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[rust-lightning] / lightning-invoice / src / lib.rs
1 // Prefix these with `rustdoc::` when we update our MSRV to be >= 1.52 to remove warnings.
2 #![deny(broken_intra_doc_links)]
3 #![deny(private_intra_doc_links)]
4
5 #![deny(missing_docs)]
6 #![deny(non_upper_case_globals)]
7 #![deny(non_camel_case_types)]
8 #![deny(non_snake_case)]
9 #![deny(unused_mut)]
10
11 #![cfg_attr(docsrs, feature(doc_auto_cfg))]
12
13 #![cfg_attr(feature = "strict", deny(warnings))]
14 #![cfg_attr(all(not(feature = "std"), not(test)), no_std)]
15
16 //! This crate provides data structures to represent
17 //! [lightning BOLT11](https://github.com/lightning/bolts/blob/master/11-payment-encoding.md)
18 //! invoices and functions to create, encode and decode these. If you just want to use the standard
19 //! en-/decoding functionality this should get you started:
20 //!
21 //!   * For parsing use `str::parse::<Invoice>(&self)` (see the docs of `impl FromStr for Invoice`)
22 //!   * For constructing invoices use the `InvoiceBuilder`
23 //!   * For serializing invoices use the `Display`/`ToString` traits
24
25 #[cfg(not(any(feature = "std", feature = "no-std")))]
26 compile_error!("at least one of the `std` or `no-std` features must be enabled");
27
28 pub mod payment;
29 pub mod utils;
30
31 pub(crate) mod time_utils;
32
33 extern crate bech32;
34 extern crate bitcoin_hashes;
35 #[macro_use] extern crate lightning;
36 extern crate num_traits;
37 extern crate secp256k1;
38 extern crate alloc;
39 #[cfg(any(test, feature = "std"))]
40 extern crate core;
41 #[cfg(feature = "serde")]
42 extern crate serde;
43
44 #[cfg(feature = "std")]
45 use std::time::SystemTime;
46
47 use bech32::u5;
48 use bitcoin_hashes::Hash;
49 use bitcoin_hashes::sha256;
50 use lightning::ln::PaymentSecret;
51 use lightning::ln::features::InvoiceFeatures;
52 #[cfg(any(doc, test))]
53 use lightning::routing::gossip::RoutingFees;
54 use lightning::routing::router::RouteHint;
55 use lightning::util::invoice::construct_invoice_preimage;
56
57 use secp256k1::PublicKey;
58 use secp256k1::{Message, Secp256k1};
59 use secp256k1::ecdsa::RecoverableSignature;
60
61 use core::fmt::{Display, Formatter, self};
62 use core::iter::FilterMap;
63 use core::num::ParseIntError;
64 use core::ops::Deref;
65 use core::slice::Iter;
66 use core::time::Duration;
67 use core::str;
68
69 #[cfg(feature = "serde")]
70 use serde::{Deserialize, Deserializer,Serialize, Serializer, de::Error};
71
72 mod de;
73 mod ser;
74 mod tb;
75
76 mod prelude {
77         #[cfg(feature = "hashbrown")]
78         extern crate hashbrown;
79
80         pub use alloc::{vec, vec::Vec, string::String, collections::VecDeque, boxed::Box};
81         #[cfg(not(feature = "hashbrown"))]
82         pub use std::collections::{HashMap, HashSet, hash_map};
83         #[cfg(feature = "hashbrown")]
84         pub use self::hashbrown::{HashMap, HashSet, hash_map};
85
86         pub use alloc::string::ToString;
87 }
88
89 use crate::prelude::*;
90
91 /// Sync compat for std/no_std
92 #[cfg(feature = "std")]
93 mod sync {
94         pub use ::std::sync::{Mutex, MutexGuard};
95 }
96
97 /// Sync compat for std/no_std
98 #[cfg(not(feature = "std"))]
99 mod sync;
100
101 /// Errors that indicate what is wrong with the invoice. They have some granularity for debug
102 /// reasons, but should generally result in an "invalid BOLT11 invoice" message for the user.
103 #[allow(missing_docs)]
104 #[derive(PartialEq, Eq, Debug, Clone)]
105 pub enum ParseError {
106         Bech32Error(bech32::Error),
107         ParseAmountError(ParseIntError),
108         MalformedSignature(secp256k1::Error),
109         BadPrefix,
110         UnknownCurrency,
111         UnknownSiPrefix,
112         MalformedHRP,
113         TooShortDataPart,
114         UnexpectedEndOfTaggedFields,
115         DescriptionDecodeError(str::Utf8Error),
116         PaddingError,
117         IntegerOverflowError,
118         InvalidSegWitProgramLength,
119         InvalidPubKeyHashLength,
120         InvalidScriptHashLength,
121         InvalidRecoveryId,
122         InvalidSliceLength(String),
123
124         /// Not an error, but used internally to signal that a part of the invoice should be ignored
125         /// according to BOLT11
126         Skip,
127 }
128
129 /// Indicates that something went wrong while parsing or validating the invoice. Parsing errors
130 /// should be mostly seen as opaque and are only there for debugging reasons. Semantic errors
131 /// like wrong signatures, missing fields etc. could mean that someone tampered with the invoice.
132 #[derive(PartialEq, Eq, Debug, Clone)]
133 pub enum ParseOrSemanticError {
134         /// The invoice couldn't be decoded
135         ParseError(ParseError),
136
137         /// The invoice could be decoded but violates the BOLT11 standard
138         SemanticError(crate::SemanticError),
139 }
140
141 /// The number of bits used to represent timestamps as defined in BOLT 11.
142 const TIMESTAMP_BITS: usize = 35;
143
144 /// The maximum timestamp as [`Duration::as_secs`] since the Unix epoch allowed by [`BOLT 11`].
145 ///
146 /// [BOLT 11]: https://github.com/lightning/bolts/blob/master/11-payment-encoding.md
147 pub const MAX_TIMESTAMP: u64 = (1 << TIMESTAMP_BITS) - 1;
148
149 /// Default expiry time as defined by [BOLT 11].
150 ///
151 /// [BOLT 11]: https://github.com/lightning/bolts/blob/master/11-payment-encoding.md
152 pub const DEFAULT_EXPIRY_TIME: u64 = 3600;
153
154 /// Default minimum final CLTV expiry as defined by [BOLT 11].
155 ///
156 /// Note that this is *not* the same value as rust-lightning's minimum CLTV expiry, which is
157 /// provided in [`MIN_FINAL_CLTV_EXPIRY_DELTA`].
158 ///
159 /// [BOLT 11]: https://github.com/lightning/bolts/blob/master/11-payment-encoding.md
160 /// [`MIN_FINAL_CLTV_EXPIRY_DELTA`]: lightning::ln::channelmanager::MIN_FINAL_CLTV_EXPIRY_DELTA
161 pub const DEFAULT_MIN_FINAL_CLTV_EXPIRY_DELTA: u64 = 18;
162
163 /// Builder for `Invoice`s. It's the most convenient and advised way to use this library. It ensures
164 /// that only a semantically and syntactically correct Invoice can be built using it.
165 ///
166 /// ```
167 /// extern crate secp256k1;
168 /// extern crate lightning;
169 /// extern crate lightning_invoice;
170 /// extern crate bitcoin_hashes;
171 ///
172 /// use bitcoin_hashes::Hash;
173 /// use bitcoin_hashes::sha256;
174 ///
175 /// use secp256k1::Secp256k1;
176 /// use secp256k1::SecretKey;
177 ///
178 /// use lightning::ln::PaymentSecret;
179 ///
180 /// use lightning_invoice::{Currency, InvoiceBuilder};
181 ///
182 /// # #[cfg(not(feature = "std"))]
183 /// # fn main() {}
184 /// # #[cfg(feature = "std")]
185 /// # fn main() {
186 /// let private_key = SecretKey::from_slice(
187 ///             &[
188 ///                     0xe1, 0x26, 0xf6, 0x8f, 0x7e, 0xaf, 0xcc, 0x8b, 0x74, 0xf5, 0x4d, 0x26, 0x9f,
189 ///                     0xe2, 0x06, 0xbe, 0x71, 0x50, 0x00, 0xf9, 0x4d, 0xac, 0x06, 0x7d, 0x1c, 0x04,
190 ///             0xa8, 0xca, 0x3b, 0x2d, 0xb7, 0x34
191 ///     ][..]
192 ///     ).unwrap();
193 ///
194 /// let payment_hash = sha256::Hash::from_slice(&[0; 32][..]).unwrap();
195 /// let payment_secret = PaymentSecret([42u8; 32]);
196 ///
197 /// let invoice = InvoiceBuilder::new(Currency::Bitcoin)
198 ///     .description("Coins pls!".into())
199 ///     .payment_hash(payment_hash)
200 ///     .payment_secret(payment_secret)
201 ///     .current_timestamp()
202 ///     .min_final_cltv_expiry_delta(144)
203 ///     .build_signed(|hash| {
204 ///             Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)
205 ///     })
206 ///     .unwrap();
207 ///
208 /// assert!(invoice.to_string().starts_with("lnbc1"));
209 /// # }
210 /// ```
211 ///
212 /// # Type parameters
213 /// The two parameters `D` and `H` signal if the builder already contains the correct amount of the
214 /// given field:
215 ///  * `D`: exactly one `Description` or `DescriptionHash`
216 ///  * `H`: exactly one `PaymentHash`
217 ///  * `T`: the timestamp is set
218 ///
219 /// (C-not exported) as we likely need to manually select one set of boolean type parameters.
220 #[derive(Eq, PartialEq, Debug, Clone)]
221 pub struct InvoiceBuilder<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> {
222         currency: Currency,
223         amount: Option<u64>,
224         si_prefix: Option<SiPrefix>,
225         timestamp: Option<PositiveTimestamp>,
226         tagged_fields: Vec<TaggedField>,
227         error: Option<CreationError>,
228
229         phantom_d: core::marker::PhantomData<D>,
230         phantom_h: core::marker::PhantomData<H>,
231         phantom_t: core::marker::PhantomData<T>,
232         phantom_c: core::marker::PhantomData<C>,
233         phantom_s: core::marker::PhantomData<S>,
234 }
235
236 /// Represents a syntactically and semantically correct lightning BOLT11 invoice.
237 ///
238 /// There are three ways to construct an `Invoice`:
239 ///  1. using `InvoiceBuilder`
240 ///  2. using `Invoice::from_signed(SignedRawInvoice)`
241 ///  3. using `str::parse::<Invoice>(&str)`
242 #[derive(Eq, PartialEq, Debug, Clone, Hash)]
243 pub struct Invoice {
244         signed_invoice: SignedRawInvoice,
245 }
246
247 /// Represents the description of an invoice which has to be either a directly included string or
248 /// a hash of a description provided out of band.
249 ///
250 /// (C-not exported) As we don't have a good way to map the reference lifetimes making this
251 /// practically impossible to use safely in languages like C.
252 #[derive(Eq, PartialEq, Debug, Clone)]
253 pub enum InvoiceDescription<'f> {
254         /// Reference to the directly supplied description in the invoice
255         Direct(&'f Description),
256
257         /// Reference to the description's hash included in the invoice
258         Hash(&'f Sha256),
259 }
260
261 /// Represents a signed `RawInvoice` with cached hash. The signature is not checked and may be
262 /// invalid.
263 ///
264 /// # Invariants
265 /// The hash has to be either from the deserialized invoice or from the serialized `raw_invoice`.
266 #[derive(Eq, PartialEq, Debug, Clone, Hash)]
267 pub struct SignedRawInvoice {
268         /// The rawInvoice that the signature belongs to
269         raw_invoice: RawInvoice,
270
271         /// Hash of the `RawInvoice` that will be used to check the signature.
272         ///
273         /// * if the `SignedRawInvoice` was deserialized the hash is of from the original encoded form,
274         /// since it's not guaranteed that encoding it again will lead to the same result since integers
275         /// could have been encoded with leading zeroes etc.
276         /// * if the `SignedRawInvoice` was constructed manually the hash will be the calculated hash
277         /// from the `RawInvoice`
278         hash: [u8; 32],
279
280         /// signature of the payment request
281         signature: InvoiceSignature,
282 }
283
284 /// Represents an syntactically correct Invoice for a payment on the lightning network,
285 /// but without the signature information.
286 /// De- and encoding should not lead to information loss but may lead to different hashes.
287 ///
288 /// For methods without docs see the corresponding methods in `Invoice`.
289 #[derive(Eq, PartialEq, Debug, Clone, Hash)]
290 pub struct RawInvoice {
291         /// human readable part
292         pub hrp: RawHrp,
293
294         /// data part
295         pub data: RawDataPart,
296 }
297
298 /// Data of the `RawInvoice` that is encoded in the human readable part
299 ///
300 /// (C-not exported) As we don't yet support `Option<Enum>`
301 #[derive(Eq, PartialEq, Debug, Clone, Hash)]
302 pub struct RawHrp {
303         /// The currency deferred from the 3rd and 4th character of the bech32 transaction
304         pub currency: Currency,
305
306         /// The amount that, multiplied by the SI prefix, has to be payed
307         pub raw_amount: Option<u64>,
308
309         /// SI prefix that gets multiplied with the `raw_amount`
310         pub si_prefix: Option<SiPrefix>,
311 }
312
313 /// Data of the `RawInvoice` that is encoded in the data part
314 #[derive(Eq, PartialEq, Debug, Clone, Hash)]
315 pub struct RawDataPart {
316         /// generation time of the invoice
317         pub timestamp: PositiveTimestamp,
318
319         /// tagged fields of the payment request
320         pub tagged_fields: Vec<RawTaggedField>,
321 }
322
323 /// A timestamp that refers to a date after 1 January 1970.
324 ///
325 /// # Invariants
326 ///
327 /// The Unix timestamp representing the stored time has to be positive and no greater than
328 /// [`MAX_TIMESTAMP`].
329 #[derive(Eq, PartialEq, Debug, Clone, Hash)]
330 pub struct PositiveTimestamp(Duration);
331
332 /// SI prefixes for the human readable part
333 #[derive(Eq, PartialEq, Debug, Clone, Copy, Hash)]
334 pub enum SiPrefix {
335         /// 10^-3
336         Milli,
337         /// 10^-6
338         Micro,
339         /// 10^-9
340         Nano,
341         /// 10^-12
342         Pico,
343 }
344
345 impl SiPrefix {
346         /// Returns the multiplier to go from a BTC value to picoBTC implied by this SiPrefix.
347         /// This is effectively 10^12 * the prefix multiplier
348         pub fn multiplier(&self) -> u64 {
349                 match *self {
350                         SiPrefix::Milli => 1_000_000_000,
351                         SiPrefix::Micro => 1_000_000,
352                         SiPrefix::Nano => 1_000,
353                         SiPrefix::Pico => 1,
354                 }
355         }
356
357         /// Returns all enum variants of `SiPrefix` sorted in descending order of their associated
358         /// multiplier.
359         ///
360         /// (C-not exported) As we don't yet support a slice of enums, and also because this function
361         /// isn't the most critical to expose.
362         pub fn values_desc() -> &'static [SiPrefix] {
363                 use crate::SiPrefix::*;
364                 static VALUES: [SiPrefix; 4] = [Milli, Micro, Nano, Pico];
365                 &VALUES
366         }
367 }
368
369 /// Enum representing the crypto currencies (or networks) supported by this library
370 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
371 pub enum Currency {
372         /// Bitcoin mainnet
373         Bitcoin,
374
375         /// Bitcoin testnet
376         BitcoinTestnet,
377
378         /// Bitcoin regtest
379         Regtest,
380
381         /// Bitcoin simnet
382         Simnet,
383
384         /// Bitcoin signet
385         Signet,
386 }
387
388 /// Tagged field which may have an unknown tag
389 ///
390 /// (C-not exported) as we don't currently support TaggedField
391 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
392 pub enum RawTaggedField {
393         /// Parsed tagged field with known tag
394         KnownSemantics(TaggedField),
395         /// tagged field which was not parsed due to an unknown tag or undefined field semantics
396         UnknownSemantics(Vec<u5>),
397 }
398
399 /// Tagged field with known tag
400 ///
401 /// For descriptions of the enum values please refer to the enclosed type's docs.
402 ///
403 /// (C-not exported) As we don't yet support enum variants with the same name the struct contained
404 /// in the variant.
405 #[allow(missing_docs)]
406 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
407 pub enum TaggedField {
408         PaymentHash(Sha256),
409         Description(Description),
410         PayeePubKey(PayeePubKey),
411         DescriptionHash(Sha256),
412         ExpiryTime(ExpiryTime),
413         MinFinalCltvExpiryDelta(MinFinalCltvExpiryDelta),
414         Fallback(Fallback),
415         PrivateRoute(PrivateRoute),
416         PaymentSecret(PaymentSecret),
417         Features(InvoiceFeatures),
418 }
419
420 /// SHA-256 hash
421 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
422 pub struct Sha256(/// (C-not exported) as the native hash types are not currently mapped
423         pub sha256::Hash);
424
425 /// Description string
426 ///
427 /// # Invariants
428 /// The description can be at most 639 __bytes__ long
429 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
430 pub struct Description(String);
431
432 /// Payee public key
433 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
434 pub struct PayeePubKey(pub PublicKey);
435
436 /// Positive duration that defines when (relatively to the timestamp) in the future the invoice
437 /// expires
438 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
439 pub struct ExpiryTime(Duration);
440
441 /// `min_final_cltv_expiry_delta` to use for the last HTLC in the route
442 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
443 pub struct MinFinalCltvExpiryDelta(pub u64);
444
445 // TODO: better types instead onf byte arrays
446 /// Fallback address in case no LN payment is possible
447 #[allow(missing_docs)]
448 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
449 pub enum Fallback {
450         SegWitProgram {
451                 version: u5,
452                 program: Vec<u8>,
453         },
454         PubKeyHash([u8; 20]),
455         ScriptHash([u8; 20]),
456 }
457
458 /// Recoverable signature
459 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
460 pub struct InvoiceSignature(pub RecoverableSignature);
461
462 /// Private routing information
463 ///
464 /// # Invariants
465 /// The encoded route has to be <1024 5bit characters long (<=639 bytes or <=12 hops)
466 ///
467 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
468 pub struct PrivateRoute(RouteHint);
469
470 /// Tag constants as specified in BOLT11
471 #[allow(missing_docs)]
472 pub mod constants {
473         pub const TAG_PAYMENT_HASH: u8 = 1;
474         pub const TAG_DESCRIPTION: u8 = 13;
475         pub const TAG_PAYEE_PUB_KEY: u8 = 19;
476         pub const TAG_DESCRIPTION_HASH: u8 = 23;
477         pub const TAG_EXPIRY_TIME: u8 = 6;
478         pub const TAG_MIN_FINAL_CLTV_EXPIRY_DELTA: u8 = 24;
479         pub const TAG_FALLBACK: u8 = 9;
480         pub const TAG_PRIVATE_ROUTE: u8 = 3;
481         pub const TAG_PAYMENT_SECRET: u8 = 16;
482         pub const TAG_FEATURES: u8 = 5;
483 }
484
485 impl InvoiceBuilder<tb::False, tb::False, tb::False, tb::False, tb::False> {
486         /// Construct new, empty `InvoiceBuilder`. All necessary fields have to be filled first before
487         /// `InvoiceBuilder::build(self)` becomes available.
488         pub fn new(currrency: Currency) -> Self {
489                 InvoiceBuilder {
490                         currency: currrency,
491                         amount: None,
492                         si_prefix: None,
493                         timestamp: None,
494                         tagged_fields: Vec::new(),
495                         error: None,
496
497                         phantom_d: core::marker::PhantomData,
498                         phantom_h: core::marker::PhantomData,
499                         phantom_t: core::marker::PhantomData,
500                         phantom_c: core::marker::PhantomData,
501                         phantom_s: core::marker::PhantomData,
502                 }
503         }
504 }
505
506 impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, T, C, S> {
507         /// Helper function to set the completeness flags.
508         fn set_flags<DN: tb::Bool, HN: tb::Bool, TN: tb::Bool, CN: tb::Bool, SN: tb::Bool>(self) -> InvoiceBuilder<DN, HN, TN, CN, SN> {
509                 InvoiceBuilder::<DN, HN, TN, CN, SN> {
510                         currency: self.currency,
511                         amount: self.amount,
512                         si_prefix: self.si_prefix,
513                         timestamp: self.timestamp,
514                         tagged_fields: self.tagged_fields,
515                         error: self.error,
516
517                         phantom_d: core::marker::PhantomData,
518                         phantom_h: core::marker::PhantomData,
519                         phantom_t: core::marker::PhantomData,
520                         phantom_c: core::marker::PhantomData,
521                         phantom_s: core::marker::PhantomData,
522                 }
523         }
524
525         /// Sets the amount in millisatoshis. The optimal SI prefix is chosen automatically.
526         pub fn amount_milli_satoshis(mut self, amount_msat: u64) -> Self {
527                 let amount = amount_msat * 10; // Invoices are denominated in "pico BTC"
528                 let biggest_possible_si_prefix = SiPrefix::values_desc()
529                         .iter()
530                         .find(|prefix| amount % prefix.multiplier() == 0)
531                         .expect("Pico should always match");
532                 self.amount = Some(amount / biggest_possible_si_prefix.multiplier());
533                 self.si_prefix = Some(*biggest_possible_si_prefix);
534                 self
535         }
536
537         /// Sets the payee's public key.
538         pub fn payee_pub_key(mut self, pub_key: PublicKey) -> Self {
539                 self.tagged_fields.push(TaggedField::PayeePubKey(PayeePubKey(pub_key)));
540                 self
541         }
542
543         /// Sets the expiry time, dropping the subsecond part (which is not representable in BOLT 11
544         /// invoices).
545         pub fn expiry_time(mut self, expiry_time: Duration) -> Self {
546                 self.tagged_fields.push(TaggedField::ExpiryTime(ExpiryTime::from_duration(expiry_time)));
547                 self
548         }
549
550         /// Adds a fallback address.
551         pub fn fallback(mut self, fallback: Fallback) -> Self {
552                 self.tagged_fields.push(TaggedField::Fallback(fallback));
553                 self
554         }
555
556         /// Adds a private route.
557         pub fn private_route(mut self, hint: RouteHint) -> Self {
558                 match PrivateRoute::new(hint) {
559                         Ok(r) => self.tagged_fields.push(TaggedField::PrivateRoute(r)),
560                         Err(e) => self.error = Some(e),
561                 }
562                 self
563         }
564 }
565
566 impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, tb::True, C, S> {
567         /// Builds a `RawInvoice` if no `CreationError` occurred while construction any of the fields.
568         pub fn build_raw(self) -> Result<RawInvoice, CreationError> {
569
570                 // If an error occurred at any time before, return it now
571                 if let Some(e) = self.error {
572                         return Err(e);
573                 }
574
575                 let hrp = RawHrp {
576                         currency: self.currency,
577                         raw_amount: self.amount,
578                         si_prefix: self.si_prefix,
579                 };
580
581                 let timestamp = self.timestamp.expect("ensured to be Some(t) by type T");
582
583                 let tagged_fields = self.tagged_fields.into_iter().map(|tf| {
584                         RawTaggedField::KnownSemantics(tf)
585                 }).collect::<Vec<_>>();
586
587                 let data = RawDataPart {
588                         timestamp,
589                         tagged_fields,
590                 };
591
592                 Ok(RawInvoice {
593                         hrp,
594                         data,
595                 })
596         }
597 }
598
599 impl<H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<tb::False, H, T, C, S> {
600         /// Set the description. This function is only available if no description (hash) was set.
601         pub fn description(mut self, description: String) -> InvoiceBuilder<tb::True, H, T, C, S> {
602                 match Description::new(description) {
603                         Ok(d) => self.tagged_fields.push(TaggedField::Description(d)),
604                         Err(e) => self.error = Some(e),
605                 }
606                 self.set_flags()
607         }
608
609         /// Set the description hash. This function is only available if no description (hash) was set.
610         pub fn description_hash(mut self, description_hash: sha256::Hash) -> InvoiceBuilder<tb::True, H, T, C, S> {
611                 self.tagged_fields.push(TaggedField::DescriptionHash(Sha256(description_hash)));
612                 self.set_flags()
613         }
614 }
615
616 impl<D: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, tb::False, T, C, S> {
617         /// Set the payment hash. This function is only available if no payment hash was set.
618         pub fn payment_hash(mut self, hash: sha256::Hash) -> InvoiceBuilder<D, tb::True, T, C, S> {
619                 self.tagged_fields.push(TaggedField::PaymentHash(Sha256(hash)));
620                 self.set_flags()
621         }
622 }
623
624 impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, tb::False, C, S> {
625         /// Sets the timestamp to a specific [`SystemTime`].
626         #[cfg(feature = "std")]
627         pub fn timestamp(mut self, time: SystemTime) -> InvoiceBuilder<D, H, tb::True, C, S> {
628                 match PositiveTimestamp::from_system_time(time) {
629                         Ok(t) => self.timestamp = Some(t),
630                         Err(e) => self.error = Some(e),
631                 }
632
633                 self.set_flags()
634         }
635
636         /// Sets the timestamp to a duration since the Unix epoch, dropping the subsecond part (which
637         /// is not representable in BOLT 11 invoices).
638         pub fn duration_since_epoch(mut self, time: Duration) -> InvoiceBuilder<D, H, tb::True, C, S> {
639                 match PositiveTimestamp::from_duration_since_epoch(time) {
640                         Ok(t) => self.timestamp = Some(t),
641                         Err(e) => self.error = Some(e),
642                 }
643
644                 self.set_flags()
645         }
646
647         /// Sets the timestamp to the current system time.
648         #[cfg(feature = "std")]
649         pub fn current_timestamp(mut self) -> InvoiceBuilder<D, H, tb::True, C, S> {
650                 let now = PositiveTimestamp::from_system_time(SystemTime::now());
651                 self.timestamp = Some(now.expect("for the foreseeable future this shouldn't happen"));
652                 self.set_flags()
653         }
654 }
655
656 impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, T, tb::False, S> {
657         /// Sets `min_final_cltv_expiry_delta`.
658         pub fn min_final_cltv_expiry_delta(mut self, min_final_cltv_expiry_delta: u64) -> InvoiceBuilder<D, H, T, tb::True, S> {
659                 self.tagged_fields.push(TaggedField::MinFinalCltvExpiryDelta(MinFinalCltvExpiryDelta(min_final_cltv_expiry_delta)));
660                 self.set_flags()
661         }
662 }
663
664 impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, T, C, tb::False> {
665         /// Sets the payment secret and relevant features.
666         pub fn payment_secret(mut self, payment_secret: PaymentSecret) -> InvoiceBuilder<D, H, T, C, tb::True> {
667                 let mut features = InvoiceFeatures::empty();
668                 features.set_variable_length_onion_required();
669                 features.set_payment_secret_required();
670                 self.tagged_fields.push(TaggedField::PaymentSecret(payment_secret));
671                 self.tagged_fields.push(TaggedField::Features(features));
672                 self.set_flags()
673         }
674 }
675
676 impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, T, C, tb::True> {
677         /// Sets the `basic_mpp` feature as optional.
678         pub fn basic_mpp(mut self) -> Self {
679                 for field in self.tagged_fields.iter_mut() {
680                         if let TaggedField::Features(f) = field {
681                                 f.set_basic_mpp_optional();
682                         }
683                 }
684                 self
685         }
686 }
687
688 impl InvoiceBuilder<tb::True, tb::True, tb::True, tb::True, tb::True> {
689         /// Builds and signs an invoice using the supplied `sign_function`. This function MAY NOT fail
690         /// and MUST produce a recoverable signature valid for the given hash and if applicable also for
691         /// the included payee public key.
692         pub fn build_signed<F>(self, sign_function: F) -> Result<Invoice, CreationError>
693                 where F: FnOnce(&Message) -> RecoverableSignature
694         {
695                 let invoice = self.try_build_signed::<_, ()>(|hash| {
696                         Ok(sign_function(hash))
697                 });
698
699                 match invoice {
700                         Ok(i) => Ok(i),
701                         Err(SignOrCreationError::CreationError(e)) => Err(e),
702                         Err(SignOrCreationError::SignError(())) => unreachable!(),
703                 }
704         }
705
706         /// Builds and signs an invoice using the supplied `sign_function`. This function MAY fail with
707         /// an error of type `E` and MUST produce a recoverable signature valid for the given hash and
708         /// if applicable also for the included payee public key.
709         pub fn try_build_signed<F, E>(self, sign_function: F) -> Result<Invoice, SignOrCreationError<E>>
710                 where F: FnOnce(&Message) -> Result<RecoverableSignature, E>
711         {
712                 let raw = match self.build_raw() {
713                         Ok(r) => r,
714                         Err(e) => return Err(SignOrCreationError::CreationError(e)),
715                 };
716
717                 let signed = match raw.sign(sign_function) {
718                         Ok(s) => s,
719                         Err(e) => return Err(SignOrCreationError::SignError(e)),
720                 };
721
722                 let invoice = Invoice {
723                         signed_invoice: signed,
724                 };
725
726                 invoice.check_field_counts().expect("should be ensured by type signature of builder");
727                 invoice.check_feature_bits().expect("should be ensured by type signature of builder");
728                 invoice.check_amount().expect("should be ensured by type signature of builder");
729
730                 Ok(invoice)
731         }
732 }
733
734
735 impl SignedRawInvoice {
736         /// Disassembles the `SignedRawInvoice` into its three parts:
737         ///  1. raw invoice
738         ///  2. hash of the raw invoice
739         ///  3. signature
740         pub fn into_parts(self) -> (RawInvoice, [u8; 32], InvoiceSignature) {
741                 (self.raw_invoice, self.hash, self.signature)
742         }
743
744         /// The `RawInvoice` which was signed.
745         pub fn raw_invoice(&self) -> &RawInvoice {
746                 &self.raw_invoice
747         }
748
749         /// The hash of the `RawInvoice` that was signed.
750         pub fn signable_hash(&self) -> &[u8; 32] {
751                 &self.hash
752         }
753
754         /// InvoiceSignature for the invoice.
755         pub fn signature(&self) -> &InvoiceSignature {
756                 &self.signature
757         }
758
759         /// Recovers the public key used for signing the invoice from the recoverable signature.
760         pub fn recover_payee_pub_key(&self) -> Result<PayeePubKey, secp256k1::Error> {
761                 let hash = Message::from_slice(&self.hash[..])
762                         .expect("Hash is 32 bytes long, same as MESSAGE_SIZE");
763
764                 Ok(PayeePubKey(Secp256k1::new().recover_ecdsa(
765                         &hash,
766                         &self.signature
767                 )?))
768         }
769
770         /// Checks if the signature is valid for the included payee public key or if none exists if it's
771         /// valid for the recovered signature (which should always be true?).
772         pub fn check_signature(&self) -> bool {
773                 let included_pub_key = self.raw_invoice.payee_pub_key();
774
775                 let mut recovered_pub_key = Option::None;
776                 if recovered_pub_key.is_none() {
777                         let recovered = match self.recover_payee_pub_key() {
778                                 Ok(pk) => pk,
779                                 Err(_) => return false,
780                         };
781                         recovered_pub_key = Some(recovered);
782                 }
783
784                 let pub_key = included_pub_key.or(recovered_pub_key.as_ref())
785                         .expect("One is always present");
786
787                 let hash = Message::from_slice(&self.hash[..])
788                         .expect("Hash is 32 bytes long, same as MESSAGE_SIZE");
789
790                 let secp_context = Secp256k1::new();
791                 let verification_result = secp_context.verify_ecdsa(
792                         &hash,
793                         &self.signature.to_standard(),
794                         pub_key
795                 );
796
797                 match verification_result {
798                         Ok(()) => true,
799                         Err(_) => false,
800                 }
801         }
802 }
803
804 /// Finds the first element of an enum stream of a given variant and extracts one member of the
805 /// variant. If no element was found `None` gets returned.
806 ///
807 /// The following example would extract the first B.
808 ///
809 /// ```ignore
810 /// enum Enum {
811 ///     A(u8),
812 ///     B(u16)
813 /// }
814 ///
815 /// let elements = vec![Enum::A(1), Enum::A(2), Enum::B(3), Enum::A(4)];
816 ///
817 /// assert_eq!(find_extract!(elements.iter(), Enum::B(x), x), Some(3u16));
818 /// ```
819 macro_rules! find_extract {
820         ($iter:expr, $enm:pat, $enm_var:ident) => {
821                 find_all_extract!($iter, $enm, $enm_var).next()
822         };
823 }
824
825 /// Finds the all elements of an enum stream of a given variant and extracts one member of the
826 /// variant through an iterator.
827 ///
828 /// The following example would extract all A.
829 ///
830 /// ```ignore
831 /// enum Enum {
832 ///     A(u8),
833 ///     B(u16)
834 /// }
835 ///
836 /// let elements = vec![Enum::A(1), Enum::A(2), Enum::B(3), Enum::A(4)];
837 ///
838 /// assert_eq!(
839 ///     find_all_extract!(elements.iter(), Enum::A(x), x).collect::<Vec<u8>>(),
840 ///     vec![1u8, 2u8, 4u8]
841 /// );
842 /// ```
843 macro_rules! find_all_extract {
844         ($iter:expr, $enm:pat, $enm_var:ident) => {
845                 $iter.filter_map(|tf| match *tf {
846                         $enm => Some($enm_var),
847                         _ => None,
848                 })
849         };
850 }
851
852 #[allow(missing_docs)]
853 impl RawInvoice {
854         /// Hash the HRP as bytes and signatureless data part.
855         fn hash_from_parts(hrp_bytes: &[u8], data_without_signature: &[u5]) -> [u8; 32] {
856                 let preimage = construct_invoice_preimage(hrp_bytes, data_without_signature);
857                 let mut hash: [u8; 32] = Default::default();
858                 hash.copy_from_slice(&sha256::Hash::hash(&preimage)[..]);
859                 hash
860         }
861
862         /// Calculate the hash of the encoded `RawInvoice` which should be signed.
863         pub fn signable_hash(&self) -> [u8; 32] {
864                 use bech32::ToBase32;
865
866                 RawInvoice::hash_from_parts(
867                         self.hrp.to_string().as_bytes(),
868                         &self.data.to_base32()
869                 )
870         }
871
872         /// Signs the invoice using the supplied `sign_function`. This function MAY fail with an error
873         /// of type `E`. Since the signature of a `SignedRawInvoice` is not required to be valid there
874         /// are no constraints regarding the validity of the produced signature.
875         ///
876         /// (C-not exported) As we don't currently support passing function pointers into methods
877         /// explicitly.
878         pub fn sign<F, E>(self, sign_method: F) -> Result<SignedRawInvoice, E>
879                 where F: FnOnce(&Message) -> Result<RecoverableSignature, E>
880         {
881                 let raw_hash = self.signable_hash();
882                 let hash = Message::from_slice(&raw_hash[..])
883                         .expect("Hash is 32 bytes long, same as MESSAGE_SIZE");
884                 let signature = sign_method(&hash)?;
885
886                 Ok(SignedRawInvoice {
887                         raw_invoice: self,
888                         hash: raw_hash,
889                         signature: InvoiceSignature(signature),
890                 })
891         }
892
893         /// Returns an iterator over all tagged fields with known semantics.
894         ///
895         /// (C-not exported) As there is not yet a manual mapping for a FilterMap
896         pub fn known_tagged_fields(&self)
897                 -> FilterMap<Iter<RawTaggedField>, fn(&RawTaggedField) -> Option<&TaggedField>>
898         {
899                 // For 1.14.0 compatibility: closures' types can't be written an fn()->() in the
900                 // function's type signature.
901                 // TODO: refactor once impl Trait is available
902                 fn match_raw(raw: &RawTaggedField) -> Option<&TaggedField> {
903                         match *raw {
904                                 RawTaggedField::KnownSemantics(ref tf) => Some(tf),
905                                 _ => None,
906                         }
907                 }
908
909                 self.data.tagged_fields.iter().filter_map(match_raw )
910         }
911
912         pub fn payment_hash(&self) -> Option<&Sha256> {
913                 find_extract!(self.known_tagged_fields(), TaggedField::PaymentHash(ref x), x)
914         }
915
916         pub fn description(&self) -> Option<&Description> {
917                 find_extract!(self.known_tagged_fields(), TaggedField::Description(ref x), x)
918         }
919
920         pub fn payee_pub_key(&self) -> Option<&PayeePubKey> {
921                 find_extract!(self.known_tagged_fields(), TaggedField::PayeePubKey(ref x), x)
922         }
923
924         pub fn description_hash(&self) -> Option<&Sha256> {
925                 find_extract!(self.known_tagged_fields(), TaggedField::DescriptionHash(ref x), x)
926         }
927
928         pub fn expiry_time(&self) -> Option<&ExpiryTime> {
929                 find_extract!(self.known_tagged_fields(), TaggedField::ExpiryTime(ref x), x)
930         }
931
932         pub fn min_final_cltv_expiry_delta(&self) -> Option<&MinFinalCltvExpiryDelta> {
933                 find_extract!(self.known_tagged_fields(), TaggedField::MinFinalCltvExpiryDelta(ref x), x)
934         }
935
936         pub fn payment_secret(&self) -> Option<&PaymentSecret> {
937                 find_extract!(self.known_tagged_fields(), TaggedField::PaymentSecret(ref x), x)
938         }
939
940         pub fn features(&self) -> Option<&InvoiceFeatures> {
941                 find_extract!(self.known_tagged_fields(), TaggedField::Features(ref x), x)
942         }
943
944         /// (C-not exported) as we don't support Vec<&NonOpaqueType>
945         pub fn fallbacks(&self) -> Vec<&Fallback> {
946                 find_all_extract!(self.known_tagged_fields(), TaggedField::Fallback(ref x), x).collect()
947         }
948
949         pub fn private_routes(&self) -> Vec<&PrivateRoute> {
950                 find_all_extract!(self.known_tagged_fields(), TaggedField::PrivateRoute(ref x), x).collect()
951         }
952
953         pub fn amount_pico_btc(&self) -> Option<u64> {
954                 self.hrp.raw_amount.map(|v| {
955                         v * self.hrp.si_prefix.as_ref().map_or(1_000_000_000_000, |si| { si.multiplier() })
956                 })
957         }
958
959         pub fn currency(&self) -> Currency {
960                 self.hrp.currency.clone()
961         }
962 }
963
964 impl PositiveTimestamp {
965         /// Creates a `PositiveTimestamp` from a Unix timestamp in the range `0..=MAX_TIMESTAMP`.
966         ///
967         /// Otherwise, returns a [`CreationError::TimestampOutOfBounds`].
968         pub fn from_unix_timestamp(unix_seconds: u64) -> Result<Self, CreationError> {
969                 if unix_seconds <= MAX_TIMESTAMP {
970                         Ok(Self(Duration::from_secs(unix_seconds)))
971                 } else {
972                         Err(CreationError::TimestampOutOfBounds)
973                 }
974         }
975
976         /// Creates a `PositiveTimestamp` from a [`SystemTime`] with a corresponding Unix timestamp in
977         /// the range `0..=MAX_TIMESTAMP`.
978         ///
979         /// Note that the subsecond part is dropped as it is not representable in BOLT 11 invoices.
980         ///
981         /// Otherwise, returns a [`CreationError::TimestampOutOfBounds`].
982         #[cfg(feature = "std")]
983         pub fn from_system_time(time: SystemTime) -> Result<Self, CreationError> {
984                 time.duration_since(SystemTime::UNIX_EPOCH)
985                         .map(Self::from_duration_since_epoch)
986                         .unwrap_or(Err(CreationError::TimestampOutOfBounds))
987         }
988
989         /// Creates a `PositiveTimestamp` from a [`Duration`] since the Unix epoch in the range
990         /// `0..=MAX_TIMESTAMP`.
991         ///
992         /// Note that the subsecond part is dropped as it is not representable in BOLT 11 invoices.
993         ///
994         /// Otherwise, returns a [`CreationError::TimestampOutOfBounds`].
995         pub fn from_duration_since_epoch(duration: Duration) -> Result<Self, CreationError> {
996                 Self::from_unix_timestamp(duration.as_secs())
997         }
998
999         /// Returns the Unix timestamp representing the stored time
1000         pub fn as_unix_timestamp(&self) -> u64 {
1001                 self.0.as_secs()
1002         }
1003
1004         /// Returns the duration of the stored time since the Unix epoch
1005         pub fn as_duration_since_epoch(&self) -> Duration {
1006                 self.0
1007         }
1008
1009         /// Returns the [`SystemTime`] representing the stored time
1010         #[cfg(feature = "std")]
1011         pub fn as_time(&self) -> SystemTime {
1012                 SystemTime::UNIX_EPOCH + self.0
1013         }
1014 }
1015
1016 #[cfg(feature = "std")]
1017 impl From<PositiveTimestamp> for SystemTime {
1018         fn from(val: PositiveTimestamp) -> Self {
1019                 SystemTime::UNIX_EPOCH + val.0
1020         }
1021 }
1022
1023 impl Invoice {
1024         /// Transform the `Invoice` into it's unchecked version
1025         pub fn into_signed_raw(self) -> SignedRawInvoice {
1026                 self.signed_invoice
1027         }
1028
1029         /// Check that all mandatory fields are present
1030         fn check_field_counts(&self) -> Result<(), SemanticError> {
1031                 // "A writer MUST include exactly one p field […]."
1032                 let payment_hash_cnt = self.tagged_fields().filter(|&tf| match *tf {
1033                         TaggedField::PaymentHash(_) => true,
1034                         _ => false,
1035                 }).count();
1036                 if payment_hash_cnt < 1 {
1037                         return Err(SemanticError::NoPaymentHash);
1038                 } else if payment_hash_cnt > 1 {
1039                         return Err(SemanticError::MultiplePaymentHashes);
1040                 }
1041
1042                 // "A writer MUST include either exactly one d or exactly one h field."
1043                 let description_cnt = self.tagged_fields().filter(|&tf| match *tf {
1044                         TaggedField::Description(_) | TaggedField::DescriptionHash(_) => true,
1045                         _ => false,
1046                 }).count();
1047                 if  description_cnt < 1 {
1048                         return Err(SemanticError::NoDescription);
1049                 } else if description_cnt > 1 {
1050                         return  Err(SemanticError::MultipleDescriptions);
1051                 }
1052
1053                 self.check_payment_secret()?;
1054
1055                 Ok(())
1056         }
1057
1058         /// Checks that there is exactly one payment secret field
1059         fn check_payment_secret(&self) -> Result<(), SemanticError> {
1060                 // "A writer MUST include exactly one `s` field."
1061                 let payment_secret_count = self.tagged_fields().filter(|&tf| match *tf {
1062                         TaggedField::PaymentSecret(_) => true,
1063                         _ => false,
1064                 }).count();
1065                 if payment_secret_count < 1 {
1066                         return Err(SemanticError::NoPaymentSecret);
1067                 } else if payment_secret_count > 1 {
1068                         return Err(SemanticError::MultiplePaymentSecrets);
1069                 }
1070
1071                 Ok(())
1072         }
1073
1074         /// Check that amount is a whole number of millisatoshis
1075         fn check_amount(&self) -> Result<(), SemanticError> {
1076                 if let Some(amount_pico_btc) = self.amount_pico_btc() {
1077                         if amount_pico_btc % 10 != 0 {
1078                                 return Err(SemanticError::ImpreciseAmount);
1079                         }
1080                 }
1081                 Ok(())
1082         }
1083
1084         /// Check that feature bits are set as required
1085         fn check_feature_bits(&self) -> Result<(), SemanticError> {
1086                 self.check_payment_secret()?;
1087
1088                 // "A writer MUST set an s field if and only if the payment_secret feature is set."
1089                 // (this requirement has been since removed, and we now require the payment secret
1090                 // feature bit always).
1091                 let features = self.tagged_fields().find(|&tf| match *tf {
1092                         TaggedField::Features(_) => true,
1093                         _ => false,
1094                 });
1095                 match features {
1096                         None => Err(SemanticError::InvalidFeatures),
1097                         Some(TaggedField::Features(features)) => {
1098                                 if features.requires_unknown_bits() {
1099                                         Err(SemanticError::InvalidFeatures)
1100                                 } else if !features.supports_payment_secret() {
1101                                         Err(SemanticError::InvalidFeatures)
1102                                 } else {
1103                                         Ok(())
1104                                 }
1105                         },
1106                         Some(_) => unreachable!(),
1107                 }
1108         }
1109
1110         /// Check that the invoice is signed correctly and that key recovery works
1111         pub fn check_signature(&self) -> Result<(), SemanticError> {
1112                 match self.signed_invoice.recover_payee_pub_key() {
1113                         Err(secp256k1::Error::InvalidRecoveryId) =>
1114                                 return Err(SemanticError::InvalidRecoveryId),
1115                         Err(secp256k1::Error::InvalidSignature) =>
1116                                 return Err(SemanticError::InvalidSignature),
1117                         Err(e) => panic!("no other error may occur, got {:?}", e),
1118                         Ok(_) => {},
1119                 }
1120
1121                 if !self.signed_invoice.check_signature() {
1122                         return Err(SemanticError::InvalidSignature);
1123                 }
1124
1125                 Ok(())
1126         }
1127
1128         /// Constructs an `Invoice` from a `SignedRawInvoice` by checking all its invariants.
1129         /// ```
1130         /// use lightning_invoice::*;
1131         ///
1132         /// let invoice = "lnbc100p1psj9jhxdqud3jxktt5w46x7unfv9kz6mn0v3jsnp4q0d3p2sfluzdx45tqcs\
1133         /// h2pu5qc7lgq0xs578ngs6s0s68ua4h7cvspp5q6rmq35js88zp5dvwrv9m459tnk2zunwj5jalqtyxqulh0l\
1134         /// 5gflssp5nf55ny5gcrfl30xuhzj3nphgj27rstekmr9fw3ny5989s300gyus9qyysgqcqpcrzjqw2sxwe993\
1135         /// h5pcm4dxzpvttgza8zhkqxpgffcrf5v25nwpr3cmfg7z54kuqq8rgqqqqqqqq2qqqqq9qq9qrzjqd0ylaqcl\
1136         /// j9424x9m8h2vcukcgnm6s56xfgu3j78zyqzhgs4hlpzvznlugqq9vsqqqqqqqlgqqqqqeqq9qrzjqwldmj9d\
1137         /// ha74df76zhx6l9we0vjdquygcdt3kssupehe64g6yyp5yz5rhuqqwccqqyqqqqlgqqqqjcqq9qrzjqf9e58a\
1138         /// guqr0rcun0ajlvmzq3ek63cw2w282gv3z5uupmuwvgjtq2z55qsqqg6qqqyqqqrtnqqqzq3cqygrzjqvphms\
1139         /// ywntrrhqjcraumvc4y6r8v4z5v593trte429v4hredj7ms5z52usqq9ngqqqqqqqlgqqqqqqgq9qrzjq2v0v\
1140         /// p62g49p7569ev48cmulecsxe59lvaw3wlxm7r982zxa9zzj7z5l0cqqxusqqyqqqqlgqqqqqzsqygarl9fh3\
1141         /// 8s0gyuxjjgux34w75dnc6xp2l35j7es3jd4ugt3lu0xzre26yg5m7ke54n2d5sym4xcmxtl8238xxvw5h5h5\
1142         /// j5r6drg6k6zcqj0fcwg";
1143         ///
1144         /// let signed = invoice.parse::<SignedRawInvoice>().unwrap();
1145         ///
1146         /// assert!(Invoice::from_signed(signed).is_ok());
1147         /// ```
1148         pub fn from_signed(signed_invoice: SignedRawInvoice) -> Result<Self, SemanticError> {
1149                 let invoice = Invoice {
1150                         signed_invoice,
1151                 };
1152                 invoice.check_field_counts()?;
1153                 invoice.check_feature_bits()?;
1154                 invoice.check_signature()?;
1155                 invoice.check_amount()?;
1156
1157                 Ok(invoice)
1158         }
1159
1160         /// Returns the `Invoice`'s timestamp (should equal its creation time)
1161         #[cfg(feature = "std")]
1162         pub fn timestamp(&self) -> SystemTime {
1163                 self.signed_invoice.raw_invoice().data.timestamp.as_time()
1164         }
1165
1166         /// Returns the `Invoice`'s timestamp as a duration since the Unix epoch
1167         pub fn duration_since_epoch(&self) -> Duration {
1168                 self.signed_invoice.raw_invoice().data.timestamp.0
1169         }
1170
1171         /// Returns an iterator over all tagged fields of this Invoice.
1172         ///
1173         /// (C-not exported) As there is not yet a manual mapping for a FilterMap
1174         pub fn tagged_fields(&self)
1175                 -> FilterMap<Iter<RawTaggedField>, fn(&RawTaggedField) -> Option<&TaggedField>> {
1176                 self.signed_invoice.raw_invoice().known_tagged_fields()
1177         }
1178
1179         /// Returns the hash to which we will receive the preimage on completion of the payment
1180         pub fn payment_hash(&self) -> &sha256::Hash {
1181                 &self.signed_invoice.payment_hash().expect("checked by constructor").0
1182         }
1183
1184         /// Return the description or a hash of it for longer ones
1185         ///
1186         /// (C-not exported) because we don't yet export InvoiceDescription
1187         pub fn description(&self) -> InvoiceDescription {
1188                 if let Some(direct) = self.signed_invoice.description() {
1189                         return InvoiceDescription::Direct(direct);
1190                 } else if let Some(hash) = self.signed_invoice.description_hash() {
1191                         return InvoiceDescription::Hash(hash);
1192                 }
1193                 unreachable!("ensured by constructor");
1194         }
1195
1196         /// Get the payee's public key if one was included in the invoice
1197         pub fn payee_pub_key(&self) -> Option<&PublicKey> {
1198                 self.signed_invoice.payee_pub_key().map(|x| &x.0)
1199         }
1200
1201         /// Get the payment secret if one was included in the invoice
1202         pub fn payment_secret(&self) -> &PaymentSecret {
1203                 self.signed_invoice.payment_secret().expect("was checked by constructor")
1204         }
1205
1206         /// Get the invoice features if they were included in the invoice
1207         pub fn features(&self) -> Option<&InvoiceFeatures> {
1208                 self.signed_invoice.features()
1209         }
1210
1211         /// Recover the payee's public key (only to be used if none was included in the invoice)
1212         pub fn recover_payee_pub_key(&self) -> PublicKey {
1213                 self.signed_invoice.recover_payee_pub_key().expect("was checked by constructor").0
1214         }
1215
1216         /// Returns the Duration since the Unix epoch at which the invoice expires.
1217         /// Returning None if overflow occurred.
1218         pub fn expires_at(&self) -> Option<Duration> {
1219                 self.duration_since_epoch().checked_add(self.expiry_time())
1220         }
1221
1222         /// Returns the invoice's expiry time, if present, otherwise [`DEFAULT_EXPIRY_TIME`].
1223         pub fn expiry_time(&self) -> Duration {
1224                 self.signed_invoice.expiry_time()
1225                         .map(|x| x.0)
1226                         .unwrap_or(Duration::from_secs(DEFAULT_EXPIRY_TIME))
1227         }
1228
1229         /// Returns whether the invoice has expired.
1230         #[cfg(feature = "std")]
1231         pub fn is_expired(&self) -> bool {
1232                 Self::is_expired_from_epoch(&self.timestamp(), self.expiry_time())
1233         }
1234
1235         /// Returns whether the expiry time from the given epoch has passed.
1236         #[cfg(feature = "std")]
1237         pub(crate) fn is_expired_from_epoch(epoch: &SystemTime, expiry_time: Duration) -> bool {
1238                 match epoch.elapsed() {
1239                         Ok(elapsed) => elapsed > expiry_time,
1240                         Err(_) => false,
1241                 }
1242         }
1243
1244         /// Returns the Duration remaining until the invoice expires.
1245         #[cfg(feature = "std")]
1246         pub fn duration_until_expiry(&self) -> Duration {
1247                 SystemTime::now().duration_since(SystemTime::UNIX_EPOCH)
1248                         .map(|now| self.expiration_remaining_from_epoch(now))
1249                         .unwrap_or(Duration::from_nanos(0))
1250         }
1251
1252         /// Returns the Duration remaining until the invoice expires given the current time.
1253         /// `time` is the timestamp as a duration since the Unix epoch.
1254         pub fn expiration_remaining_from_epoch(&self, time: Duration) -> Duration {
1255                 self.expires_at().map(|x| x.checked_sub(time)).flatten().unwrap_or(Duration::from_nanos(0))
1256         }
1257
1258         /// Returns whether the expiry time would pass at the given point in time.
1259         /// `at_time` is the timestamp as a duration since the Unix epoch.
1260         pub fn would_expire(&self, at_time: Duration) -> bool {
1261                 self.duration_since_epoch()
1262                         .checked_add(self.expiry_time())
1263                         .unwrap_or_else(|| Duration::new(u64::max_value(), 1_000_000_000 - 1)) < at_time
1264         }
1265
1266         /// Returns the invoice's `min_final_cltv_expiry_delta` time, if present, otherwise
1267         /// [`DEFAULT_MIN_FINAL_CLTV_EXPIRY_DELTA`].
1268         pub fn min_final_cltv_expiry_delta(&self) -> u64 {
1269                 self.signed_invoice.min_final_cltv_expiry_delta()
1270                         .map(|x| x.0)
1271                         .unwrap_or(DEFAULT_MIN_FINAL_CLTV_EXPIRY_DELTA)
1272         }
1273
1274         /// Returns a list of all fallback addresses
1275         ///
1276         /// (C-not exported) as we don't support Vec<&NonOpaqueType>
1277         pub fn fallbacks(&self) -> Vec<&Fallback> {
1278                 self.signed_invoice.fallbacks()
1279         }
1280
1281         /// Returns a list of all routes included in the invoice
1282         pub fn private_routes(&self) -> Vec<&PrivateRoute> {
1283                 self.signed_invoice.private_routes()
1284         }
1285
1286         /// Returns a list of all routes included in the invoice as the underlying hints
1287         pub fn route_hints(&self) -> Vec<RouteHint> {
1288                 find_all_extract!(
1289                         self.signed_invoice.known_tagged_fields(), TaggedField::PrivateRoute(ref x), x
1290                 ).map(|route| (**route).clone()).collect()
1291         }
1292
1293         /// Returns the currency for which the invoice was issued
1294         pub fn currency(&self) -> Currency {
1295                 self.signed_invoice.currency()
1296         }
1297
1298         /// Returns the amount if specified in the invoice as millisatoshis.
1299         pub fn amount_milli_satoshis(&self) -> Option<u64> {
1300                 self.signed_invoice.amount_pico_btc().map(|v| v / 10)
1301         }
1302
1303         /// Returns the amount if specified in the invoice as pico BTC.
1304         fn amount_pico_btc(&self) -> Option<u64> {
1305                 self.signed_invoice.amount_pico_btc()
1306         }
1307 }
1308
1309 impl From<TaggedField> for RawTaggedField {
1310         fn from(tf: TaggedField) -> Self {
1311                 RawTaggedField::KnownSemantics(tf)
1312         }
1313 }
1314
1315 impl TaggedField {
1316         /// Numeric representation of the field's tag
1317         pub fn tag(&self) -> u5 {
1318                 let tag = match *self {
1319                         TaggedField::PaymentHash(_) => constants::TAG_PAYMENT_HASH,
1320                         TaggedField::Description(_) => constants::TAG_DESCRIPTION,
1321                         TaggedField::PayeePubKey(_) => constants::TAG_PAYEE_PUB_KEY,
1322                         TaggedField::DescriptionHash(_) => constants::TAG_DESCRIPTION_HASH,
1323                         TaggedField::ExpiryTime(_) => constants::TAG_EXPIRY_TIME,
1324                         TaggedField::MinFinalCltvExpiryDelta(_) => constants::TAG_MIN_FINAL_CLTV_EXPIRY_DELTA,
1325                         TaggedField::Fallback(_) => constants::TAG_FALLBACK,
1326                         TaggedField::PrivateRoute(_) => constants::TAG_PRIVATE_ROUTE,
1327                         TaggedField::PaymentSecret(_) => constants::TAG_PAYMENT_SECRET,
1328                         TaggedField::Features(_) => constants::TAG_FEATURES,
1329                 };
1330
1331                 u5::try_from_u8(tag).expect("all tags defined are <32")
1332         }
1333 }
1334
1335 impl Description {
1336
1337         /// Creates a new `Description` if `description` is at most 1023 __bytes__ long,
1338         /// returns `CreationError::DescriptionTooLong` otherwise
1339         ///
1340         /// Please note that single characters may use more than one byte due to UTF8 encoding.
1341         pub fn new(description: String) -> Result<Description, CreationError> {
1342                 if description.len() > 639 {
1343                         Err(CreationError::DescriptionTooLong)
1344                 } else {
1345                         Ok(Description(description))
1346                 }
1347         }
1348
1349         /// Returns the underlying description `String`
1350         pub fn into_inner(self) -> String {
1351                 self.0
1352         }
1353 }
1354
1355 impl From<Description> for String {
1356         fn from(val: Description) -> Self {
1357                 val.into_inner()
1358         }
1359 }
1360
1361 impl Deref for Description {
1362         type Target = str;
1363
1364         fn deref(&self) -> &str {
1365                 &self.0
1366         }
1367 }
1368
1369 impl From<PublicKey> for PayeePubKey {
1370         fn from(pk: PublicKey) -> Self {
1371                 PayeePubKey(pk)
1372         }
1373 }
1374
1375 impl Deref for PayeePubKey {
1376         type Target = PublicKey;
1377
1378         fn deref(&self) -> &PublicKey {
1379                 &self.0
1380         }
1381 }
1382
1383 impl ExpiryTime {
1384         /// Construct an `ExpiryTime` from seconds.
1385         pub fn from_seconds(seconds: u64) -> ExpiryTime {
1386                 ExpiryTime(Duration::from_secs(seconds))
1387         }
1388
1389         /// Construct an `ExpiryTime` from a `Duration`, dropping the sub-second part.
1390         pub fn from_duration(duration: Duration) -> ExpiryTime {
1391                 Self::from_seconds(duration.as_secs())
1392         }
1393
1394         /// Returns the expiry time in seconds
1395         pub fn as_seconds(&self) -> u64 {
1396                 self.0.as_secs()
1397         }
1398
1399         /// Returns a reference to the underlying `Duration` (=expiry time)
1400         pub fn as_duration(&self) -> &Duration {
1401                 &self.0
1402         }
1403 }
1404
1405 impl PrivateRoute {
1406         /// Creates a new (partial) route from a list of hops
1407         pub fn new(hops: RouteHint) -> Result<PrivateRoute, CreationError> {
1408                 if hops.0.len() <= 12 {
1409                         Ok(PrivateRoute(hops))
1410                 } else {
1411                         Err(CreationError::RouteTooLong)
1412                 }
1413         }
1414
1415         /// Returns the underlying list of hops
1416         pub fn into_inner(self) -> RouteHint {
1417                 self.0
1418         }
1419 }
1420
1421 impl From<PrivateRoute> for RouteHint {
1422         fn from(val: PrivateRoute) -> Self {
1423                 val.into_inner()
1424         }
1425 }
1426
1427 impl Deref for PrivateRoute {
1428         type Target = RouteHint;
1429
1430         fn deref(&self) -> &RouteHint {
1431                 &self.0
1432         }
1433 }
1434
1435 impl Deref for InvoiceSignature {
1436         type Target = RecoverableSignature;
1437
1438         fn deref(&self) -> &RecoverableSignature {
1439                 &self.0
1440         }
1441 }
1442
1443 impl Deref for SignedRawInvoice {
1444         type Target = RawInvoice;
1445
1446         fn deref(&self) -> &RawInvoice {
1447                 &self.raw_invoice
1448         }
1449 }
1450
1451 /// Errors that may occur when constructing a new `RawInvoice` or `Invoice`
1452 #[derive(Eq, PartialEq, Debug, Clone)]
1453 pub enum CreationError {
1454         /// The supplied description string was longer than 639 __bytes__ (see [`Description::new(…)`](./struct.Description.html#method.new))
1455         DescriptionTooLong,
1456
1457         /// The specified route has too many hops and can't be encoded
1458         RouteTooLong,
1459
1460         /// The Unix timestamp of the supplied date is less than zero or greater than 35-bits
1461         TimestampOutOfBounds,
1462
1463         /// The supplied millisatoshi amount was greater than the total bitcoin supply.
1464         InvalidAmount,
1465
1466         /// Route hints were required for this invoice and were missing. Applies to
1467         /// [phantom invoices].
1468         ///
1469         /// [phantom invoices]: crate::utils::create_phantom_invoice
1470         MissingRouteHints,
1471
1472         /// The provided `min_final_cltv_expiry_delta` was less than [`MIN_FINAL_CLTV_EXPIRY_DELTA`].
1473         ///
1474         /// [`MIN_FINAL_CLTV_EXPIRY_DELTA`]: lightning::ln::channelmanager::MIN_FINAL_CLTV_EXPIRY_DELTA
1475         MinFinalCltvExpiryDeltaTooShort,
1476 }
1477
1478 impl Display for CreationError {
1479         fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
1480                 match self {
1481                         CreationError::DescriptionTooLong => f.write_str("The supplied description string was longer than 639 bytes"),
1482                         CreationError::RouteTooLong => f.write_str("The specified route has too many hops and can't be encoded"),
1483                         CreationError::TimestampOutOfBounds => f.write_str("The Unix timestamp of the supplied date is less than zero or greater than 35-bits"),
1484                         CreationError::InvalidAmount => f.write_str("The supplied millisatoshi amount was greater than the total bitcoin supply"),
1485                         CreationError::MissingRouteHints => f.write_str("The invoice required route hints and they weren't provided"),
1486                         CreationError::MinFinalCltvExpiryDeltaTooShort => f.write_str(
1487                                 "The supplied final CLTV expiry delta was less than LDK's `MIN_FINAL_CLTV_EXPIRY_DELTA`"),
1488                 }
1489         }
1490 }
1491
1492 #[cfg(feature = "std")]
1493 impl std::error::Error for CreationError { }
1494
1495 /// Errors that may occur when converting a `RawInvoice` to an `Invoice`. They relate to the
1496 /// requirements sections in BOLT #11
1497 #[derive(Eq, PartialEq, Debug, Clone)]
1498 pub enum SemanticError {
1499         /// The invoice is missing the mandatory payment hash
1500         NoPaymentHash,
1501
1502         /// The invoice has multiple payment hashes which isn't allowed
1503         MultiplePaymentHashes,
1504
1505         /// No description or description hash are part of the invoice
1506         NoDescription,
1507
1508         /// The invoice contains multiple descriptions and/or description hashes which isn't allowed
1509         MultipleDescriptions,
1510
1511         /// The invoice is missing the mandatory payment secret, which all modern lightning nodes
1512         /// should provide.
1513         NoPaymentSecret,
1514
1515         /// The invoice contains multiple payment secrets
1516         MultiplePaymentSecrets,
1517
1518         /// The invoice's features are invalid
1519         InvalidFeatures,
1520
1521         /// The recovery id doesn't fit the signature/pub key
1522         InvalidRecoveryId,
1523
1524         /// The invoice's signature is invalid
1525         InvalidSignature,
1526
1527         /// The invoice's amount was not a whole number of millisatoshis
1528         ImpreciseAmount,
1529 }
1530
1531 impl Display for SemanticError {
1532         fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
1533                 match self {
1534                         SemanticError::NoPaymentHash => f.write_str("The invoice is missing the mandatory payment hash"),
1535                         SemanticError::MultiplePaymentHashes => f.write_str("The invoice has multiple payment hashes which isn't allowed"),
1536                         SemanticError::NoDescription => f.write_str("No description or description hash are part of the invoice"),
1537                         SemanticError::MultipleDescriptions => f.write_str("The invoice contains multiple descriptions and/or description hashes which isn't allowed"),
1538                         SemanticError::NoPaymentSecret => f.write_str("The invoice is missing the mandatory payment secret"),
1539                         SemanticError::MultiplePaymentSecrets => f.write_str("The invoice contains multiple payment secrets"),
1540                         SemanticError::InvalidFeatures => f.write_str("The invoice's features are invalid"),
1541                         SemanticError::InvalidRecoveryId => f.write_str("The recovery id doesn't fit the signature/pub key"),
1542                         SemanticError::InvalidSignature => f.write_str("The invoice's signature is invalid"),
1543                         SemanticError::ImpreciseAmount => f.write_str("The invoice's amount was not a whole number of millisatoshis"),
1544                 }
1545         }
1546 }
1547
1548 #[cfg(feature = "std")]
1549 impl std::error::Error for SemanticError { }
1550
1551 /// When signing using a fallible method either an user-supplied `SignError` or a `CreationError`
1552 /// may occur.
1553 #[derive(Eq, PartialEq, Debug, Clone)]
1554 pub enum SignOrCreationError<S = ()> {
1555         /// An error occurred during signing
1556         SignError(S),
1557
1558         /// An error occurred while building the transaction
1559         CreationError(CreationError),
1560 }
1561
1562 impl<S> Display for SignOrCreationError<S> {
1563         fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
1564                 match self {
1565                         SignOrCreationError::SignError(_) => f.write_str("An error occurred during signing"),
1566                         SignOrCreationError::CreationError(err) => err.fmt(f),
1567                 }
1568         }
1569 }
1570
1571 #[cfg(feature = "serde")]
1572 impl Serialize for Invoice {
1573         fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer {
1574                 serializer.serialize_str(self.to_string().as_str())
1575         }
1576 }
1577 #[cfg(feature = "serde")]
1578 impl<'de> Deserialize<'de> for Invoice {
1579         fn deserialize<D>(deserializer: D) -> Result<Invoice, D::Error> where D: Deserializer<'de> {
1580                 let bolt11 = String::deserialize(deserializer)?
1581                         .parse::<Invoice>()
1582                         .map_err(|e| D::Error::custom(format!("{:?}", e)))?;
1583
1584                 Ok(bolt11)
1585         }
1586 }
1587
1588 #[cfg(test)]
1589 mod test {
1590         use bitcoin_hashes::hex::FromHex;
1591         use bitcoin_hashes::sha256;
1592
1593         #[test]
1594         fn test_system_time_bounds_assumptions() {
1595                 assert_eq!(
1596                         crate::PositiveTimestamp::from_unix_timestamp(crate::MAX_TIMESTAMP + 1),
1597                         Err(crate::CreationError::TimestampOutOfBounds)
1598                 );
1599         }
1600
1601         #[test]
1602         fn test_calc_invoice_hash() {
1603                 use crate::{RawInvoice, RawHrp, RawDataPart, Currency, PositiveTimestamp};
1604                 use crate::TaggedField::*;
1605
1606                 let invoice = RawInvoice {
1607                         hrp: RawHrp {
1608                                 currency: Currency::Bitcoin,
1609                                 raw_amount: None,
1610                                 si_prefix: None,
1611                         },
1612                         data: RawDataPart {
1613                                 timestamp: PositiveTimestamp::from_unix_timestamp(1496314658).unwrap(),
1614                                 tagged_fields: vec![
1615                                         PaymentHash(crate::Sha256(sha256::Hash::from_hex(
1616                                                 "0001020304050607080900010203040506070809000102030405060708090102"
1617                                         ).unwrap())).into(),
1618                                         Description(crate::Description::new(
1619                                                 "Please consider supporting this project".to_owned()
1620                                         ).unwrap()).into(),
1621                                 ],
1622                         },
1623                 };
1624
1625                 let expected_hash = [
1626                         0xc3, 0xd4, 0xe8, 0x3f, 0x64, 0x6f, 0xa7, 0x9a, 0x39, 0x3d, 0x75, 0x27, 0x7b, 0x1d,
1627                         0x85, 0x8d, 0xb1, 0xd1, 0xf7, 0xab, 0x71, 0x37, 0xdc, 0xb7, 0x83, 0x5d, 0xb2, 0xec,
1628                         0xd5, 0x18, 0xe1, 0xc9
1629                 ];
1630
1631                 assert_eq!(invoice.signable_hash(), expected_hash)
1632         }
1633
1634         #[test]
1635         fn test_check_signature() {
1636                 use crate::TaggedField::*;
1637                 use secp256k1::Secp256k1;
1638                 use secp256k1::ecdsa::{RecoveryId, RecoverableSignature};
1639                 use secp256k1::{SecretKey, PublicKey};
1640                 use crate::{SignedRawInvoice, InvoiceSignature, RawInvoice, RawHrp, RawDataPart, Currency, Sha256,
1641                          PositiveTimestamp};
1642
1643                 let invoice = SignedRawInvoice {
1644                         raw_invoice: RawInvoice {
1645                                 hrp: RawHrp {
1646                                         currency: Currency::Bitcoin,
1647                                         raw_amount: None,
1648                                         si_prefix: None,
1649                                 },
1650                                 data: RawDataPart {
1651                                         timestamp: PositiveTimestamp::from_unix_timestamp(1496314658).unwrap(),
1652                                         tagged_fields: vec ! [
1653                                                 PaymentHash(Sha256(sha256::Hash::from_hex(
1654                                                         "0001020304050607080900010203040506070809000102030405060708090102"
1655                                                 ).unwrap())).into(),
1656                                                 Description(
1657                                                         crate::Description::new(
1658                                                                 "Please consider supporting this project".to_owned()
1659                                                         ).unwrap()
1660                                                 ).into(),
1661                                         ],
1662                                 },
1663                         },
1664                         hash: [
1665                                 0xc3, 0xd4, 0xe8, 0x3f, 0x64, 0x6f, 0xa7, 0x9a, 0x39, 0x3d, 0x75, 0x27,
1666                                 0x7b, 0x1d, 0x85, 0x8d, 0xb1, 0xd1, 0xf7, 0xab, 0x71, 0x37, 0xdc, 0xb7,
1667                                 0x83, 0x5d, 0xb2, 0xec, 0xd5, 0x18, 0xe1, 0xc9
1668                         ],
1669                         signature: InvoiceSignature(RecoverableSignature::from_compact(
1670                                 & [
1671                                         0x38u8, 0xec, 0x68, 0x91, 0x34, 0x5e, 0x20, 0x41, 0x45, 0xbe, 0x8a,
1672                                         0x3a, 0x99, 0xde, 0x38, 0xe9, 0x8a, 0x39, 0xd6, 0xa5, 0x69, 0x43,
1673                                         0x4e, 0x18, 0x45, 0xc8, 0xaf, 0x72, 0x05, 0xaf, 0xcf, 0xcc, 0x7f,
1674                                         0x42, 0x5f, 0xcd, 0x14, 0x63, 0xe9, 0x3c, 0x32, 0x88, 0x1e, 0xad,
1675                                         0x0d, 0x6e, 0x35, 0x6d, 0x46, 0x7e, 0xc8, 0xc0, 0x25, 0x53, 0xf9,
1676                                         0xaa, 0xb1, 0x5e, 0x57, 0x38, 0xb1, 0x1f, 0x12, 0x7f
1677                                 ],
1678                                 RecoveryId::from_i32(0).unwrap()
1679                         ).unwrap()),
1680                 };
1681
1682                 assert!(invoice.check_signature());
1683
1684                 let private_key = SecretKey::from_slice(
1685                         &[
1686                                 0xe1, 0x26, 0xf6, 0x8f, 0x7e, 0xaf, 0xcc, 0x8b, 0x74, 0xf5, 0x4d, 0x26, 0x9f, 0xe2,
1687                                 0x06, 0xbe, 0x71, 0x50, 0x00, 0xf9, 0x4d, 0xac, 0x06, 0x7d, 0x1c, 0x04, 0xa8, 0xca,
1688                                 0x3b, 0x2d, 0xb7, 0x34
1689                         ][..]
1690                 ).unwrap();
1691                 let public_key = PublicKey::from_secret_key(&Secp256k1::new(), &private_key);
1692
1693                 assert_eq!(invoice.recover_payee_pub_key(), Ok(crate::PayeePubKey(public_key)));
1694
1695                 let (raw_invoice, _, _) = invoice.into_parts();
1696                 let new_signed = raw_invoice.sign::<_, ()>(|hash| {
1697                         Ok(Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key))
1698                 }).unwrap();
1699
1700                 assert!(new_signed.check_signature());
1701         }
1702
1703         #[test]
1704         fn test_check_feature_bits() {
1705                 use crate::TaggedField::*;
1706                 use lightning::ln::features::InvoiceFeatures;
1707                 use secp256k1::Secp256k1;
1708                 use secp256k1::SecretKey;
1709                 use crate::{RawInvoice, RawHrp, RawDataPart, Currency, Sha256, PositiveTimestamp, Invoice,
1710                          SemanticError};
1711
1712                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
1713                 let payment_secret = lightning::ln::PaymentSecret([21; 32]);
1714                 let invoice_template = RawInvoice {
1715                         hrp: RawHrp {
1716                                 currency: Currency::Bitcoin,
1717                                 raw_amount: None,
1718                                 si_prefix: None,
1719                         },
1720                         data: RawDataPart {
1721                                 timestamp: PositiveTimestamp::from_unix_timestamp(1496314658).unwrap(),
1722                                 tagged_fields: vec ! [
1723                                         PaymentHash(Sha256(sha256::Hash::from_hex(
1724                                                 "0001020304050607080900010203040506070809000102030405060708090102"
1725                                         ).unwrap())).into(),
1726                                         Description(
1727                                                 crate::Description::new(
1728                                                         "Please consider supporting this project".to_owned()
1729                                                 ).unwrap()
1730                                         ).into(),
1731                                 ],
1732                         },
1733                 };
1734
1735                 // Missing features
1736                 let invoice = {
1737                         let mut invoice = invoice_template.clone();
1738                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1739                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)))
1740                 }.unwrap();
1741                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::InvalidFeatures));
1742
1743                 // Missing feature bits
1744                 let invoice = {
1745                         let mut invoice = invoice_template.clone();
1746                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1747                         invoice.data.tagged_fields.push(Features(InvoiceFeatures::empty()).into());
1748                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)))
1749                 }.unwrap();
1750                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::InvalidFeatures));
1751
1752                 let mut payment_secret_features = InvoiceFeatures::empty();
1753                 payment_secret_features.set_payment_secret_required();
1754
1755                 // Including payment secret and feature bits
1756                 let invoice = {
1757                         let mut invoice = invoice_template.clone();
1758                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1759                         invoice.data.tagged_fields.push(Features(payment_secret_features.clone()).into());
1760                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)))
1761                 }.unwrap();
1762                 assert!(Invoice::from_signed(invoice).is_ok());
1763
1764                 // No payment secret or features
1765                 let invoice = {
1766                         let invoice = invoice_template.clone();
1767                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)))
1768                 }.unwrap();
1769                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::NoPaymentSecret));
1770
1771                 // No payment secret or feature bits
1772                 let invoice = {
1773                         let mut invoice = invoice_template.clone();
1774                         invoice.data.tagged_fields.push(Features(InvoiceFeatures::empty()).into());
1775                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)))
1776                 }.unwrap();
1777                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::NoPaymentSecret));
1778
1779                 // Missing payment secret
1780                 let invoice = {
1781                         let mut invoice = invoice_template.clone();
1782                         invoice.data.tagged_fields.push(Features(payment_secret_features).into());
1783                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)))
1784                 }.unwrap();
1785                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::NoPaymentSecret));
1786
1787                 // Multiple payment secrets
1788                 let invoice = {
1789                         let mut invoice = invoice_template;
1790                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1791                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1792                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)))
1793                 }.unwrap();
1794                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::MultiplePaymentSecrets));
1795         }
1796
1797         #[test]
1798         fn test_builder_amount() {
1799                 use crate::*;
1800
1801                 let builder = InvoiceBuilder::new(Currency::Bitcoin)
1802                         .description("Test".into())
1803                         .payment_hash(sha256::Hash::from_slice(&[0;32][..]).unwrap())
1804                         .duration_since_epoch(Duration::from_secs(1234567));
1805
1806                 let invoice = builder.clone()
1807                         .amount_milli_satoshis(1500)
1808                         .build_raw()
1809                         .unwrap();
1810
1811                 assert_eq!(invoice.hrp.si_prefix, Some(SiPrefix::Nano));
1812                 assert_eq!(invoice.hrp.raw_amount, Some(15));
1813
1814
1815                 let invoice = builder
1816                         .amount_milli_satoshis(150)
1817                         .build_raw()
1818                         .unwrap();
1819
1820                 assert_eq!(invoice.hrp.si_prefix, Some(SiPrefix::Pico));
1821                 assert_eq!(invoice.hrp.raw_amount, Some(1500));
1822         }
1823
1824         #[test]
1825         fn test_builder_fail() {
1826                 use crate::*;
1827                 use lightning::routing::router::RouteHintHop;
1828                 use std::iter::FromIterator;
1829                 use secp256k1::PublicKey;
1830
1831                 let builder = InvoiceBuilder::new(Currency::Bitcoin)
1832                         .payment_hash(sha256::Hash::from_slice(&[0;32][..]).unwrap())
1833                         .duration_since_epoch(Duration::from_secs(1234567))
1834                         .min_final_cltv_expiry_delta(144);
1835
1836                 let too_long_string = String::from_iter(
1837                         (0..1024).map(|_| '?')
1838                 );
1839
1840                 let long_desc_res = builder.clone()
1841                         .description(too_long_string)
1842                         .build_raw();
1843                 assert_eq!(long_desc_res, Err(CreationError::DescriptionTooLong));
1844
1845                 let route_hop = RouteHintHop {
1846                         src_node_id: PublicKey::from_slice(
1847                                         &[
1848                                                 0x03, 0x9e, 0x03, 0xa9, 0x01, 0xb8, 0x55, 0x34, 0xff, 0x1e, 0x92, 0xc4,
1849                                                 0x3c, 0x74, 0x43, 0x1f, 0x7c, 0xe7, 0x20, 0x46, 0x06, 0x0f, 0xcf, 0x7a,
1850                                                 0x95, 0xc3, 0x7e, 0x14, 0x8f, 0x78, 0xc7, 0x72, 0x55
1851                                         ][..]
1852                                 ).unwrap(),
1853                         short_channel_id: 0,
1854                         fees: RoutingFees {
1855                                 base_msat: 0,
1856                                 proportional_millionths: 0,
1857                         },
1858                         cltv_expiry_delta: 0,
1859                         htlc_minimum_msat: None,
1860                         htlc_maximum_msat: None,
1861                 };
1862                 let too_long_route = RouteHint(vec![route_hop; 13]);
1863                 let long_route_res = builder.clone()
1864                         .description("Test".into())
1865                         .private_route(too_long_route)
1866                         .build_raw();
1867                 assert_eq!(long_route_res, Err(CreationError::RouteTooLong));
1868
1869                 let sign_error_res = builder
1870                         .description("Test".into())
1871                         .payment_secret(PaymentSecret([0; 32]))
1872                         .try_build_signed(|_| {
1873                                 Err("ImaginaryError")
1874                         });
1875                 assert_eq!(sign_error_res, Err(SignOrCreationError::SignError("ImaginaryError")));
1876         }
1877
1878         #[test]
1879         fn test_builder_ok() {
1880                 use crate::*;
1881                 use lightning::routing::router::RouteHintHop;
1882                 use secp256k1::Secp256k1;
1883                 use secp256k1::{SecretKey, PublicKey};
1884                 use std::time::{UNIX_EPOCH, Duration};
1885
1886                 let secp_ctx = Secp256k1::new();
1887
1888                 let private_key = SecretKey::from_slice(
1889                         &[
1890                                 0xe1, 0x26, 0xf6, 0x8f, 0x7e, 0xaf, 0xcc, 0x8b, 0x74, 0xf5, 0x4d, 0x26, 0x9f, 0xe2,
1891                                 0x06, 0xbe, 0x71, 0x50, 0x00, 0xf9, 0x4d, 0xac, 0x06, 0x7d, 0x1c, 0x04, 0xa8, 0xca,
1892                                 0x3b, 0x2d, 0xb7, 0x34
1893                         ][..]
1894                 ).unwrap();
1895                 let public_key = PublicKey::from_secret_key(&secp_ctx, &private_key);
1896
1897                 let route_1 = RouteHint(vec![
1898                         RouteHintHop {
1899                                 src_node_id: public_key,
1900                                 short_channel_id: de::parse_int_be(&[123; 8], 256).expect("short chan ID slice too big?"),
1901                                 fees: RoutingFees {
1902                                         base_msat: 2,
1903                                         proportional_millionths: 1,
1904                                 },
1905                                 cltv_expiry_delta: 145,
1906                                 htlc_minimum_msat: None,
1907                                 htlc_maximum_msat: None,
1908                         },
1909                         RouteHintHop {
1910                                 src_node_id: public_key,
1911                                 short_channel_id: de::parse_int_be(&[42; 8], 256).expect("short chan ID slice too big?"),
1912                                 fees: RoutingFees {
1913                                         base_msat: 3,
1914                                         proportional_millionths: 2,
1915                                 },
1916                                 cltv_expiry_delta: 146,
1917                                 htlc_minimum_msat: None,
1918                                 htlc_maximum_msat: None,
1919                         }
1920                 ]);
1921
1922                 let route_2 = RouteHint(vec![
1923                         RouteHintHop {
1924                                 src_node_id: public_key,
1925                                 short_channel_id: 0,
1926                                 fees: RoutingFees {
1927                                         base_msat: 4,
1928                                         proportional_millionths: 3,
1929                                 },
1930                                 cltv_expiry_delta: 147,
1931                                 htlc_minimum_msat: None,
1932                                 htlc_maximum_msat: None,
1933                         },
1934                         RouteHintHop {
1935                                 src_node_id: public_key,
1936                                 short_channel_id: de::parse_int_be(&[1; 8], 256).expect("short chan ID slice too big?"),
1937                                 fees: RoutingFees {
1938                                         base_msat: 5,
1939                                         proportional_millionths: 4,
1940                                 },
1941                                 cltv_expiry_delta: 148,
1942                                 htlc_minimum_msat: None,
1943                                 htlc_maximum_msat: None,
1944                         }
1945                 ]);
1946
1947                 let builder = InvoiceBuilder::new(Currency::BitcoinTestnet)
1948                         .amount_milli_satoshis(123)
1949                         .duration_since_epoch(Duration::from_secs(1234567))
1950                         .payee_pub_key(public_key)
1951                         .expiry_time(Duration::from_secs(54321))
1952                         .min_final_cltv_expiry_delta(144)
1953                         .fallback(Fallback::PubKeyHash([0;20]))
1954                         .private_route(route_1.clone())
1955                         .private_route(route_2.clone())
1956                         .description_hash(sha256::Hash::from_slice(&[3;32][..]).unwrap())
1957                         .payment_hash(sha256::Hash::from_slice(&[21;32][..]).unwrap())
1958                         .payment_secret(PaymentSecret([42; 32]))
1959                         .basic_mpp();
1960
1961                 let invoice = builder.clone().build_signed(|hash| {
1962                         secp_ctx.sign_ecdsa_recoverable(hash, &private_key)
1963                 }).unwrap();
1964
1965                 assert!(invoice.check_signature().is_ok());
1966                 assert_eq!(invoice.tagged_fields().count(), 10);
1967
1968                 assert_eq!(invoice.amount_milli_satoshis(), Some(123));
1969                 assert_eq!(invoice.amount_pico_btc(), Some(1230));
1970                 assert_eq!(invoice.currency(), Currency::BitcoinTestnet);
1971                 #[cfg(feature = "std")]
1972                 assert_eq!(
1973                         invoice.timestamp().duration_since(UNIX_EPOCH).unwrap().as_secs(),
1974                         1234567
1975                 );
1976                 assert_eq!(invoice.payee_pub_key(), Some(&public_key));
1977                 assert_eq!(invoice.expiry_time(), Duration::from_secs(54321));
1978                 assert_eq!(invoice.min_final_cltv_expiry_delta(), 144);
1979                 assert_eq!(invoice.fallbacks(), vec![&Fallback::PubKeyHash([0;20])]);
1980                 assert_eq!(invoice.private_routes(), vec![&PrivateRoute(route_1), &PrivateRoute(route_2)]);
1981                 assert_eq!(
1982                         invoice.description(),
1983                         InvoiceDescription::Hash(&Sha256(sha256::Hash::from_slice(&[3;32][..]).unwrap()))
1984                 );
1985                 assert_eq!(invoice.payment_hash(), &sha256::Hash::from_slice(&[21;32][..]).unwrap());
1986                 assert_eq!(invoice.payment_secret(), &PaymentSecret([42; 32]));
1987
1988                 let mut expected_features = InvoiceFeatures::empty();
1989                 expected_features.set_variable_length_onion_required();
1990                 expected_features.set_payment_secret_required();
1991                 expected_features.set_basic_mpp_optional();
1992                 assert_eq!(invoice.features(), Some(&expected_features));
1993
1994                 let raw_invoice = builder.build_raw().unwrap();
1995                 assert_eq!(raw_invoice, *invoice.into_signed_raw().raw_invoice())
1996         }
1997
1998         #[test]
1999         fn test_default_values() {
2000                 use crate::*;
2001                 use secp256k1::Secp256k1;
2002                 use secp256k1::SecretKey;
2003
2004                 let signed_invoice = InvoiceBuilder::new(Currency::Bitcoin)
2005                         .description("Test".into())
2006                         .payment_hash(sha256::Hash::from_slice(&[0;32][..]).unwrap())
2007                         .payment_secret(PaymentSecret([0; 32]))
2008                         .duration_since_epoch(Duration::from_secs(1234567))
2009                         .build_raw()
2010                         .unwrap()
2011                         .sign::<_, ()>(|hash| {
2012                                 let privkey = SecretKey::from_slice(&[41; 32]).unwrap();
2013                                 let secp_ctx = Secp256k1::new();
2014                                 Ok(secp_ctx.sign_ecdsa_recoverable(hash, &privkey))
2015                         })
2016                         .unwrap();
2017                 let invoice = Invoice::from_signed(signed_invoice).unwrap();
2018
2019                 assert_eq!(invoice.min_final_cltv_expiry_delta(), DEFAULT_MIN_FINAL_CLTV_EXPIRY_DELTA);
2020                 assert_eq!(invoice.expiry_time(), Duration::from_secs(DEFAULT_EXPIRY_TIME));
2021                 assert!(!invoice.would_expire(Duration::from_secs(1234568)));
2022         }
2023
2024         #[test]
2025         fn test_expiration() {
2026                 use crate::*;
2027                 use secp256k1::Secp256k1;
2028                 use secp256k1::SecretKey;
2029
2030                 let signed_invoice = InvoiceBuilder::new(Currency::Bitcoin)
2031                         .description("Test".into())
2032                         .payment_hash(sha256::Hash::from_slice(&[0;32][..]).unwrap())
2033                         .payment_secret(PaymentSecret([0; 32]))
2034                         .duration_since_epoch(Duration::from_secs(1234567))
2035                         .build_raw()
2036                         .unwrap()
2037                         .sign::<_, ()>(|hash| {
2038                                 let privkey = SecretKey::from_slice(&[41; 32]).unwrap();
2039                                 let secp_ctx = Secp256k1::new();
2040                                 Ok(secp_ctx.sign_ecdsa_recoverable(hash, &privkey))
2041                         })
2042                         .unwrap();
2043                 let invoice = Invoice::from_signed(signed_invoice).unwrap();
2044
2045                 assert!(invoice.would_expire(Duration::from_secs(1234567 + DEFAULT_EXPIRY_TIME + 1)));
2046         }
2047
2048         #[cfg(feature = "serde")]
2049         #[test]
2050         fn test_serde() {
2051                 let invoice_str = "lnbc100p1psj9jhxdqud3jxktt5w46x7unfv9kz6mn0v3jsnp4q0d3p2sfluzdx45tqcs\
2052                         h2pu5qc7lgq0xs578ngs6s0s68ua4h7cvspp5q6rmq35js88zp5dvwrv9m459tnk2zunwj5jalqtyxqulh0l\
2053                         5gflssp5nf55ny5gcrfl30xuhzj3nphgj27rstekmr9fw3ny5989s300gyus9qyysgqcqpcrzjqw2sxwe993\
2054                         h5pcm4dxzpvttgza8zhkqxpgffcrf5v25nwpr3cmfg7z54kuqq8rgqqqqqqqq2qqqqq9qq9qrzjqd0ylaqcl\
2055                         j9424x9m8h2vcukcgnm6s56xfgu3j78zyqzhgs4hlpzvznlugqq9vsqqqqqqqlgqqqqqeqq9qrzjqwldmj9d\
2056                         ha74df76zhx6l9we0vjdquygcdt3kssupehe64g6yyp5yz5rhuqqwccqqyqqqqlgqqqqjcqq9qrzjqf9e58a\
2057                         guqr0rcun0ajlvmzq3ek63cw2w282gv3z5uupmuwvgjtq2z55qsqqg6qqqyqqqrtnqqqzq3cqygrzjqvphms\
2058                         ywntrrhqjcraumvc4y6r8v4z5v593trte429v4hredj7ms5z52usqq9ngqqqqqqqlgqqqqqqgq9qrzjq2v0v\
2059                         p62g49p7569ev48cmulecsxe59lvaw3wlxm7r982zxa9zzj7z5l0cqqxusqqyqqqqlgqqqqqzsqygarl9fh3\
2060                         8s0gyuxjjgux34w75dnc6xp2l35j7es3jd4ugt3lu0xzre26yg5m7ke54n2d5sym4xcmxtl8238xxvw5h5h5\
2061                         j5r6drg6k6zcqj0fcwg";
2062                 let invoice = invoice_str.parse::<super::Invoice>().unwrap();
2063                 let serialized_invoice = serde_json::to_string(&invoice).unwrap();
2064                 let deserialized_invoice: super::Invoice = serde_json::from_str(serialized_invoice.as_str()).unwrap();
2065                 assert_eq!(invoice, deserialized_invoice);
2066                 assert_eq!(invoice_str, deserialized_invoice.to_string().as_str());
2067                 assert_eq!(invoice_str, serialized_invoice.as_str().trim_matches('\"'));
2068         }
2069 }