]> git.bitcoin.ninja Git - rust-lightning/blob - lightning/src/offers/offer.rs
Merge pull request #2226 from alecchendev/2023-04-persist-network-graph-on-rgs
[rust-lightning] / lightning / src / offers / offer.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 `offer` messages.
11 //!
12 //! An [`Offer`] represents an "offer to be paid." It is typically constructed by a merchant and
13 //! published as a QR code to be scanned by a customer. The customer uses the offer to request an
14 //! invoice from the merchant to be paid.
15 //!
16 //! ```
17 //! extern crate bitcoin;
18 //! extern crate core;
19 //! extern crate lightning;
20 //!
21 //! use core::convert::TryFrom;
22 //! use core::num::NonZeroU64;
23 //! use core::time::Duration;
24 //!
25 //! use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
26 //! use lightning::offers::offer::{Offer, OfferBuilder, Quantity};
27 //! use lightning::offers::parse::ParseError;
28 //! use lightning::util::ser::{Readable, Writeable};
29 //!
30 //! # use lightning::blinded_path::BlindedPath;
31 //! # #[cfg(feature = "std")]
32 //! # use std::time::SystemTime;
33 //! #
34 //! # fn create_blinded_path() -> BlindedPath { unimplemented!() }
35 //! # fn create_another_blinded_path() -> BlindedPath { unimplemented!() }
36 //! #
37 //! # #[cfg(feature = "std")]
38 //! # fn build() -> Result<(), ParseError> {
39 //! let secp_ctx = Secp256k1::new();
40 //! let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
41 //! let pubkey = PublicKey::from(keys);
42 //!
43 //! let expiration = SystemTime::now() + Duration::from_secs(24 * 60 * 60);
44 //! let offer = OfferBuilder::new("coffee, large".to_string(), pubkey)
45 //!     .amount_msats(20_000)
46 //!     .supported_quantity(Quantity::Unbounded)
47 //!     .absolute_expiry(expiration.duration_since(SystemTime::UNIX_EPOCH).unwrap())
48 //!     .issuer("Foo Bar".to_string())
49 //!     .path(create_blinded_path())
50 //!     .path(create_another_blinded_path())
51 //!     .build()?;
52 //!
53 //! // Encode as a bech32 string for use in a QR code.
54 //! let encoded_offer = offer.to_string();
55 //!
56 //! // Parse from a bech32 string after scanning from a QR code.
57 //! let offer = encoded_offer.parse::<Offer>()?;
58 //!
59 //! // Encode offer as raw bytes.
60 //! let mut bytes = Vec::new();
61 //! offer.write(&mut bytes).unwrap();
62 //!
63 //! // Decode raw bytes into an offer.
64 //! let offer = Offer::try_from(bytes)?;
65 //! # Ok(())
66 //! # }
67 //! ```
68
69 use bitcoin::blockdata::constants::ChainHash;
70 use bitcoin::network::constants::Network;
71 use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, self};
72 use core::convert::TryFrom;
73 use core::num::NonZeroU64;
74 use core::ops::Deref;
75 use core::str::FromStr;
76 use core::time::Duration;
77 use crate::sign::EntropySource;
78 use crate::io;
79 use crate::blinded_path::BlindedPath;
80 use crate::ln::features::OfferFeatures;
81 use crate::ln::inbound_payment::{ExpandedKey, IV_LEN, Nonce};
82 use crate::ln::msgs::MAX_VALUE_MSAT;
83 use crate::offers::invoice_request::{DerivedPayerId, ExplicitPayerId, InvoiceRequestBuilder};
84 use crate::offers::merkle::TlvStream;
85 use crate::offers::parse::{Bech32Encode, ParseError, ParsedMessage, SemanticError};
86 use crate::offers::signer::{Metadata, MetadataMaterial, self};
87 use crate::util::ser::{HighZeroBytesDroppedBigSize, WithoutLength, Writeable, Writer};
88 use crate::util::string::PrintableString;
89
90 use crate::prelude::*;
91
92 #[cfg(feature = "std")]
93 use std::time::SystemTime;
94
95 pub(super) const IV_BYTES: &[u8; IV_LEN] = b"LDK Offer ~~~~~~";
96
97 /// Builds an [`Offer`] for the "offer to be paid" flow.
98 ///
99 /// See [module-level documentation] for usage.
100 ///
101 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
102 ///
103 /// [module-level documentation]: self
104 pub struct OfferBuilder<'a, M: MetadataStrategy, T: secp256k1::Signing> {
105         offer: OfferContents,
106         metadata_strategy: core::marker::PhantomData<M>,
107         secp_ctx: Option<&'a Secp256k1<T>>,
108 }
109
110 /// Indicates how [`Offer::metadata`] may be set.
111 ///
112 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
113 pub trait MetadataStrategy {}
114
115 /// [`Offer::metadata`] may be explicitly set or left empty.
116 ///
117 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
118 pub struct ExplicitMetadata {}
119
120 /// [`Offer::metadata`] will be derived.
121 ///
122 /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
123 pub struct DerivedMetadata {}
124
125 impl MetadataStrategy for ExplicitMetadata {}
126 impl MetadataStrategy for DerivedMetadata {}
127
128 impl<'a> OfferBuilder<'a, ExplicitMetadata, secp256k1::SignOnly> {
129         /// Creates a new builder for an offer setting the [`Offer::description`] and using the
130         /// [`Offer::signing_pubkey`] for signing invoices. The associated secret key must be remembered
131         /// while the offer is valid.
132         ///
133         /// Use a different pubkey per offer to avoid correlating offers.
134         pub fn new(description: String, signing_pubkey: PublicKey) -> Self {
135                 OfferBuilder {
136                         offer: OfferContents {
137                                 chains: None, metadata: None, amount: None, description,
138                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
139                                 supported_quantity: Quantity::One, signing_pubkey,
140                         },
141                         metadata_strategy: core::marker::PhantomData,
142                         secp_ctx: None,
143                 }
144         }
145
146         /// Sets the [`Offer::metadata`] to the given bytes.
147         ///
148         /// Successive calls to this method will override the previous setting.
149         pub fn metadata(mut self, metadata: Vec<u8>) -> Result<Self, SemanticError> {
150                 self.offer.metadata = Some(Metadata::Bytes(metadata));
151                 Ok(self)
152         }
153 }
154
155 impl<'a, T: secp256k1::Signing> OfferBuilder<'a, DerivedMetadata, T> {
156         /// Similar to [`OfferBuilder::new`] except, if [`OfferBuilder::path`] is called, the signing
157         /// pubkey is derived from the given [`ExpandedKey`] and [`EntropySource`]. This provides
158         /// recipient privacy by using a different signing pubkey for each offer. Otherwise, the
159         /// provided `node_id` is used for the signing pubkey.
160         ///
161         /// Also, sets the metadata when [`OfferBuilder::build`] is called such that it can be used by
162         /// [`InvoiceRequest::verify`] to determine if the request was produced for the offer given an
163         /// [`ExpandedKey`].
164         ///
165         /// [`InvoiceRequest::verify`]: crate::offers::invoice_request::InvoiceRequest::verify
166         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
167         pub fn deriving_signing_pubkey<ES: Deref>(
168                 description: String, node_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES,
169                 secp_ctx: &'a Secp256k1<T>
170         ) -> Self where ES::Target: EntropySource {
171                 let nonce = Nonce::from_entropy_source(entropy_source);
172                 let derivation_material = MetadataMaterial::new(nonce, expanded_key, IV_BYTES);
173                 let metadata = Metadata::DerivedSigningPubkey(derivation_material);
174                 OfferBuilder {
175                         offer: OfferContents {
176                                 chains: None, metadata: Some(metadata), amount: None, description,
177                                 features: OfferFeatures::empty(), absolute_expiry: None, issuer: None, paths: None,
178                                 supported_quantity: Quantity::One, signing_pubkey: node_id,
179                         },
180                         metadata_strategy: core::marker::PhantomData,
181                         secp_ctx: Some(secp_ctx),
182                 }
183         }
184 }
185
186 impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
187         /// Adds the chain hash of the given [`Network`] to [`Offer::chains`]. If not called,
188         /// the chain hash of [`Network::Bitcoin`] is assumed to be the only one supported.
189         ///
190         /// See [`Offer::chains`] on how this relates to the payment currency.
191         ///
192         /// Successive calls to this method will add another chain hash.
193         pub fn chain(mut self, network: Network) -> Self {
194                 let chains = self.offer.chains.get_or_insert_with(Vec::new);
195                 let chain = ChainHash::using_genesis_block(network);
196                 if !chains.contains(&chain) {
197                         chains.push(chain);
198                 }
199
200                 self
201         }
202
203         /// Sets the [`Offer::amount`] as an [`Amount::Bitcoin`].
204         ///
205         /// Successive calls to this method will override the previous setting.
206         pub fn amount_msats(self, amount_msats: u64) -> Self {
207                 self.amount(Amount::Bitcoin { amount_msats })
208         }
209
210         /// Sets the [`Offer::amount`].
211         ///
212         /// Successive calls to this method will override the previous setting.
213         pub(super) fn amount(mut self, amount: Amount) -> Self {
214                 self.offer.amount = Some(amount);
215                 self
216         }
217
218         /// Sets the [`Offer::absolute_expiry`] as seconds since the Unix epoch. Any expiry that has
219         /// already passed is valid and can be checked for using [`Offer::is_expired`].
220         ///
221         /// Successive calls to this method will override the previous setting.
222         pub fn absolute_expiry(mut self, absolute_expiry: Duration) -> Self {
223                 self.offer.absolute_expiry = Some(absolute_expiry);
224                 self
225         }
226
227         /// Sets the [`Offer::issuer`].
228         ///
229         /// Successive calls to this method will override the previous setting.
230         pub fn issuer(mut self, issuer: String) -> Self {
231                 self.offer.issuer = Some(issuer);
232                 self
233         }
234
235         /// Adds a blinded path to [`Offer::paths`]. Must include at least one path if only connected by
236         /// private channels or if [`Offer::signing_pubkey`] is not a public node id.
237         ///
238         /// Successive calls to this method will add another blinded path. Caller is responsible for not
239         /// adding duplicate paths.
240         pub fn path(mut self, path: BlindedPath) -> Self {
241                 self.offer.paths.get_or_insert_with(Vec::new).push(path);
242                 self
243         }
244
245         /// Sets the quantity of items for [`Offer::supported_quantity`]. If not called, defaults to
246         /// [`Quantity::One`].
247         ///
248         /// Successive calls to this method will override the previous setting.
249         pub fn supported_quantity(mut self, quantity: Quantity) -> Self {
250                 self.offer.supported_quantity = quantity;
251                 self
252         }
253
254         /// Builds an [`Offer`] from the builder's settings.
255         pub fn build(mut self) -> Result<Offer, SemanticError> {
256                 match self.offer.amount {
257                         Some(Amount::Bitcoin { amount_msats }) => {
258                                 if amount_msats > MAX_VALUE_MSAT {
259                                         return Err(SemanticError::InvalidAmount);
260                                 }
261                         },
262                         Some(Amount::Currency { .. }) => return Err(SemanticError::UnsupportedCurrency),
263                         None => {},
264                 }
265
266                 if let Some(chains) = &self.offer.chains {
267                         if chains.len() == 1 && chains[0] == self.offer.implied_chain() {
268                                 self.offer.chains = None;
269                         }
270                 }
271
272                 Ok(self.build_without_checks())
273         }
274
275         fn build_without_checks(mut self) -> Offer {
276                 // Create the metadata for stateless verification of an InvoiceRequest.
277                 if let Some(mut metadata) = self.offer.metadata.take() {
278                         if metadata.has_derivation_material() {
279                                 if self.offer.paths.is_none() {
280                                         metadata = metadata.without_keys();
281                                 }
282
283                                 let mut tlv_stream = self.offer.as_tlv_stream();
284                                 debug_assert_eq!(tlv_stream.metadata, None);
285                                 tlv_stream.metadata = None;
286                                 if metadata.derives_keys() {
287                                         tlv_stream.node_id = None;
288                                 }
289
290                                 let (derived_metadata, keys) = metadata.derive_from(tlv_stream, self.secp_ctx);
291                                 metadata = derived_metadata;
292                                 if let Some(keys) = keys {
293                                         self.offer.signing_pubkey = keys.public_key();
294                                 }
295                         }
296
297                         self.offer.metadata = Some(metadata);
298                 }
299
300                 let mut bytes = Vec::new();
301                 self.offer.write(&mut bytes).unwrap();
302
303                 Offer { bytes, contents: self.offer }
304         }
305 }
306
307 #[cfg(test)]
308 impl<'a, M: MetadataStrategy, T: secp256k1::Signing> OfferBuilder<'a, M, T> {
309         fn features_unchecked(mut self, features: OfferFeatures) -> Self {
310                 self.offer.features = features;
311                 self
312         }
313
314         pub(super) fn build_unchecked(self) -> Offer {
315                 self.build_without_checks()
316         }
317 }
318
319 /// An `Offer` is a potentially long-lived proposal for payment of a good or service.
320 ///
321 /// An offer is a precursor to an [`InvoiceRequest`]. A merchant publishes an offer from which a
322 /// customer may request an [`Invoice`] for a specific quantity and using an amount sufficient to
323 /// cover that quantity (i.e., at least `quantity * amount`). See [`Offer::amount`].
324 ///
325 /// Offers may be denominated in currency other than bitcoin but are ultimately paid using the
326 /// latter.
327 ///
328 /// Through the use of [`BlindedPath`]s, offers provide recipient privacy.
329 ///
330 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
331 /// [`Invoice`]: crate::offers::invoice::Invoice
332 #[derive(Clone, Debug)]
333 #[cfg_attr(test, derive(PartialEq))]
334 pub struct Offer {
335         // The serialized offer. Needed when creating an `InvoiceRequest` if the offer contains unknown
336         // fields.
337         pub(super) bytes: Vec<u8>,
338         pub(super) contents: OfferContents,
339 }
340
341 /// The contents of an [`Offer`], which may be shared with an [`InvoiceRequest`] or an [`Invoice`].
342 ///
343 /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
344 /// [`Invoice`]: crate::offers::invoice::Invoice
345 #[derive(Clone, Debug)]
346 #[cfg_attr(test, derive(PartialEq))]
347 pub(super) struct OfferContents {
348         chains: Option<Vec<ChainHash>>,
349         metadata: Option<Metadata>,
350         amount: Option<Amount>,
351         description: String,
352         features: OfferFeatures,
353         absolute_expiry: Option<Duration>,
354         issuer: Option<String>,
355         paths: Option<Vec<BlindedPath>>,
356         supported_quantity: Quantity,
357         signing_pubkey: PublicKey,
358 }
359
360 impl Offer {
361         // TODO: Return a slice once ChainHash has constants.
362         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1283
363         // - https://github.com/rust-bitcoin/rust-bitcoin/pull/1286
364         /// The chains that may be used when paying a requested invoice (e.g., bitcoin mainnet).
365         /// Payments must be denominated in units of the minimal lightning-payable unit (e.g., msats)
366         /// for the selected chain.
367         pub fn chains(&self) -> Vec<ChainHash> {
368                 self.contents.chains()
369         }
370
371         pub(super) fn implied_chain(&self) -> ChainHash {
372                 self.contents.implied_chain()
373         }
374
375         /// Returns whether the given chain is supported by the offer.
376         pub fn supports_chain(&self, chain: ChainHash) -> bool {
377                 self.contents.supports_chain(chain)
378         }
379
380         // TODO: Link to corresponding method in `InvoiceRequest`.
381         /// Opaque bytes set by the originator. Useful for authentication and validating fields since it
382         /// is reflected in `invoice_request` messages along with all the other fields from the `offer`.
383         pub fn metadata(&self) -> Option<&Vec<u8>> {
384                 self.contents.metadata()
385         }
386
387         /// The minimum amount required for a successful payment of a single item.
388         pub fn amount(&self) -> Option<&Amount> {
389                 self.contents.amount()
390         }
391
392         /// A complete description of the purpose of the payment. Intended to be displayed to the user
393         /// but with the caveat that it has not been verified in any way.
394         pub fn description(&self) -> PrintableString {
395                 self.contents.description()
396         }
397
398         /// Features pertaining to the offer.
399         pub fn features(&self) -> &OfferFeatures {
400                 &self.contents.features
401         }
402
403         /// Duration since the Unix epoch when an invoice should no longer be requested.
404         ///
405         /// If `None`, the offer does not expire.
406         pub fn absolute_expiry(&self) -> Option<Duration> {
407                 self.contents.absolute_expiry
408         }
409
410         /// Whether the offer has expired.
411         #[cfg(feature = "std")]
412         pub fn is_expired(&self) -> bool {
413                 self.contents.is_expired()
414         }
415
416         /// The issuer of the offer, possibly beginning with `user@domain` or `domain`. Intended to be
417         /// displayed to the user but with the caveat that it has not been verified in any way.
418         pub fn issuer(&self) -> Option<PrintableString> {
419                 self.contents.issuer.as_ref().map(|issuer| PrintableString(issuer.as_str()))
420         }
421
422         /// Paths to the recipient originating from publicly reachable nodes. Blinded paths provide
423         /// recipient privacy by obfuscating its node id.
424         pub fn paths(&self) -> &[BlindedPath] {
425                 self.contents.paths.as_ref().map(|paths| paths.as_slice()).unwrap_or(&[])
426         }
427
428         /// The quantity of items supported.
429         pub fn supported_quantity(&self) -> Quantity {
430                 self.contents.supported_quantity()
431         }
432
433         /// Returns whether the given quantity is valid for the offer.
434         pub fn is_valid_quantity(&self, quantity: u64) -> bool {
435                 self.contents.is_valid_quantity(quantity)
436         }
437
438         /// Returns whether a quantity is expected in an [`InvoiceRequest`] for the offer.
439         ///
440         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
441         pub fn expects_quantity(&self) -> bool {
442                 self.contents.expects_quantity()
443         }
444
445         /// The public key used by the recipient to sign invoices.
446         pub fn signing_pubkey(&self) -> PublicKey {
447                 self.contents.signing_pubkey()
448         }
449
450         /// Similar to [`Offer::request_invoice`] except it:
451         /// - derives the [`InvoiceRequest::payer_id`] such that a different key can be used for each
452         ///   request, and
453         /// - sets the [`InvoiceRequest::metadata`] when [`InvoiceRequestBuilder::build`] is called such
454         ///   that it can be used by [`Invoice::verify`] to determine if the invoice was requested using
455         ///   a base [`ExpandedKey`] from which the payer id was derived.
456         ///
457         /// Useful to protect the sender's privacy.
458         ///
459         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
460         ///
461         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
462         /// [`InvoiceRequest::metadata`]: crate::offers::invoice_request::InvoiceRequest::metadata
463         /// [`Invoice::verify`]: crate::offers::invoice::Invoice::verify
464         /// [`ExpandedKey`]: crate::ln::inbound_payment::ExpandedKey
465         pub fn request_invoice_deriving_payer_id<'a, 'b, ES: Deref, T: secp256k1::Signing>(
466                 &'a self, expanded_key: &ExpandedKey, entropy_source: ES, secp_ctx: &'b Secp256k1<T>
467         ) -> Result<InvoiceRequestBuilder<'a, 'b, DerivedPayerId, T>, SemanticError>
468         where
469                 ES::Target: EntropySource,
470         {
471                 if self.features().requires_unknown_bits() {
472                         return Err(SemanticError::UnknownRequiredFeatures);
473                 }
474
475                 Ok(InvoiceRequestBuilder::deriving_payer_id(self, expanded_key, entropy_source, secp_ctx))
476         }
477
478         /// Similar to [`Offer::request_invoice_deriving_payer_id`] except uses `payer_id` for the
479         /// [`InvoiceRequest::payer_id`] instead of deriving a different key for each request.
480         ///
481         /// Useful for recurring payments using the same `payer_id` with different invoices.
482         ///
483         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
484         ///
485         /// [`InvoiceRequest::payer_id`]: crate::offers::invoice_request::InvoiceRequest::payer_id
486         pub fn request_invoice_deriving_metadata<ES: Deref>(
487                 &self, payer_id: PublicKey, expanded_key: &ExpandedKey, entropy_source: ES
488         ) -> Result<InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>, SemanticError>
489         where
490                 ES::Target: EntropySource,
491         {
492                 if self.features().requires_unknown_bits() {
493                         return Err(SemanticError::UnknownRequiredFeatures);
494                 }
495
496                 Ok(InvoiceRequestBuilder::deriving_metadata(self, payer_id, expanded_key, entropy_source))
497         }
498
499         /// Creates an [`InvoiceRequestBuilder`] for the offer with the given `metadata` and `payer_id`,
500         /// which will be reflected in the `Invoice` response.
501         ///
502         /// The `metadata` is useful for including information about the derivation of `payer_id` such
503         /// that invoice response handling can be stateless. Also serves as payer-provided entropy while
504         /// hashing in the signature calculation.
505         ///
506         /// This should not leak any information such as by using a simple BIP-32 derivation path.
507         /// Otherwise, payments may be correlated.
508         ///
509         /// Errors if the offer contains unknown required features.
510         ///
511         /// This is not exported to bindings users as builder patterns don't map outside of move semantics.
512         ///
513         /// [`InvoiceRequest`]: crate::offers::invoice_request::InvoiceRequest
514         pub fn request_invoice(
515                 &self, metadata: Vec<u8>, payer_id: PublicKey
516         ) -> Result<InvoiceRequestBuilder<ExplicitPayerId, secp256k1::SignOnly>, SemanticError> {
517                 if self.features().requires_unknown_bits() {
518                         return Err(SemanticError::UnknownRequiredFeatures);
519                 }
520
521                 Ok(InvoiceRequestBuilder::new(self, metadata, payer_id))
522         }
523
524         #[cfg(test)]
525         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
526                 self.contents.as_tlv_stream()
527         }
528 }
529
530 impl AsRef<[u8]> for Offer {
531         fn as_ref(&self) -> &[u8] {
532                 &self.bytes
533         }
534 }
535
536 impl OfferContents {
537         pub fn chains(&self) -> Vec<ChainHash> {
538                 self.chains.as_ref().cloned().unwrap_or_else(|| vec![self.implied_chain()])
539         }
540
541         pub fn implied_chain(&self) -> ChainHash {
542                 ChainHash::using_genesis_block(Network::Bitcoin)
543         }
544
545         pub fn supports_chain(&self, chain: ChainHash) -> bool {
546                 self.chains().contains(&chain)
547         }
548
549         pub fn metadata(&self) -> Option<&Vec<u8>> {
550                 self.metadata.as_ref().and_then(|metadata| metadata.as_bytes())
551         }
552
553         pub fn description(&self) -> PrintableString {
554                 PrintableString(&self.description)
555         }
556
557         #[cfg(feature = "std")]
558         pub(super) fn is_expired(&self) -> bool {
559                 match self.absolute_expiry {
560                         Some(seconds_from_epoch) => match SystemTime::UNIX_EPOCH.elapsed() {
561                                 Ok(elapsed) => elapsed > seconds_from_epoch,
562                                 Err(_) => false,
563                         },
564                         None => false,
565                 }
566         }
567
568         pub fn amount(&self) -> Option<&Amount> {
569                 self.amount.as_ref()
570         }
571
572         pub(super) fn check_amount_msats_for_quantity(
573                 &self, amount_msats: Option<u64>, quantity: Option<u64>
574         ) -> Result<(), SemanticError> {
575                 let offer_amount_msats = match self.amount {
576                         None => 0,
577                         Some(Amount::Bitcoin { amount_msats }) => amount_msats,
578                         Some(Amount::Currency { .. }) => return Err(SemanticError::UnsupportedCurrency),
579                 };
580
581                 if !self.expects_quantity() || quantity.is_some() {
582                         let expected_amount_msats = offer_amount_msats.checked_mul(quantity.unwrap_or(1))
583                                 .ok_or(SemanticError::InvalidAmount)?;
584                         let amount_msats = amount_msats.unwrap_or(expected_amount_msats);
585
586                         if amount_msats < expected_amount_msats {
587                                 return Err(SemanticError::InsufficientAmount);
588                         }
589
590                         if amount_msats > MAX_VALUE_MSAT {
591                                 return Err(SemanticError::InvalidAmount);
592                         }
593                 }
594
595                 Ok(())
596         }
597
598         pub fn supported_quantity(&self) -> Quantity {
599                 self.supported_quantity
600         }
601
602         pub(super) fn check_quantity(&self, quantity: Option<u64>) -> Result<(), SemanticError> {
603                 let expects_quantity = self.expects_quantity();
604                 match quantity {
605                         None if expects_quantity => Err(SemanticError::MissingQuantity),
606                         Some(_) if !expects_quantity => Err(SemanticError::UnexpectedQuantity),
607                         Some(quantity) if !self.is_valid_quantity(quantity) => {
608                                 Err(SemanticError::InvalidQuantity)
609                         },
610                         _ => Ok(()),
611                 }
612         }
613
614         fn is_valid_quantity(&self, quantity: u64) -> bool {
615                 match self.supported_quantity {
616                         Quantity::Bounded(n) => quantity <= n.get(),
617                         Quantity::Unbounded => quantity > 0,
618                         Quantity::One => quantity == 1,
619                 }
620         }
621
622         fn expects_quantity(&self) -> bool {
623                 match self.supported_quantity {
624                         Quantity::Bounded(_) => true,
625                         Quantity::Unbounded => true,
626                         Quantity::One => false,
627                 }
628         }
629
630         pub(super) fn signing_pubkey(&self) -> PublicKey {
631                 self.signing_pubkey
632         }
633
634         /// Verifies that the offer metadata was produced from the offer in the TLV stream.
635         pub(super) fn verify<T: secp256k1::Signing>(
636                 &self, bytes: &[u8], key: &ExpandedKey, secp_ctx: &Secp256k1<T>
637         ) -> Result<Option<KeyPair>, ()> {
638                 match self.metadata() {
639                         Some(metadata) => {
640                                 let tlv_stream = TlvStream::new(bytes).range(OFFER_TYPES).filter(|record| {
641                                         match record.r#type {
642                                                 OFFER_METADATA_TYPE => false,
643                                                 OFFER_NODE_ID_TYPE => !self.metadata.as_ref().unwrap().derives_keys(),
644                                                 _ => true,
645                                         }
646                                 });
647                                 signer::verify_metadata(
648                                         metadata, key, IV_BYTES, self.signing_pubkey(), tlv_stream, secp_ctx
649                                 )
650                         },
651                         None => Err(()),
652                 }
653         }
654
655         pub(super) fn as_tlv_stream(&self) -> OfferTlvStreamRef {
656                 let (currency, amount) = match &self.amount {
657                         None => (None, None),
658                         Some(Amount::Bitcoin { amount_msats }) => (None, Some(*amount_msats)),
659                         Some(Amount::Currency { iso4217_code, amount }) => (
660                                 Some(iso4217_code), Some(*amount)
661                         ),
662                 };
663
664                 let features = {
665                         if self.features == OfferFeatures::empty() { None } else { Some(&self.features) }
666                 };
667
668                 OfferTlvStreamRef {
669                         chains: self.chains.as_ref(),
670                         metadata: self.metadata(),
671                         currency,
672                         amount,
673                         description: Some(&self.description),
674                         features,
675                         absolute_expiry: self.absolute_expiry.map(|duration| duration.as_secs()),
676                         paths: self.paths.as_ref(),
677                         issuer: self.issuer.as_ref(),
678                         quantity_max: self.supported_quantity.to_tlv_record(),
679                         node_id: Some(&self.signing_pubkey),
680                 }
681         }
682 }
683
684 impl Writeable for Offer {
685         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
686                 WithoutLength(&self.bytes).write(writer)
687         }
688 }
689
690 impl Writeable for OfferContents {
691         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
692                 self.as_tlv_stream().write(writer)
693         }
694 }
695
696 /// The minimum amount required for an item in an [`Offer`], denominated in either bitcoin or
697 /// another currency.
698 #[derive(Clone, Debug, PartialEq)]
699 pub enum Amount {
700         /// An amount of bitcoin.
701         Bitcoin {
702                 /// The amount in millisatoshi.
703                 amount_msats: u64,
704         },
705         /// An amount of currency specified using ISO 4712.
706         Currency {
707                 /// The currency that the amount is denominated in.
708                 iso4217_code: CurrencyCode,
709                 /// The amount in the currency unit adjusted by the ISO 4712 exponent (e.g., USD cents).
710                 amount: u64,
711         },
712 }
713
714 /// An ISO 4712 three-letter currency code (e.g., USD).
715 pub type CurrencyCode = [u8; 3];
716
717 /// Quantity of items supported by an [`Offer`].
718 #[derive(Clone, Copy, Debug, PartialEq)]
719 pub enum Quantity {
720         /// Up to a specific number of items (inclusive). Use when more than one item can be requested
721         /// but is limited (e.g., because of per customer or inventory limits).
722         ///
723         /// May be used with `NonZeroU64::new(1)` but prefer to use [`Quantity::One`] if only one item
724         /// is supported.
725         Bounded(NonZeroU64),
726         /// One or more items. Use when more than one item can be requested without any limit.
727         Unbounded,
728         /// Only one item. Use when only a single item can be requested.
729         One,
730 }
731
732 impl Quantity {
733         fn to_tlv_record(&self) -> Option<u64> {
734                 match self {
735                         Quantity::Bounded(n) => Some(n.get()),
736                         Quantity::Unbounded => Some(0),
737                         Quantity::One => None,
738                 }
739         }
740 }
741
742 /// Valid type range for offer TLV records.
743 pub(super) const OFFER_TYPES: core::ops::Range<u64> = 1..80;
744
745 /// TLV record type for [`Offer::metadata`].
746 const OFFER_METADATA_TYPE: u64 = 4;
747
748 /// TLV record type for [`Offer::signing_pubkey`].
749 const OFFER_NODE_ID_TYPE: u64 = 22;
750
751 tlv_stream!(OfferTlvStream, OfferTlvStreamRef, OFFER_TYPES, {
752         (2, chains: (Vec<ChainHash>, WithoutLength)),
753         (OFFER_METADATA_TYPE, metadata: (Vec<u8>, WithoutLength)),
754         (6, currency: CurrencyCode),
755         (8, amount: (u64, HighZeroBytesDroppedBigSize)),
756         (10, description: (String, WithoutLength)),
757         (12, features: (OfferFeatures, WithoutLength)),
758         (14, absolute_expiry: (u64, HighZeroBytesDroppedBigSize)),
759         (16, paths: (Vec<BlindedPath>, WithoutLength)),
760         (18, issuer: (String, WithoutLength)),
761         (20, quantity_max: (u64, HighZeroBytesDroppedBigSize)),
762         (OFFER_NODE_ID_TYPE, node_id: PublicKey),
763 });
764
765 impl Bech32Encode for Offer {
766         const BECH32_HRP: &'static str = "lno";
767 }
768
769 impl FromStr for Offer {
770         type Err = ParseError;
771
772         fn from_str(s: &str) -> Result<Self, <Self as FromStr>::Err> {
773                 Self::from_bech32_str(s)
774         }
775 }
776
777 impl TryFrom<Vec<u8>> for Offer {
778         type Error = ParseError;
779
780         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
781                 let offer = ParsedMessage::<OfferTlvStream>::try_from(bytes)?;
782                 let ParsedMessage { bytes, tlv_stream } = offer;
783                 let contents = OfferContents::try_from(tlv_stream)?;
784                 Ok(Offer { bytes, contents })
785         }
786 }
787
788 impl TryFrom<OfferTlvStream> for OfferContents {
789         type Error = SemanticError;
790
791         fn try_from(tlv_stream: OfferTlvStream) -> Result<Self, Self::Error> {
792                 let OfferTlvStream {
793                         chains, metadata, currency, amount, description, features, absolute_expiry, paths,
794                         issuer, quantity_max, node_id,
795                 } = tlv_stream;
796
797                 let metadata = metadata.map(|metadata| Metadata::Bytes(metadata));
798
799                 let amount = match (currency, amount) {
800                         (None, None) => None,
801                         (None, Some(amount_msats)) if amount_msats > MAX_VALUE_MSAT => {
802                                 return Err(SemanticError::InvalidAmount);
803                         },
804                         (None, Some(amount_msats)) => Some(Amount::Bitcoin { amount_msats }),
805                         (Some(_), None) => return Err(SemanticError::MissingAmount),
806                         (Some(iso4217_code), Some(amount)) => Some(Amount::Currency { iso4217_code, amount }),
807                 };
808
809                 let description = match description {
810                         None => return Err(SemanticError::MissingDescription),
811                         Some(description) => description,
812                 };
813
814                 let features = features.unwrap_or_else(OfferFeatures::empty);
815
816                 let absolute_expiry = absolute_expiry
817                         .map(|seconds_from_epoch| Duration::from_secs(seconds_from_epoch));
818
819                 let supported_quantity = match quantity_max {
820                         None => Quantity::One,
821                         Some(0) => Quantity::Unbounded,
822                         Some(n) => Quantity::Bounded(NonZeroU64::new(n).unwrap()),
823                 };
824
825                 let signing_pubkey = match node_id {
826                         None => return Err(SemanticError::MissingSigningPubkey),
827                         Some(node_id) => node_id,
828                 };
829
830                 Ok(OfferContents {
831                         chains, metadata, amount, description, features, absolute_expiry, issuer, paths,
832                         supported_quantity, signing_pubkey,
833                 })
834         }
835 }
836
837 impl core::fmt::Display for Offer {
838         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
839                 self.fmt_bech32_str(f)
840         }
841 }
842
843 #[cfg(test)]
844 mod tests {
845         use super::{Amount, Offer, OfferBuilder, OfferTlvStreamRef, Quantity};
846
847         use bitcoin::blockdata::constants::ChainHash;
848         use bitcoin::network::constants::Network;
849         use bitcoin::secp256k1::Secp256k1;
850         use core::convert::TryFrom;
851         use core::num::NonZeroU64;
852         use core::time::Duration;
853         use crate::blinded_path::{BlindedHop, BlindedPath};
854         use crate::sign::KeyMaterial;
855         use crate::ln::features::OfferFeatures;
856         use crate::ln::inbound_payment::ExpandedKey;
857         use crate::ln::msgs::{DecodeError, MAX_VALUE_MSAT};
858         use crate::offers::parse::{ParseError, SemanticError};
859         use crate::offers::test_utils::*;
860         use crate::util::ser::{BigSize, Writeable};
861         use crate::util::string::PrintableString;
862
863         #[test]
864         fn builds_offer_with_defaults() {
865                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
866
867                 let mut buffer = Vec::new();
868                 offer.write(&mut buffer).unwrap();
869
870                 assert_eq!(offer.bytes, buffer.as_slice());
871                 assert_eq!(offer.chains(), vec![ChainHash::using_genesis_block(Network::Bitcoin)]);
872                 assert!(offer.supports_chain(ChainHash::using_genesis_block(Network::Bitcoin)));
873                 assert_eq!(offer.metadata(), None);
874                 assert_eq!(offer.amount(), None);
875                 assert_eq!(offer.description(), PrintableString("foo"));
876                 assert_eq!(offer.features(), &OfferFeatures::empty());
877                 assert_eq!(offer.absolute_expiry(), None);
878                 #[cfg(feature = "std")]
879                 assert!(!offer.is_expired());
880                 assert_eq!(offer.paths(), &[]);
881                 assert_eq!(offer.issuer(), None);
882                 assert_eq!(offer.supported_quantity(), Quantity::One);
883                 assert_eq!(offer.signing_pubkey(), pubkey(42));
884
885                 assert_eq!(
886                         offer.as_tlv_stream(),
887                         OfferTlvStreamRef {
888                                 chains: None,
889                                 metadata: None,
890                                 currency: None,
891                                 amount: None,
892                                 description: Some(&String::from("foo")),
893                                 features: None,
894                                 absolute_expiry: None,
895                                 paths: None,
896                                 issuer: None,
897                                 quantity_max: None,
898                                 node_id: Some(&pubkey(42)),
899                         },
900                 );
901
902                 if let Err(e) = Offer::try_from(buffer) {
903                         panic!("error parsing offer: {:?}", e);
904                 }
905         }
906
907         #[test]
908         fn builds_offer_with_chains() {
909                 let mainnet = ChainHash::using_genesis_block(Network::Bitcoin);
910                 let testnet = ChainHash::using_genesis_block(Network::Testnet);
911
912                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
913                         .chain(Network::Bitcoin)
914                         .build()
915                         .unwrap();
916                 assert!(offer.supports_chain(mainnet));
917                 assert_eq!(offer.chains(), vec![mainnet]);
918                 assert_eq!(offer.as_tlv_stream().chains, None);
919
920                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
921                         .chain(Network::Testnet)
922                         .build()
923                         .unwrap();
924                 assert!(offer.supports_chain(testnet));
925                 assert_eq!(offer.chains(), vec![testnet]);
926                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
927
928                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
929                         .chain(Network::Testnet)
930                         .chain(Network::Testnet)
931                         .build()
932                         .unwrap();
933                 assert!(offer.supports_chain(testnet));
934                 assert_eq!(offer.chains(), vec![testnet]);
935                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![testnet]));
936
937                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
938                         .chain(Network::Bitcoin)
939                         .chain(Network::Testnet)
940                         .build()
941                         .unwrap();
942                 assert!(offer.supports_chain(mainnet));
943                 assert!(offer.supports_chain(testnet));
944                 assert_eq!(offer.chains(), vec![mainnet, testnet]);
945                 assert_eq!(offer.as_tlv_stream().chains, Some(&vec![mainnet, testnet]));
946         }
947
948         #[test]
949         fn builds_offer_with_metadata() {
950                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
951                         .metadata(vec![42; 32]).unwrap()
952                         .build()
953                         .unwrap();
954                 assert_eq!(offer.metadata(), Some(&vec![42; 32]));
955                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![42; 32]));
956
957                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
958                         .metadata(vec![42; 32]).unwrap()
959                         .metadata(vec![43; 32]).unwrap()
960                         .build()
961                         .unwrap();
962                 assert_eq!(offer.metadata(), Some(&vec![43; 32]));
963                 assert_eq!(offer.as_tlv_stream().metadata, Some(&vec![43; 32]));
964         }
965
966         #[test]
967         fn builds_offer_with_metadata_derived() {
968                 let desc = "foo".to_string();
969                 let node_id = recipient_pubkey();
970                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
971                 let entropy = FixedEntropy {};
972                 let secp_ctx = Secp256k1::new();
973
974                 let offer = OfferBuilder
975                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
976                         .amount_msats(1000)
977                         .build().unwrap();
978                 assert_eq!(offer.signing_pubkey(), node_id);
979
980                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
981                         .build().unwrap()
982                         .sign(payer_sign).unwrap();
983                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
984
985                 // Fails verification with altered offer field
986                 let mut tlv_stream = offer.as_tlv_stream();
987                 tlv_stream.amount = Some(100);
988
989                 let mut encoded_offer = Vec::new();
990                 tlv_stream.write(&mut encoded_offer).unwrap();
991
992                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
993                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
994                         .build().unwrap()
995                         .sign(payer_sign).unwrap();
996                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
997
998                 // Fails verification with altered metadata
999                 let mut tlv_stream = offer.as_tlv_stream();
1000                 let metadata = tlv_stream.metadata.unwrap().iter().copied().rev().collect();
1001                 tlv_stream.metadata = Some(&metadata);
1002
1003                 let mut encoded_offer = Vec::new();
1004                 tlv_stream.write(&mut encoded_offer).unwrap();
1005
1006                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1007                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1008                         .build().unwrap()
1009                         .sign(payer_sign).unwrap();
1010                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1011         }
1012
1013         #[test]
1014         fn builds_offer_with_derived_signing_pubkey() {
1015                 let desc = "foo".to_string();
1016                 let node_id = recipient_pubkey();
1017                 let expanded_key = ExpandedKey::new(&KeyMaterial([42; 32]));
1018                 let entropy = FixedEntropy {};
1019                 let secp_ctx = Secp256k1::new();
1020
1021                 let blinded_path = BlindedPath {
1022                         introduction_node_id: pubkey(40),
1023                         blinding_point: pubkey(41),
1024                         blinded_hops: vec![
1025                                 BlindedHop { blinded_node_id: pubkey(42), encrypted_payload: vec![0; 43] },
1026                                 BlindedHop { blinded_node_id: node_id, encrypted_payload: vec![0; 44] },
1027                         ],
1028                 };
1029
1030                 let offer = OfferBuilder
1031                         ::deriving_signing_pubkey(desc, node_id, &expanded_key, &entropy, &secp_ctx)
1032                         .amount_msats(1000)
1033                         .path(blinded_path)
1034                         .build().unwrap();
1035                 assert_ne!(offer.signing_pubkey(), node_id);
1036
1037                 let invoice_request = offer.request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1038                         .build().unwrap()
1039                         .sign(payer_sign).unwrap();
1040                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_ok());
1041
1042                 // Fails verification with altered offer field
1043                 let mut tlv_stream = offer.as_tlv_stream();
1044                 tlv_stream.amount = Some(100);
1045
1046                 let mut encoded_offer = Vec::new();
1047                 tlv_stream.write(&mut encoded_offer).unwrap();
1048
1049                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1050                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1051                         .build().unwrap()
1052                         .sign(payer_sign).unwrap();
1053                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1054
1055                 // Fails verification with altered signing pubkey
1056                 let mut tlv_stream = offer.as_tlv_stream();
1057                 let signing_pubkey = pubkey(1);
1058                 tlv_stream.node_id = Some(&signing_pubkey);
1059
1060                 let mut encoded_offer = Vec::new();
1061                 tlv_stream.write(&mut encoded_offer).unwrap();
1062
1063                 let invoice_request = Offer::try_from(encoded_offer).unwrap()
1064                         .request_invoice(vec![1; 32], payer_pubkey()).unwrap()
1065                         .build().unwrap()
1066                         .sign(payer_sign).unwrap();
1067                 assert!(invoice_request.verify(&expanded_key, &secp_ctx).is_err());
1068         }
1069
1070         #[test]
1071         fn builds_offer_with_amount() {
1072                 let bitcoin_amount = Amount::Bitcoin { amount_msats: 1000 };
1073                 let currency_amount = Amount::Currency { iso4217_code: *b"USD", amount: 10 };
1074
1075                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1076                         .amount_msats(1000)
1077                         .build()
1078                         .unwrap();
1079                 let tlv_stream = offer.as_tlv_stream();
1080                 assert_eq!(offer.amount(), Some(&bitcoin_amount));
1081                 assert_eq!(tlv_stream.amount, Some(1000));
1082                 assert_eq!(tlv_stream.currency, None);
1083
1084                 let builder = OfferBuilder::new("foo".into(), pubkey(42))
1085                         .amount(currency_amount.clone());
1086                 let tlv_stream = builder.offer.as_tlv_stream();
1087                 assert_eq!(builder.offer.amount, Some(currency_amount.clone()));
1088                 assert_eq!(tlv_stream.amount, Some(10));
1089                 assert_eq!(tlv_stream.currency, Some(b"USD"));
1090                 match builder.build() {
1091                         Ok(_) => panic!("expected error"),
1092                         Err(e) => assert_eq!(e, SemanticError::UnsupportedCurrency),
1093                 }
1094
1095                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1096                         .amount(currency_amount.clone())
1097                         .amount(bitcoin_amount.clone())
1098                         .build()
1099                         .unwrap();
1100                 let tlv_stream = offer.as_tlv_stream();
1101                 assert_eq!(tlv_stream.amount, Some(1000));
1102                 assert_eq!(tlv_stream.currency, None);
1103
1104                 let invalid_amount = Amount::Bitcoin { amount_msats: MAX_VALUE_MSAT + 1 };
1105                 match OfferBuilder::new("foo".into(), pubkey(42)).amount(invalid_amount).build() {
1106                         Ok(_) => panic!("expected error"),
1107                         Err(e) => assert_eq!(e, SemanticError::InvalidAmount),
1108                 }
1109         }
1110
1111         #[test]
1112         fn builds_offer_with_features() {
1113                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1114                         .features_unchecked(OfferFeatures::unknown())
1115                         .build()
1116                         .unwrap();
1117                 assert_eq!(offer.features(), &OfferFeatures::unknown());
1118                 assert_eq!(offer.as_tlv_stream().features, Some(&OfferFeatures::unknown()));
1119
1120                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1121                         .features_unchecked(OfferFeatures::unknown())
1122                         .features_unchecked(OfferFeatures::empty())
1123                         .build()
1124                         .unwrap();
1125                 assert_eq!(offer.features(), &OfferFeatures::empty());
1126                 assert_eq!(offer.as_tlv_stream().features, None);
1127         }
1128
1129         #[test]
1130         fn builds_offer_with_absolute_expiry() {
1131                 let future_expiry = Duration::from_secs(u64::max_value());
1132                 let past_expiry = Duration::from_secs(0);
1133
1134                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1135                         .absolute_expiry(future_expiry)
1136                         .build()
1137                         .unwrap();
1138                 #[cfg(feature = "std")]
1139                 assert!(!offer.is_expired());
1140                 assert_eq!(offer.absolute_expiry(), Some(future_expiry));
1141                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(future_expiry.as_secs()));
1142
1143                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1144                         .absolute_expiry(future_expiry)
1145                         .absolute_expiry(past_expiry)
1146                         .build()
1147                         .unwrap();
1148                 #[cfg(feature = "std")]
1149                 assert!(offer.is_expired());
1150                 assert_eq!(offer.absolute_expiry(), Some(past_expiry));
1151                 assert_eq!(offer.as_tlv_stream().absolute_expiry, Some(past_expiry.as_secs()));
1152         }
1153
1154         #[test]
1155         fn builds_offer_with_paths() {
1156                 let paths = vec![
1157                         BlindedPath {
1158                                 introduction_node_id: pubkey(40),
1159                                 blinding_point: pubkey(41),
1160                                 blinded_hops: vec![
1161                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1162                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1163                                 ],
1164                         },
1165                         BlindedPath {
1166                                 introduction_node_id: pubkey(40),
1167                                 blinding_point: pubkey(41),
1168                                 blinded_hops: vec![
1169                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1170                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1171                                 ],
1172                         },
1173                 ];
1174
1175                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1176                         .path(paths[0].clone())
1177                         .path(paths[1].clone())
1178                         .build()
1179                         .unwrap();
1180                 let tlv_stream = offer.as_tlv_stream();
1181                 assert_eq!(offer.paths(), paths.as_slice());
1182                 assert_eq!(offer.signing_pubkey(), pubkey(42));
1183                 assert_ne!(pubkey(42), pubkey(44));
1184                 assert_eq!(tlv_stream.paths, Some(&paths));
1185                 assert_eq!(tlv_stream.node_id, Some(&pubkey(42)));
1186         }
1187
1188         #[test]
1189         fn builds_offer_with_issuer() {
1190                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1191                         .issuer("bar".into())
1192                         .build()
1193                         .unwrap();
1194                 assert_eq!(offer.issuer(), Some(PrintableString("bar")));
1195                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("bar")));
1196
1197                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1198                         .issuer("bar".into())
1199                         .issuer("baz".into())
1200                         .build()
1201                         .unwrap();
1202                 assert_eq!(offer.issuer(), Some(PrintableString("baz")));
1203                 assert_eq!(offer.as_tlv_stream().issuer, Some(&String::from("baz")));
1204         }
1205
1206         #[test]
1207         fn builds_offer_with_supported_quantity() {
1208                 let one = NonZeroU64::new(1).unwrap();
1209                 let ten = NonZeroU64::new(10).unwrap();
1210
1211                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1212                         .supported_quantity(Quantity::One)
1213                         .build()
1214                         .unwrap();
1215                 let tlv_stream = offer.as_tlv_stream();
1216                 assert_eq!(offer.supported_quantity(), Quantity::One);
1217                 assert_eq!(tlv_stream.quantity_max, None);
1218
1219                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1220                         .supported_quantity(Quantity::Unbounded)
1221                         .build()
1222                         .unwrap();
1223                 let tlv_stream = offer.as_tlv_stream();
1224                 assert_eq!(offer.supported_quantity(), Quantity::Unbounded);
1225                 assert_eq!(tlv_stream.quantity_max, Some(0));
1226
1227                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1228                         .supported_quantity(Quantity::Bounded(ten))
1229                         .build()
1230                         .unwrap();
1231                 let tlv_stream = offer.as_tlv_stream();
1232                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(ten));
1233                 assert_eq!(tlv_stream.quantity_max, Some(10));
1234
1235                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1236                         .supported_quantity(Quantity::Bounded(one))
1237                         .build()
1238                         .unwrap();
1239                 let tlv_stream = offer.as_tlv_stream();
1240                 assert_eq!(offer.supported_quantity(), Quantity::Bounded(one));
1241                 assert_eq!(tlv_stream.quantity_max, Some(1));
1242
1243                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1244                         .supported_quantity(Quantity::Bounded(ten))
1245                         .supported_quantity(Quantity::One)
1246                         .build()
1247                         .unwrap();
1248                 let tlv_stream = offer.as_tlv_stream();
1249                 assert_eq!(offer.supported_quantity(), Quantity::One);
1250                 assert_eq!(tlv_stream.quantity_max, None);
1251         }
1252
1253         #[test]
1254         fn fails_requesting_invoice_with_unknown_required_features() {
1255                 match OfferBuilder::new("foo".into(), pubkey(42))
1256                         .features_unchecked(OfferFeatures::unknown())
1257                         .build().unwrap()
1258                         .request_invoice(vec![1; 32], pubkey(43))
1259                 {
1260                         Ok(_) => panic!("expected error"),
1261                         Err(e) => assert_eq!(e, SemanticError::UnknownRequiredFeatures),
1262                 }
1263         }
1264
1265         #[test]
1266         fn parses_offer_with_chains() {
1267                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1268                         .chain(Network::Bitcoin)
1269                         .chain(Network::Testnet)
1270                         .build()
1271                         .unwrap();
1272                 if let Err(e) = offer.to_string().parse::<Offer>() {
1273                         panic!("error parsing offer: {:?}", e);
1274                 }
1275         }
1276
1277         #[test]
1278         fn parses_offer_with_amount() {
1279                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1280                         .amount(Amount::Bitcoin { amount_msats: 1000 })
1281                         .build()
1282                         .unwrap();
1283                 if let Err(e) = offer.to_string().parse::<Offer>() {
1284                         panic!("error parsing offer: {:?}", e);
1285                 }
1286
1287                 let mut tlv_stream = offer.as_tlv_stream();
1288                 tlv_stream.amount = Some(1000);
1289                 tlv_stream.currency = Some(b"USD");
1290
1291                 let mut encoded_offer = Vec::new();
1292                 tlv_stream.write(&mut encoded_offer).unwrap();
1293
1294                 if let Err(e) = Offer::try_from(encoded_offer) {
1295                         panic!("error parsing offer: {:?}", e);
1296                 }
1297
1298                 let mut tlv_stream = offer.as_tlv_stream();
1299                 tlv_stream.amount = None;
1300                 tlv_stream.currency = Some(b"USD");
1301
1302                 let mut encoded_offer = Vec::new();
1303                 tlv_stream.write(&mut encoded_offer).unwrap();
1304
1305                 match Offer::try_from(encoded_offer) {
1306                         Ok(_) => panic!("expected error"),
1307                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingAmount)),
1308                 }
1309
1310                 let mut tlv_stream = offer.as_tlv_stream();
1311                 tlv_stream.amount = Some(MAX_VALUE_MSAT + 1);
1312                 tlv_stream.currency = None;
1313
1314                 let mut encoded_offer = Vec::new();
1315                 tlv_stream.write(&mut encoded_offer).unwrap();
1316
1317                 match Offer::try_from(encoded_offer) {
1318                         Ok(_) => panic!("expected error"),
1319                         Err(e) => assert_eq!(e, ParseError::InvalidSemantics(SemanticError::InvalidAmount)),
1320                 }
1321         }
1322
1323         #[test]
1324         fn parses_offer_with_description() {
1325                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1326                 if let Err(e) = offer.to_string().parse::<Offer>() {
1327                         panic!("error parsing offer: {:?}", e);
1328                 }
1329
1330                 let mut tlv_stream = offer.as_tlv_stream();
1331                 tlv_stream.description = None;
1332
1333                 let mut encoded_offer = Vec::new();
1334                 tlv_stream.write(&mut encoded_offer).unwrap();
1335
1336                 match Offer::try_from(encoded_offer) {
1337                         Ok(_) => panic!("expected error"),
1338                         Err(e) => {
1339                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingDescription));
1340                         },
1341                 }
1342         }
1343
1344         #[test]
1345         fn parses_offer_with_paths() {
1346                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1347                         .path(BlindedPath {
1348                                 introduction_node_id: pubkey(40),
1349                                 blinding_point: pubkey(41),
1350                                 blinded_hops: vec![
1351                                         BlindedHop { blinded_node_id: pubkey(43), encrypted_payload: vec![0; 43] },
1352                                         BlindedHop { blinded_node_id: pubkey(44), encrypted_payload: vec![0; 44] },
1353                                 ],
1354                         })
1355                         .path(BlindedPath {
1356                                 introduction_node_id: pubkey(40),
1357                                 blinding_point: pubkey(41),
1358                                 blinded_hops: vec![
1359                                         BlindedHop { blinded_node_id: pubkey(45), encrypted_payload: vec![0; 45] },
1360                                         BlindedHop { blinded_node_id: pubkey(46), encrypted_payload: vec![0; 46] },
1361                                 ],
1362                         })
1363                         .build()
1364                         .unwrap();
1365                 if let Err(e) = offer.to_string().parse::<Offer>() {
1366                         panic!("error parsing offer: {:?}", e);
1367                 }
1368
1369                 let mut builder = OfferBuilder::new("foo".into(), pubkey(42));
1370                 builder.offer.paths = Some(vec![]);
1371
1372                 let offer = builder.build().unwrap();
1373                 if let Err(e) = offer.to_string().parse::<Offer>() {
1374                         panic!("error parsing offer: {:?}", e);
1375                 }
1376         }
1377
1378         #[test]
1379         fn parses_offer_with_quantity() {
1380                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1381                         .supported_quantity(Quantity::One)
1382                         .build()
1383                         .unwrap();
1384                 if let Err(e) = offer.to_string().parse::<Offer>() {
1385                         panic!("error parsing offer: {:?}", e);
1386                 }
1387
1388                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1389                         .supported_quantity(Quantity::Unbounded)
1390                         .build()
1391                         .unwrap();
1392                 if let Err(e) = offer.to_string().parse::<Offer>() {
1393                         panic!("error parsing offer: {:?}", e);
1394                 }
1395
1396                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1397                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(10).unwrap()))
1398                         .build()
1399                         .unwrap();
1400                 if let Err(e) = offer.to_string().parse::<Offer>() {
1401                         panic!("error parsing offer: {:?}", e);
1402                 }
1403
1404                 let offer = OfferBuilder::new("foo".into(), pubkey(42))
1405                         .supported_quantity(Quantity::Bounded(NonZeroU64::new(1).unwrap()))
1406                         .build()
1407                         .unwrap();
1408                 if let Err(e) = offer.to_string().parse::<Offer>() {
1409                         panic!("error parsing offer: {:?}", e);
1410                 }
1411         }
1412
1413         #[test]
1414         fn parses_offer_with_node_id() {
1415                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1416                 if let Err(e) = offer.to_string().parse::<Offer>() {
1417                         panic!("error parsing offer: {:?}", e);
1418                 }
1419
1420                 let mut tlv_stream = offer.as_tlv_stream();
1421                 tlv_stream.node_id = None;
1422
1423                 let mut encoded_offer = Vec::new();
1424                 tlv_stream.write(&mut encoded_offer).unwrap();
1425
1426                 match Offer::try_from(encoded_offer) {
1427                         Ok(_) => panic!("expected error"),
1428                         Err(e) => {
1429                                 assert_eq!(e, ParseError::InvalidSemantics(SemanticError::MissingSigningPubkey));
1430                         },
1431                 }
1432         }
1433
1434         #[test]
1435         fn fails_parsing_offer_with_extra_tlv_records() {
1436                 let offer = OfferBuilder::new("foo".into(), pubkey(42)).build().unwrap();
1437
1438                 let mut encoded_offer = Vec::new();
1439                 offer.write(&mut encoded_offer).unwrap();
1440                 BigSize(80).write(&mut encoded_offer).unwrap();
1441                 BigSize(32).write(&mut encoded_offer).unwrap();
1442                 [42u8; 32].write(&mut encoded_offer).unwrap();
1443
1444                 match Offer::try_from(encoded_offer) {
1445                         Ok(_) => panic!("expected error"),
1446                         Err(e) => assert_eq!(e, ParseError::Decode(DecodeError::InvalidValue)),
1447                 }
1448         }
1449 }
1450
1451 #[cfg(test)]
1452 mod bech32_tests {
1453         use super::{Offer, ParseError};
1454         use bitcoin::bech32;
1455         use crate::ln::msgs::DecodeError;
1456
1457         // TODO: Remove once test vectors are updated.
1458         #[ignore]
1459         #[test]
1460         fn encodes_offer_as_bech32_without_checksum() {
1461                 let encoded_offer = "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy";
1462                 let offer = dbg!(encoded_offer.parse::<Offer>().unwrap());
1463                 let reencoded_offer = offer.to_string();
1464                 dbg!(reencoded_offer.parse::<Offer>().unwrap());
1465                 assert_eq!(reencoded_offer, encoded_offer);
1466         }
1467
1468         // TODO: Remove once test vectors are updated.
1469         #[ignore]
1470         #[test]
1471         fn parses_bech32_encoded_offers() {
1472                 let offers = [
1473                         // BOLT 12 test vectors
1474                         "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
1475                         "l+no1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
1476                         "l+no1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
1477                         "lno1qcp4256ypqpq+86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn0+0fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0+sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qs+y",
1478                         "lno1qcp4256ypqpq+ 86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn0+  0fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0+\nsqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43l+\r\nastpwuh73k29qs+\r  y",
1479                         // Two blinded paths
1480                         "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",
1481                 ];
1482                 for encoded_offer in &offers {
1483                         if let Err(e) = encoded_offer.parse::<Offer>() {
1484                                 panic!("Invalid offer ({:?}): {}", e, encoded_offer);
1485                         }
1486                 }
1487         }
1488
1489         #[test]
1490         fn fails_parsing_bech32_encoded_offers_with_invalid_continuations() {
1491                 let offers = [
1492                         // BOLT 12 test vectors
1493                         "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy+",
1494                         "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy+ ",
1495                         "+lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
1496                         "+ lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
1497                         "ln++o1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy",
1498                 ];
1499                 for encoded_offer in &offers {
1500                         match encoded_offer.parse::<Offer>() {
1501                                 Ok(_) => panic!("Valid offer: {}", encoded_offer),
1502                                 Err(e) => assert_eq!(e, ParseError::InvalidContinuation),
1503                         }
1504                 }
1505
1506         }
1507
1508         #[test]
1509         fn fails_parsing_bech32_encoded_offer_with_invalid_hrp() {
1510                 let encoded_offer = "lni1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsy";
1511                 match encoded_offer.parse::<Offer>() {
1512                         Ok(_) => panic!("Valid offer: {}", encoded_offer),
1513                         Err(e) => assert_eq!(e, ParseError::InvalidBech32Hrp),
1514                 }
1515         }
1516
1517         #[test]
1518         fn fails_parsing_bech32_encoded_offer_with_invalid_bech32_data() {
1519                 let encoded_offer = "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qso";
1520                 match encoded_offer.parse::<Offer>() {
1521                         Ok(_) => panic!("Valid offer: {}", encoded_offer),
1522                         Err(e) => assert_eq!(e, ParseError::Bech32(bech32::Error::InvalidChar('o'))),
1523                 }
1524         }
1525
1526         #[test]
1527         fn fails_parsing_bech32_encoded_offer_with_invalid_tlv_data() {
1528                 let encoded_offer = "lno1qcp4256ypqpq86q2pucnq42ngssx2an9wfujqerp0y2pqun4wd68jtn00fkxzcnn9ehhyec6qgqsz83qfwdpl28qqmc78ymlvhmxcsywdk5wrjnj36jryg488qwlrnzyjczlqsp9nyu4phcg6dqhlhzgxagfu7zh3d9re0sqp9ts2yfugvnnm9gxkcnnnkdpa084a6t520h5zhkxsdnghvpukvd43lastpwuh73k29qsyqqqqq";
1529                 match encoded_offer.parse::<Offer>() {
1530                         Ok(_) => panic!("Valid offer: {}", encoded_offer),
1531                         Err(e) => assert_eq!(e, ParseError::Decode(DecodeError::InvalidValue)),
1532                 }
1533         }
1534 }