcoin));
 625                 assert_eq!(refund.amount_msats(), 1000);
 626                 assert_eq!(refund.features(), &InvoiceRequestFeatures::empty());
 627                 assert_eq!(refund.payer_id(), payer_pubkey());
 628                 assert_eq!(refund.payer_note(), None);
 629
 630                 assert_eq!(
 631                         refund.as_tlv_stream(),
 632                         (
 633                                 PayerTlvStreamRef { metadata: Some(&vec![1; 32]) },
 634                                 OfferTlvStreamRef {
 635                                         chains: None,
 636                                         metadata: None,
 637                                         currency: None,
 638                                         amount: None,
 639                                         description: Some(&String::from("foo")),
 640                                         features: None,
 641                                         absolute_expiry: None,
 642                                         paths: None,
 643                                         issuer: None,
 644                                         quantity_max: None,
 645                                         node_id: None,
 646                                 },
 647                                 InvoiceRequestTlvStreamRef {
 648                                         chain: None,
 649                                         amount: Some(1000),
 650                                         features: None,
 651                                         quantity: None,
 652                                         payer_id: Some(&payer_pubkey()),
 653                                         payer_note: None,
 654                                 },
 655                         ),
 656                 );
 657
 658                 if let Err(e) = Refund::try_from(buffer) {
 659                         panic!("error parsing refund: {:?}", e);
 660                 }
 661         }
 662
 663         #[test]
 664         fn fails_building_refund_with_invalid_amount() {
 665                 match RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), MAX_VALUE_MSAT + 1) {
 666                         Ok(_) => panic!("expected error"),
 667                         Err(e) => assert_eq!(e, SemanticError::InvalidAmount),
 668                 }
 669         }
 670
 671         #[test]
 672         fn builds_refund_with_absolute_expiry() {
 673                 let future_expiry = Duration::from_secs(u64::max_value());
 674                 let past_expiry = Duration::from_secs(0);
 675
 676                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 677                         .absolute_expiry(future_expiry)
 678                         .build()
 679                         .unwrap();
 680                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 681                 #[cfg(feature = "std")]
 682                 assert!(!refund.is_expired());
 683                 assert_eq!(refund.absolute_expiry(), Some(future_expiry));
 684                 assert_eq!(tlv_stream.absolute_expiry, Some(future_expiry.as_secs()));
 685
 686                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 687                         .absolute_expiry(future_expiry)
 688                         .absolute_expiry(past_expiry)
 689                         .build()
 690                         .unwrap();
 691                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 692                 #[cfg(feature = "std")]
 693                 assert!(refund.is_expired());
 694                 assert_eq!(refund.absolute_expiry(), Some(past_expiry));
 695                 assert_eq!(tlv_stream.absolute_expiry, Some(past_expiry.as_secs()));
 696         }
 697
 698         #[test]
 699         fn builds_refund_with_paths() {
 700                 let paths = vec![
 701                         BlindedPath {
 702                                 introduction_node_id: pubkey(40),
 703                                 blinding_point: pubkey(41),
 704                                 blinded_hops: vec![
 705                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
 706                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
 707                                 ],
 708                         },
 709                         BlindedPath {
 710                                 introduction_node_id: pubkey(40),
 711                                 blinding_point: pubkey(41),
 712                                 blinded_hops: vec![
 713                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
 714                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
 715                                 ],
 716                         },
 717                 ];
 718
 719                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 720                         .path(paths[0].clone())
 721                         .path(paths[1].clone())
 722                         .build()
 723                         .unwrap();
 724                 let (_, offer_tlv_stream, invoice_request_tlv_stream) = refund.as_tlv_stream();
 725                 assert_eq!(refund.paths(), paths.as_slice());
 726                 assert_eq!(refund.payer_id(), pubkey(42));
 727                 assert_ne!(pubkey(42), pubkey(44));
 728                 assert_eq!(offer_tlv_stream.paths, Some(&paths));
 729                 assert_eq!(invoice_request_tlv_stream.payer_id, Some(&pubkey(42)));
 730         }
 731
 732         #[test]
 733         fn builds_refund_with_issuer() {
 734                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 735                         .issuer("bar".into())
 736                         .build()
 737                         .unwrap();
 738                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 739                 assert_eq!(refund.issuer(), Some(PrintableString("bar")));
 740                 assert_eq!(tlv_stream.issuer, Some(&String::from("bar")));
 741
 742                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 743                         .issuer("bar".into())
 744                         .issuer("baz".into())
 745                         .build()
 746                         .unwrap();
 747                 let (_, tlv_stream, _) = refund.as_tlv_stream();
 748                 assert_eq!(refund.issuer(), Some(PrintableString("baz")));
 749                 assert_eq!(tlv_stream.issuer, Some(&String::from("baz")));
 750         }
 751
 752         #[test]
 753         fn builds_refund_with_chain() {
 754                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
 755                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
 756
 757                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 758                         .chain(Network::Bitcoin)
 759                         .build().unwrap();
 760                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 761                 assert_eq!(refund.chain(), mainnet);
 762                 assert_eq!(tlv_stream.chain, None);
 763
 764                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 765                         .chain(Network::Testnet)
 766                         .build().unwrap();
 767                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 768                 assert_eq!(refund.chain(), testnet);
 769                 assert_eq!(tlv_stream.chain, Some(&testnet));
 770
 771                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 772                         .chain(Network::Regtest)
 773                         .chain(Network::Testnet)
 774                         .build().unwrap();
 775                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 776                 assert_eq!(refund.chain(), testnet);
 777                 assert_eq!(tlv_stream.chain, Some(&testnet));
 778         }
 779
 780         #[test]
 781         fn builds_refund_with_quantity() {
 782                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 783                         .quantity(10)
 784                         .build().unwrap();
 785                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 786                 assert_eq!(refund.quantity(), Some(10));
 787                 assert_eq!(tlv_stream.quantity, Some(10));
 788
 789                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 790                         .quantity(10)
 791                         .quantity(1)
 792                         .build().unwrap();
 793                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 794                 assert_eq!(refund.quantity(), Some(1));
 795                 assert_eq!(tlv_stream.quantity, Some(1));
 796         }
 797
 798         #[test]
 799         fn builds_refund_with_payer_note() {
 800                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 801                         .payer_note("bar".into())
 802                         .build().unwrap();
 803                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 804                 assert_eq!(refund.payer_note(), Some(PrintableString("bar")));
 805                 assert_eq!(tlv_stream.payer_note, Some(&String::from("bar")));
 806
 807                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 808                         .payer_note("bar".into())
 809                         .payer_note("baz".into())
 810                         .build().unwrap();
 811                 let (_, _, tlv_stream) = refund.as_tlv_stream();
 812                 assert_eq!(refund.payer_note(), Some(PrintableString("baz")));
 813                 assert_eq!(tlv_stream.payer_note, Some(&String::from("baz")));
 814         }
 815
 816         #[test]
 817         fn fails_responding_with_unknown_required_features() {
 818                 match RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 819                         .features_unchecked(InvoiceRequestFeatures::unknown())
 820                         .build().unwrap()
 821                         .respond_with_no_std(payment_paths(), payment_hash(), recipient_pubkey(), now())
 822                 {
 823                         Ok(_) => panic!("expected error"),
 824                         Err(e) => assert_eq!(e, SemanticError::UnknownRequiredFeatures),
 825                 }
 826         }
 827
 828         #[test]
 829         fn parses_refund_with_metadata() {
 830                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 831                         .build().unwrap();
 832                 if let Err(e) = refund.to_string().parse::<Refund>() {
 833                         panic!("error parsing refund: {:?}", e);
 834                 }
 835
 836                 let mut tlv_stream = refund.as_tlv_stream();
 837                 tlv_stream.0.metadata = None;
 838
 839                 match Refund::try_from(tlv_stream.to_bytes()) {
 840                         Ok(_) => panic!("expected error"),
 841                         Err(e) => {
 842                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPayerMetadata));
 843                         },
 844                 }
 845         }
 846
 847         #[test]
 848         fn parses_refund_with_description() {
 849                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 850                         .build().unwrap();
 851                 if let Err(e) = refund.to_string().parse::<Refund>() {
 852                         panic!("error parsing refund: {:?}", e);
 853                 }
 854
 855                 let mut tlv_stream = refund.as_tlv_stream();
 856                 tlv_stream.1.description = None;
 857
 858                 match Refund::try_from(tlv_stream.to_bytes()) {
 859                         Ok(_) => panic!("expected error"),
 860                         Err(e) => {
 861                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingDescription));
 862                         },
 863                 }
 864         }
 865
 866         #[test]
 867         fn parses_refund_with_amount() {
 868                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 869                         .build().unwrap();
 870                 if let Err(e) = refund.to_string().parse::<Refund>() {
 871                         panic!("error parsing refund: {:?}", e);
 872                 }
 873
 874                 let mut tlv_stream = refund.as_tlv_stream();
 875                 tlv_stream.2.amount = None;
 876
 877                 match Refund::try_from(tlv_stream.to_bytes()) {
 878                         Ok(_) => panic!("expected error"),
 879                         Err(e) => {
 880                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingAmount));
 881                         },
 882                 }
 883
 884                 let mut tlv_stream = refund.as_tlv_stream();
 885                 tlv_stream.2.amount = Some(MAX_VALUE_MSAT + 1);
 886
 887                 match Refund::try_from(tlv_stream.to_bytes()) {
 888                         Ok(_) => panic!("expected error"),
 889                         Err(e) => {
 890                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::InvalidAmount));
 891                         },
 892                 }
 893         }
 894
 895         #[test]
 896         fn parses_refund_with_payer_id() {
 897                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 898                         .build().unwrap();
 899                 if let Err(e) = refund.to_string().parse::<Refund>() {
 900                         panic!("error parsing refund: {:?}", e);
 901                 }
 902
 903                 let mut tlv_stream = refund.as_tlv_stream();
 904                 tlv_stream.2.payer_id = None;
 905
 906                 match Refund::try_from(tlv_stream.to_bytes()) {
 907                         Ok(_) => panic!("expected error"),
 908                         Err(e) => {
 909                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingPayerId));
 910                         },
 911                 }
 912         }
 913
 914         #[test]
 915         fn parses_refund_with_optional_fields() {
 916                 let past_expiry = Duration::from_secs(0);
 917                 let paths = vec![
 918                         BlindedPath {
 919                                 introduction_node_id: pubkey(40),
 920                                 blinding_point: pubkey(41),
 921                                 blinded_hops: vec![
 922                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
 923                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
 924                                 ],
 925                         },
 926                         BlindedPath {
 927                                 introduction_node_id: pubkey(40),
 928                                 blinding_point: pubkey(41),
 929                                 blinded_hops: vec![
 930                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
 931                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
 932                                 ],
 933                         },
 934                 ];
 935
 936                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 937                         .absolute_expiry(past_expiry)
 938                         .issuer("bar".into())
 939                         .path(paths[0].clone())
 940                         .path(paths[1].clone())
 941                         .chain(Network::Testnet)
 942                         .features_unchecked(InvoiceRequestFeatures::unknown())
 943                         .quantity(10)
 944                         .payer_note("baz".into())
 945                         .build()
 946                         .unwrap();
 947                 match refund.to_string().parse::<Refund>() {
 948                         Ok(refund) => {
 949                                 assert_eq!(refund.absolute_expiry(), Some(past_expiry));
 950                                 #[cfg(feature = "std")]
 951                                 assert!(refund.is_expired());
 952                                 assert_eq!(refund.paths(), &paths[..]);
 953                                 assert_eq!(refund.issuer(), Some(PrintableString("bar")));
 954                                 assert_eq!(refund.chain(), ChainHash::using_genesis_block(Network::Testnet));
 955                                 assert_eq!(refund.features(), &InvoiceRequestFeatures::unknown());
 956                                 assert_eq!(refund.quantity(), Some(10));
 957                                 assert_eq!(refund.payer_note(), Some(PrintableString("baz")));
 958                         },
 959                         Err(e) => panic!("error parsing refund: {:?}", e),
 960                 }
 961         }
 962
 963         #[test]
 964         fn fails_parsing_refund_with_unexpected_fields() {
 965                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], payer_pubkey(), 1000).unwrap()
 966                         .build().unwrap();
 967                 if let Err(e) = refund.to_string().parse::<Refund>() {
 968                         panic!("error parsing refund: {:?}", e);
 969                 }
 970
 971                 let metadata = vec![42; 32];
 972                 let mut tlv_stream = refund.as_tlv_stream();
 973                 tlv_stream.1.metadata = Some(&metadata);
 974
 975                 match Refund::try_from(tlv_stream.to_bytes()) {
 976                         Ok(_) => panic!("expected error"),
 977                         Err(e) => {
 978                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedMetadata));
 979                         },
 980                 }
 981
 982                 let chains = vec![ChainHash::using_genesis_block(Network::Testnet)];
 983                 let mut tlv_stream = refund.as_tlv_stream();
 984                 tlv_stream.1.chains = Some(&chains);
 985
 986                 match Refund::try_from(tlv_stream.to_bytes()) {
 987                         Ok(_) => panic!("expected error"),
 988                         Err(e) => {
 989                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedChain));
 990                         },
 991                 }
 992
 993                 let mut tlv_stream = refund.as_tlv_stream();
 994                 tlv_stream.1.currency = Some(&b"USD");
 995                 tlv_stream.1.amount = Some(1000);
 996
 997                 match Refund::try_from(tlv_stream.to_bytes()) {
 998                         Ok(_) => panic!("expected error"),
 999                         Err(e) => {
1000                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedAmount));
1001                         },
1002                 }
1003
1004                 let features = OfferFeatures::unknown();
1005                 let mut tlv_stream = refund.as_tlv_stream();
1006                 tlv_stream.1.features = Some(&features);
1007
1008                 match Refund::try_from(tlv_stream.to_bytes()) {
1009                         Ok(_) => panic!("expected error"),
1010                         Err(e) => {
1011                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedFeatures));
1012                         },
1013                 }
1014
1015                 let mut tlv_stream = refund.as_tlv_stream();
1016                 tlv_stream.1.quantity_max = Some(10);
1017
1018                 match Refund::try_from(tlv_stream.to_bytes()) {
1019                         Ok(_) => panic!("expected error"),
1020                         Err(e) => {
1021                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedQuantity));
1022                         },
1023                 }
1024
1025                 let node_id = payer_pubkey();
1026                 let mut tlv_stream = refund.as_tlv_stream();
1027                 tlv_stream.1.node_id = Some(&node_id);
1028
1029                 match Refund::try_from(tlv_stream.to_bytes()) {
1030                         Ok(_) => panic!("expected error"),
1031                         Err(e) => {
1032                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::UnexpectedSigningPubkey));
1033                         },
1034                 }
1035         }
1036
1037         #[test]
1038         fn fails_parsing_refund_with_extra_tlv_records() {
1039                 let secp_ctx = Secp256k1::new();
1040                 let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
1041                 let refund = RefundBuilder::new("foo".into(), vec![1; 32], keys.public_key(), 1000).unwrap()
1042                         .build().unwrap();
1043
1044                 let mut encoded_refund = Vec::new();
1045                 refund.write(&mut encoded_refund).unwrap();
1046                 BigSize(1002).write(&mut encoded_refund).unwrap();
1047                 BigSize(32).write(&mut encoded_refund).unwrap();
1048                 [42u8; 32].write(&mut encoded_refund).unwrap();
1049
1050                 match Refund::try_from(encoded_refund) {
1051                         Ok(_) => panic!("expected error"),
1052                         Err(e) => assert_eq!(e, ParseError::Decode(DecodeError::InvalidValue)),
1053                 }
1054         }
1055 }