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Merge pull request #1706 from jkczyz/2022-09-filtered-blocks
[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 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, 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, 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(::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`].
158 ///
159 /// [BOLT 11]: https://github.com/lightning/bolts/blob/master/11-payment-encoding.md
160 /// [`MIN_FINAL_CLTV_EXPIRY`]: lightning::ln::channelmanager::MIN_FINAL_CLTV_EXPIRY
161 pub const DEFAULT_MIN_FINAL_CLTV_EXPIRY: 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(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 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         MinFinalCltvExpiry(MinFinalCltvExpiry),
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` to use for the last HTLC in the route
442 #[derive(Clone, Debug, Hash, Eq, PartialEq)]
443 pub struct MinFinalCltvExpiry(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: 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
544         pub fn expiry_time(mut self, expiry_time: Duration) -> Self {
545                 self.tagged_fields.push(TaggedField::ExpiryTime(ExpiryTime::from_duration(expiry_time)));
546                 self
547         }
548
549         /// Adds a fallback address.
550         pub fn fallback(mut self, fallback: Fallback) -> Self {
551                 self.tagged_fields.push(TaggedField::Fallback(fallback));
552                 self
553         }
554
555         /// Adds a private route.
556         pub fn private_route(mut self, hint: RouteHint) -> Self {
557                 match PrivateRoute::new(hint) {
558                         Ok(r) => self.tagged_fields.push(TaggedField::PrivateRoute(r)),
559                         Err(e) => self.error = Some(e),
560                 }
561                 self
562         }
563 }
564
565 impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, tb::True, C, S> {
566         /// Builds a `RawInvoice` if no `CreationError` occurred while construction any of the fields.
567         pub fn build_raw(self) -> Result<RawInvoice, CreationError> {
568
569                 // If an error occurred at any time before, return it now
570                 if let Some(e) = self.error {
571                         return Err(e);
572                 }
573
574                 let hrp = RawHrp {
575                         currency: self.currency,
576                         raw_amount: self.amount,
577                         si_prefix: self.si_prefix,
578                 };
579
580                 let timestamp = self.timestamp.expect("ensured to be Some(t) by type T");
581
582                 let tagged_fields = self.tagged_fields.into_iter().map(|tf| {
583                         RawTaggedField::KnownSemantics(tf)
584                 }).collect::<Vec<_>>();
585
586                 let data = RawDataPart {
587                         timestamp: timestamp,
588                         tagged_fields: tagged_fields,
589                 };
590
591                 Ok(RawInvoice {
592                         hrp: hrp,
593                         data: data,
594                 })
595         }
596 }
597
598 impl<H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<tb::False, H, T, C, S> {
599         /// Set the description. This function is only available if no description (hash) was set.
600         pub fn description(mut self, description: String) -> InvoiceBuilder<tb::True, H, T, C, S> {
601                 match Description::new(description) {
602                         Ok(d) => self.tagged_fields.push(TaggedField::Description(d)),
603                         Err(e) => self.error = Some(e),
604                 }
605                 self.set_flags()
606         }
607
608         /// Set the description hash. This function is only available if no description (hash) was set.
609         pub fn description_hash(mut self, description_hash: sha256::Hash) -> InvoiceBuilder<tb::True, H, T, C, S> {
610                 self.tagged_fields.push(TaggedField::DescriptionHash(Sha256(description_hash)));
611                 self.set_flags()
612         }
613 }
614
615 impl<D: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, tb::False, T, C, S> {
616         /// Set the payment hash. This function is only available if no payment hash was set.
617         pub fn payment_hash(mut self, hash: sha256::Hash) -> InvoiceBuilder<D, tb::True, T, C, S> {
618                 self.tagged_fields.push(TaggedField::PaymentHash(Sha256(hash)));
619                 self.set_flags()
620         }
621 }
622
623 impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, tb::False, C, S> {
624         /// Sets the timestamp to a specific [`SystemTime`].
625         #[cfg(feature = "std")]
626         pub fn timestamp(mut self, time: SystemTime) -> InvoiceBuilder<D, H, tb::True, C, S> {
627                 match PositiveTimestamp::from_system_time(time) {
628                         Ok(t) => self.timestamp = Some(t),
629                         Err(e) => self.error = Some(e),
630                 }
631
632                 self.set_flags()
633         }
634
635         /// Sets the timestamp to a duration since the Unix epoch.
636         pub fn duration_since_epoch(mut self, time: Duration) -> InvoiceBuilder<D, H, tb::True, C, S> {
637                 match PositiveTimestamp::from_duration_since_epoch(time) {
638                         Ok(t) => self.timestamp = Some(t),
639                         Err(e) => self.error = Some(e),
640                 }
641
642                 self.set_flags()
643         }
644
645         /// Sets the timestamp to the current system time.
646         #[cfg(feature = "std")]
647         pub fn current_timestamp(mut self) -> InvoiceBuilder<D, H, tb::True, C, S> {
648                 let now = PositiveTimestamp::from_system_time(SystemTime::now());
649                 self.timestamp = Some(now.expect("for the foreseeable future this shouldn't happen"));
650                 self.set_flags()
651         }
652 }
653
654 impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, T, tb::False, S> {
655         /// Sets `min_final_cltv_expiry`.
656         pub fn min_final_cltv_expiry(mut self, min_final_cltv_expiry: u64) -> InvoiceBuilder<D, H, T, tb::True, S> {
657                 self.tagged_fields.push(TaggedField::MinFinalCltvExpiry(MinFinalCltvExpiry(min_final_cltv_expiry)));
658                 self.set_flags()
659         }
660 }
661
662 impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, T, C, tb::False> {
663         /// Sets the payment secret and relevant features.
664         pub fn payment_secret(mut self, payment_secret: PaymentSecret) -> InvoiceBuilder<D, H, T, C, tb::True> {
665                 let mut features = InvoiceFeatures::empty();
666                 features.set_variable_length_onion_required();
667                 features.set_payment_secret_required();
668                 self.tagged_fields.push(TaggedField::PaymentSecret(payment_secret));
669                 self.tagged_fields.push(TaggedField::Features(features));
670                 self.set_flags()
671         }
672 }
673
674 impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, T, C, tb::True> {
675         /// Sets the `basic_mpp` feature as optional.
676         pub fn basic_mpp(mut self) -> Self {
677                 for field in self.tagged_fields.iter_mut() {
678                         if let TaggedField::Features(f) = field {
679                                 f.set_basic_mpp_optional();
680                         }
681                 }
682                 self
683         }
684 }
685
686 impl InvoiceBuilder<tb::True, tb::True, tb::True, tb::True, tb::True> {
687         /// Builds and signs an invoice using the supplied `sign_function`. This function MAY NOT fail
688         /// and MUST produce a recoverable signature valid for the given hash and if applicable also for
689         /// the included payee public key.
690         pub fn build_signed<F>(self, sign_function: F) -> Result<Invoice, CreationError>
691                 where F: FnOnce(&Message) -> RecoverableSignature
692         {
693                 let invoice = self.try_build_signed::<_, ()>(|hash| {
694                         Ok(sign_function(hash))
695                 });
696
697                 match invoice {
698                         Ok(i) => Ok(i),
699                         Err(SignOrCreationError::CreationError(e)) => Err(e),
700                         Err(SignOrCreationError::SignError(())) => unreachable!(),
701                 }
702         }
703
704         /// Builds and signs an invoice using the supplied `sign_function`. This function MAY fail with
705         /// an error of type `E` and MUST produce a recoverable signature valid for the given hash and
706         /// if applicable also for the included payee public key.
707         pub fn try_build_signed<F, E>(self, sign_function: F) -> Result<Invoice, SignOrCreationError<E>>
708                 where F: FnOnce(&Message) -> Result<RecoverableSignature, E>
709         {
710                 let raw = match self.build_raw() {
711                         Ok(r) => r,
712                         Err(e) => return Err(SignOrCreationError::CreationError(e)),
713                 };
714
715                 let signed = match raw.sign(sign_function) {
716                         Ok(s) => s,
717                         Err(e) => return Err(SignOrCreationError::SignError(e)),
718                 };
719
720                 let invoice = Invoice {
721                         signed_invoice: signed,
722                 };
723
724                 invoice.check_field_counts().expect("should be ensured by type signature of builder");
725                 invoice.check_feature_bits().expect("should be ensured by type signature of builder");
726                 invoice.check_amount().expect("should be ensured by type signature of builder");
727
728                 Ok(invoice)
729         }
730 }
731
732
733 impl SignedRawInvoice {
734         /// Disassembles the `SignedRawInvoice` into its three parts:
735         ///  1. raw invoice
736         ///  2. hash of the raw invoice
737         ///  3. signature
738         pub fn into_parts(self) -> (RawInvoice, [u8; 32], InvoiceSignature) {
739                 (self.raw_invoice, self.hash, self.signature)
740         }
741
742         /// The `RawInvoice` which was signed.
743         pub fn raw_invoice(&self) -> &RawInvoice {
744                 &self.raw_invoice
745         }
746
747         /// The hash of the `RawInvoice` that was signed.
748         pub fn signable_hash(&self) -> &[u8; 32] {
749                 &self.hash
750         }
751
752         /// InvoiceSignature for the invoice.
753         pub fn signature(&self) -> &InvoiceSignature {
754                 &self.signature
755         }
756
757         /// Recovers the public key used for signing the invoice from the recoverable signature.
758         pub fn recover_payee_pub_key(&self) -> Result<PayeePubKey, secp256k1::Error> {
759                 let hash = Message::from_slice(&self.hash[..])
760                         .expect("Hash is 32 bytes long, same as MESSAGE_SIZE");
761
762                 Ok(PayeePubKey(Secp256k1::new().recover_ecdsa(
763                         &hash,
764                         &self.signature
765                 )?))
766         }
767
768         /// Checks if the signature is valid for the included payee public key or if none exists if it's
769         /// valid for the recovered signature (which should always be true?).
770         pub fn check_signature(&self) -> bool {
771                 let included_pub_key = self.raw_invoice.payee_pub_key();
772
773                 let mut recovered_pub_key = Option::None;
774                 if recovered_pub_key.is_none() {
775                         let recovered = match self.recover_payee_pub_key() {
776                                 Ok(pk) => pk,
777                                 Err(_) => return false,
778                         };
779                         recovered_pub_key = Some(recovered);
780                 }
781
782                 let pub_key = included_pub_key.or_else(|| recovered_pub_key.as_ref())
783                         .expect("One is always present");
784
785                 let hash = Message::from_slice(&self.hash[..])
786                         .expect("Hash is 32 bytes long, same as MESSAGE_SIZE");
787
788                 let secp_context = Secp256k1::new();
789                 let verification_result = secp_context.verify_ecdsa(
790                         &hash,
791                         &self.signature.to_standard(),
792                         pub_key
793                 );
794
795                 match verification_result {
796                         Ok(()) => true,
797                         Err(_) => false,
798                 }
799         }
800 }
801
802 /// Finds the first element of an enum stream of a given variant and extracts one member of the
803 /// variant. If no element was found `None` gets returned.
804 ///
805 /// The following example would extract the first B.
806 ///
807 /// enum Enum {
808 ///     A(u8),
809 ///     B(u16)
810 /// }
811 ///
812 /// let elements = vec![Enum::A(1), Enum::A(2), Enum::B(3), Enum::A(4)];
813 ///
814 /// assert_eq!(find_extract!(elements.iter(), Enum::B(x), x), Some(3u16));
815 macro_rules! find_extract {
816         ($iter:expr, $enm:pat, $enm_var:ident) => {
817                 find_all_extract!($iter, $enm, $enm_var).next()
818         };
819 }
820
821 /// Finds the all elements of an enum stream of a given variant and extracts one member of the
822 /// variant through an iterator.
823 ///
824 /// The following example would extract all A.
825 ///
826 /// enum Enum {
827 ///     A(u8),
828 ///     B(u16)
829 /// }
830 ///
831 /// let elements = vec![Enum::A(1), Enum::A(2), Enum::B(3), Enum::A(4)];
832 ///
833 /// assert_eq!(
834 ///     find_all_extract!(elements.iter(), Enum::A(x), x).collect::<Vec<u8>>(),
835 ///     vec![1u8, 2u8, 4u8]
836 /// );
837 macro_rules! find_all_extract {
838         ($iter:expr, $enm:pat, $enm_var:ident) => {
839                 $iter.filter_map(|tf| match *tf {
840                         $enm => Some($enm_var),
841                         _ => None,
842                 })
843         };
844 }
845
846 #[allow(missing_docs)]
847 impl RawInvoice {
848         /// Hash the HRP as bytes and signatureless data part.
849         fn hash_from_parts(hrp_bytes: &[u8], data_without_signature: &[u5]) -> [u8; 32] {
850                 let preimage = construct_invoice_preimage(hrp_bytes, data_without_signature);
851                 let mut hash: [u8; 32] = Default::default();
852                 hash.copy_from_slice(&sha256::Hash::hash(&preimage)[..]);
853                 hash
854         }
855
856         /// Calculate the hash of the encoded `RawInvoice` which should be signed.
857         pub fn signable_hash(&self) -> [u8; 32] {
858                 use bech32::ToBase32;
859
860                 RawInvoice::hash_from_parts(
861                         self.hrp.to_string().as_bytes(),
862                         &self.data.to_base32()
863                 )
864         }
865
866         /// Signs the invoice using the supplied `sign_function`. This function MAY fail with an error
867         /// of type `E`. Since the signature of a `SignedRawInvoice` is not required to be valid there
868         /// are no constraints regarding the validity of the produced signature.
869         ///
870         /// (C-not exported) As we don't currently support passing function pointers into methods
871         /// explicitly.
872         pub fn sign<F, E>(self, sign_method: F) -> Result<SignedRawInvoice, E>
873                 where F: FnOnce(&Message) -> Result<RecoverableSignature, E>
874         {
875                 let raw_hash = self.signable_hash();
876                 let hash = Message::from_slice(&raw_hash[..])
877                         .expect("Hash is 32 bytes long, same as MESSAGE_SIZE");
878                 let signature = sign_method(&hash)?;
879
880                 Ok(SignedRawInvoice {
881                         raw_invoice: self,
882                         hash: raw_hash,
883                         signature: InvoiceSignature(signature),
884                 })
885         }
886
887         /// Returns an iterator over all tagged fields with known semantics.
888         ///
889         /// (C-not exported) As there is not yet a manual mapping for a FilterMap
890         pub fn known_tagged_fields(&self)
891                 -> FilterMap<Iter<RawTaggedField>, fn(&RawTaggedField) -> Option<&TaggedField>>
892         {
893                 // For 1.14.0 compatibility: closures' types can't be written an fn()->() in the
894                 // function's type signature.
895                 // TODO: refactor once impl Trait is available
896                 fn match_raw(raw: &RawTaggedField) -> Option<&TaggedField> {
897                         match *raw {
898                                 RawTaggedField::KnownSemantics(ref tf) => Some(tf),
899                                 _ => None,
900                         }
901                 }
902
903                 self.data.tagged_fields.iter().filter_map(match_raw )
904         }
905
906         pub fn payment_hash(&self) -> Option<&Sha256> {
907                 find_extract!(self.known_tagged_fields(), TaggedField::PaymentHash(ref x), x)
908         }
909
910         pub fn description(&self) -> Option<&Description> {
911                 find_extract!(self.known_tagged_fields(), TaggedField::Description(ref x), x)
912         }
913
914         pub fn payee_pub_key(&self) -> Option<&PayeePubKey> {
915                 find_extract!(self.known_tagged_fields(), TaggedField::PayeePubKey(ref x), x)
916         }
917
918         pub fn description_hash(&self) -> Option<&Sha256> {
919                 find_extract!(self.known_tagged_fields(), TaggedField::DescriptionHash(ref x), x)
920         }
921
922         pub fn expiry_time(&self) -> Option<&ExpiryTime> {
923                 find_extract!(self.known_tagged_fields(), TaggedField::ExpiryTime(ref x), x)
924         }
925
926         pub fn min_final_cltv_expiry(&self) -> Option<&MinFinalCltvExpiry> {
927                 find_extract!(self.known_tagged_fields(), TaggedField::MinFinalCltvExpiry(ref x), x)
928         }
929
930         pub fn payment_secret(&self) -> Option<&PaymentSecret> {
931                 find_extract!(self.known_tagged_fields(), TaggedField::PaymentSecret(ref x), x)
932         }
933
934         pub fn features(&self) -> Option<&InvoiceFeatures> {
935                 find_extract!(self.known_tagged_fields(), TaggedField::Features(ref x), x)
936         }
937
938         /// (C-not exported) as we don't support Vec<&NonOpaqueType>
939         pub fn fallbacks(&self) -> Vec<&Fallback> {
940                 find_all_extract!(self.known_tagged_fields(), TaggedField::Fallback(ref x), x).collect()
941         }
942
943         pub fn private_routes(&self) -> Vec<&PrivateRoute> {
944                 find_all_extract!(self.known_tagged_fields(), TaggedField::PrivateRoute(ref x), x).collect()
945         }
946
947         pub fn amount_pico_btc(&self) -> Option<u64> {
948                 self.hrp.raw_amount.map(|v| {
949                         v * self.hrp.si_prefix.as_ref().map_or(1_000_000_000_000, |si| { si.multiplier() })
950                 })
951         }
952
953         pub fn currency(&self) -> Currency {
954                 self.hrp.currency.clone()
955         }
956 }
957
958 impl PositiveTimestamp {
959         /// Creates a `PositiveTimestamp` from a Unix timestamp in the range `0..=MAX_TIMESTAMP`.
960         ///
961         /// Otherwise, returns a [`CreationError::TimestampOutOfBounds`].
962         pub fn from_unix_timestamp(unix_seconds: u64) -> Result<Self, CreationError> {
963                 Self::from_duration_since_epoch(Duration::from_secs(unix_seconds))
964         }
965
966         /// Creates a `PositiveTimestamp` from a [`SystemTime`] with a corresponding Unix timestamp in
967         /// the range `0..=MAX_TIMESTAMP`.
968         ///
969         /// Otherwise, returns a [`CreationError::TimestampOutOfBounds`].
970         #[cfg(feature = "std")]
971         pub fn from_system_time(time: SystemTime) -> Result<Self, CreationError> {
972                 time.duration_since(SystemTime::UNIX_EPOCH)
973                         .map(Self::from_duration_since_epoch)
974                         .unwrap_or(Err(CreationError::TimestampOutOfBounds))
975         }
976
977         /// Creates a `PositiveTimestamp` from a [`Duration`] since the Unix epoch in the range
978         /// `0..=MAX_TIMESTAMP`.
979         ///
980         /// Otherwise, returns a [`CreationError::TimestampOutOfBounds`].
981         pub fn from_duration_since_epoch(duration: Duration) -> Result<Self, CreationError> {
982                 if duration.as_secs() <= MAX_TIMESTAMP {
983                         Ok(PositiveTimestamp(duration))
984                 } else {
985                         Err(CreationError::TimestampOutOfBounds)
986                 }
987         }
988
989         /// Returns the Unix timestamp representing the stored time
990         pub fn as_unix_timestamp(&self) -> u64 {
991                 self.0.as_secs()
992         }
993
994         /// Returns the duration of the stored time since the Unix epoch
995         pub fn as_duration_since_epoch(&self) -> Duration {
996                 self.0
997         }
998
999         /// Returns the [`SystemTime`] representing the stored time
1000         #[cfg(feature = "std")]
1001         pub fn as_time(&self) -> SystemTime {
1002                 SystemTime::UNIX_EPOCH + self.0
1003         }
1004 }
1005
1006 #[cfg(feature = "std")]
1007 impl Into<SystemTime> for PositiveTimestamp {
1008         fn into(self) -> SystemTime {
1009                 SystemTime::UNIX_EPOCH + self.0
1010         }
1011 }
1012
1013 impl Invoice {
1014         /// Transform the `Invoice` into it's unchecked version
1015         pub fn into_signed_raw(self) -> SignedRawInvoice {
1016                 self.signed_invoice
1017         }
1018
1019         /// Check that all mandatory fields are present
1020         fn check_field_counts(&self) -> Result<(), SemanticError> {
1021                 // "A writer MUST include exactly one p field […]."
1022                 let payment_hash_cnt = self.tagged_fields().filter(|&tf| match *tf {
1023                         TaggedField::PaymentHash(_) => true,
1024                         _ => false,
1025                 }).count();
1026                 if payment_hash_cnt < 1 {
1027                         return Err(SemanticError::NoPaymentHash);
1028                 } else if payment_hash_cnt > 1 {
1029                         return Err(SemanticError::MultiplePaymentHashes);
1030                 }
1031
1032                 // "A writer MUST include either exactly one d or exactly one h field."
1033                 let description_cnt = self.tagged_fields().filter(|&tf| match *tf {
1034                         TaggedField::Description(_) | TaggedField::DescriptionHash(_) => true,
1035                         _ => false,
1036                 }).count();
1037                 if  description_cnt < 1 {
1038                         return Err(SemanticError::NoDescription);
1039                 } else if description_cnt > 1 {
1040                         return  Err(SemanticError::MultipleDescriptions);
1041                 }
1042
1043                 self.check_payment_secret()?;
1044
1045                 Ok(())
1046         }
1047
1048         /// Checks that there is exactly one payment secret field
1049         fn check_payment_secret(&self) -> Result<(), SemanticError> {
1050                 // "A writer MUST include exactly one `s` field."
1051                 let payment_secret_count = self.tagged_fields().filter(|&tf| match *tf {
1052                         TaggedField::PaymentSecret(_) => true,
1053                         _ => false,
1054                 }).count();
1055                 if payment_secret_count < 1 {
1056                         return Err(SemanticError::NoPaymentSecret);
1057                 } else if payment_secret_count > 1 {
1058                         return Err(SemanticError::MultiplePaymentSecrets);
1059                 }
1060
1061                 Ok(())
1062         }
1063
1064         /// Check that amount is a whole number of millisatoshis
1065         fn check_amount(&self) -> Result<(), SemanticError> {
1066                 if let Some(amount_pico_btc) = self.amount_pico_btc() {
1067                         if amount_pico_btc % 10 != 0 {
1068                                 return Err(SemanticError::ImpreciseAmount);
1069                         }
1070                 }
1071                 Ok(())
1072         }
1073
1074         /// Check that feature bits are set as required
1075         fn check_feature_bits(&self) -> Result<(), SemanticError> {
1076                 self.check_payment_secret()?;
1077
1078                 // "A writer MUST set an s field if and only if the payment_secret feature is set."
1079                 // (this requirement has been since removed, and we now require the payment secret
1080                 // feature bit always).
1081                 let features = self.tagged_fields().find(|&tf| match *tf {
1082                         TaggedField::Features(_) => true,
1083                         _ => false,
1084                 });
1085                 match features {
1086                         None => Err(SemanticError::InvalidFeatures),
1087                         Some(TaggedField::Features(features)) => {
1088                                 if features.requires_unknown_bits() {
1089                                         Err(SemanticError::InvalidFeatures)
1090                                 } else if !features.supports_payment_secret() {
1091                                         Err(SemanticError::InvalidFeatures)
1092                                 } else {
1093                                         Ok(())
1094                                 }
1095                         },
1096                         Some(_) => unreachable!(),
1097                 }
1098         }
1099
1100         /// Check that the invoice is signed correctly and that key recovery works
1101         pub fn check_signature(&self) -> Result<(), SemanticError> {
1102                 match self.signed_invoice.recover_payee_pub_key() {
1103                         Err(secp256k1::Error::InvalidRecoveryId) =>
1104                                 return Err(SemanticError::InvalidRecoveryId),
1105                         Err(secp256k1::Error::InvalidSignature) =>
1106                                 return Err(SemanticError::InvalidSignature),
1107                         Err(e) => panic!("no other error may occur, got {:?}", e),
1108                         Ok(_) => {},
1109                 }
1110
1111                 if !self.signed_invoice.check_signature() {
1112                         return Err(SemanticError::InvalidSignature);
1113                 }
1114
1115                 Ok(())
1116         }
1117
1118         /// Constructs an `Invoice` from a `SignedRawInvoice` by checking all its invariants.
1119         /// ```
1120         /// use lightning_invoice::*;
1121         ///
1122         /// let invoice = "lnbc100p1psj9jhxdqud3jxktt5w46x7unfv9kz6mn0v3jsnp4q0d3p2sfluzdx45tqcs\
1123         /// h2pu5qc7lgq0xs578ngs6s0s68ua4h7cvspp5q6rmq35js88zp5dvwrv9m459tnk2zunwj5jalqtyxqulh0l\
1124         /// 5gflssp5nf55ny5gcrfl30xuhzj3nphgj27rstekmr9fw3ny5989s300gyus9qyysgqcqpcrzjqw2sxwe993\
1125         /// h5pcm4dxzpvttgza8zhkqxpgffcrf5v25nwpr3cmfg7z54kuqq8rgqqqqqqqq2qqqqq9qq9qrzjqd0ylaqcl\
1126         /// j9424x9m8h2vcukcgnm6s56xfgu3j78zyqzhgs4hlpzvznlugqq9vsqqqqqqqlgqqqqqeqq9qrzjqwldmj9d\
1127         /// ha74df76zhx6l9we0vjdquygcdt3kssupehe64g6yyp5yz5rhuqqwccqqyqqqqlgqqqqjcqq9qrzjqf9e58a\
1128         /// guqr0rcun0ajlvmzq3ek63cw2w282gv3z5uupmuwvgjtq2z55qsqqg6qqqyqqqrtnqqqzq3cqygrzjqvphms\
1129         /// ywntrrhqjcraumvc4y6r8v4z5v593trte429v4hredj7ms5z52usqq9ngqqqqqqqlgqqqqqqgq9qrzjq2v0v\
1130         /// p62g49p7569ev48cmulecsxe59lvaw3wlxm7r982zxa9zzj7z5l0cqqxusqqyqqqqlgqqqqqzsqygarl9fh3\
1131         /// 8s0gyuxjjgux34w75dnc6xp2l35j7es3jd4ugt3lu0xzre26yg5m7ke54n2d5sym4xcmxtl8238xxvw5h5h5\
1132         /// j5r6drg6k6zcqj0fcwg";
1133         ///
1134         /// let signed = invoice.parse::<SignedRawInvoice>().unwrap();
1135         ///
1136         /// assert!(Invoice::from_signed(signed).is_ok());
1137         /// ```
1138         pub fn from_signed(signed_invoice: SignedRawInvoice) -> Result<Self, SemanticError> {
1139                 let invoice = Invoice {
1140                         signed_invoice: signed_invoice,
1141                 };
1142                 invoice.check_field_counts()?;
1143                 invoice.check_feature_bits()?;
1144                 invoice.check_signature()?;
1145                 invoice.check_amount()?;
1146
1147                 Ok(invoice)
1148         }
1149
1150         /// Returns the `Invoice`'s timestamp (should equal its creation time)
1151         #[cfg(feature = "std")]
1152         pub fn timestamp(&self) -> SystemTime {
1153                 self.signed_invoice.raw_invoice().data.timestamp.as_time()
1154         }
1155
1156         /// Returns the `Invoice`'s timestamp as a duration since the Unix epoch
1157         pub fn duration_since_epoch(&self) -> Duration {
1158                 self.signed_invoice.raw_invoice().data.timestamp.0
1159         }
1160
1161         /// Returns an iterator over all tagged fields of this Invoice.
1162         ///
1163         /// (C-not exported) As there is not yet a manual mapping for a FilterMap
1164         pub fn tagged_fields(&self)
1165                 -> FilterMap<Iter<RawTaggedField>, fn(&RawTaggedField) -> Option<&TaggedField>> {
1166                 self.signed_invoice.raw_invoice().known_tagged_fields()
1167         }
1168
1169         /// Returns the hash to which we will receive the preimage on completion of the payment
1170         pub fn payment_hash(&self) -> &sha256::Hash {
1171                 &self.signed_invoice.payment_hash().expect("checked by constructor").0
1172         }
1173
1174         /// Return the description or a hash of it for longer ones
1175         ///
1176         /// (C-not exported) because we don't yet export InvoiceDescription
1177         pub fn description(&self) -> InvoiceDescription {
1178                 if let Some(ref direct) = self.signed_invoice.description() {
1179                         return InvoiceDescription::Direct(direct);
1180                 } else if let Some(ref hash) = self.signed_invoice.description_hash() {
1181                         return InvoiceDescription::Hash(hash);
1182                 }
1183                 unreachable!("ensured by constructor");
1184         }
1185
1186         /// Get the payee's public key if one was included in the invoice
1187         pub fn payee_pub_key(&self) -> Option<&PublicKey> {
1188                 self.signed_invoice.payee_pub_key().map(|x| &x.0)
1189         }
1190
1191         /// Get the payment secret if one was included in the invoice
1192         pub fn payment_secret(&self) -> &PaymentSecret {
1193                 self.signed_invoice.payment_secret().expect("was checked by constructor")
1194         }
1195
1196         /// Get the invoice features if they were included in the invoice
1197         pub fn features(&self) -> Option<&InvoiceFeatures> {
1198                 self.signed_invoice.features()
1199         }
1200
1201         /// Recover the payee's public key (only to be used if none was included in the invoice)
1202         pub fn recover_payee_pub_key(&self) -> PublicKey {
1203                 self.signed_invoice.recover_payee_pub_key().expect("was checked by constructor").0
1204         }
1205
1206         /// Returns the invoice's expiry time, if present, otherwise [`DEFAULT_EXPIRY_TIME`].
1207         pub fn expiry_time(&self) -> Duration {
1208                 self.signed_invoice.expiry_time()
1209                         .map(|x| x.0)
1210                         .unwrap_or(Duration::from_secs(DEFAULT_EXPIRY_TIME))
1211         }
1212
1213         /// Returns whether the invoice has expired.
1214         #[cfg(feature = "std")]
1215         pub fn is_expired(&self) -> bool {
1216                 Self::is_expired_from_epoch(&self.timestamp(), self.expiry_time())
1217         }
1218
1219         /// Returns whether the expiry time from the given epoch has passed.
1220         #[cfg(feature = "std")]
1221         pub(crate) fn is_expired_from_epoch(epoch: &SystemTime, expiry_time: Duration) -> bool {
1222                 match epoch.elapsed() {
1223                         Ok(elapsed) => elapsed > expiry_time,
1224                         Err(_) => false,
1225                 }
1226         }
1227
1228         /// Returns whether the expiry time would pass at the given point in time.
1229         /// `at_time` is the timestamp as a duration since the Unix epoch.
1230         pub fn would_expire(&self, at_time: Duration) -> bool {
1231                 self.duration_since_epoch()
1232                         .checked_add(self.expiry_time())
1233                         .unwrap_or_else(|| Duration::new(u64::max_value(), 1_000_000_000 - 1)) < at_time
1234         }
1235
1236         /// Returns the invoice's `min_final_cltv_expiry` time, if present, otherwise
1237         /// [`DEFAULT_MIN_FINAL_CLTV_EXPIRY`].
1238         pub fn min_final_cltv_expiry(&self) -> u64 {
1239                 self.signed_invoice.min_final_cltv_expiry()
1240                         .map(|x| x.0)
1241                         .unwrap_or(DEFAULT_MIN_FINAL_CLTV_EXPIRY)
1242         }
1243
1244         /// Returns a list of all fallback addresses
1245         ///
1246         /// (C-not exported) as we don't support Vec<&NonOpaqueType>
1247         pub fn fallbacks(&self) -> Vec<&Fallback> {
1248                 self.signed_invoice.fallbacks()
1249         }
1250
1251         /// Returns a list of all routes included in the invoice
1252         pub fn private_routes(&self) -> Vec<&PrivateRoute> {
1253                 self.signed_invoice.private_routes()
1254         }
1255
1256         /// Returns a list of all routes included in the invoice as the underlying hints
1257         pub fn route_hints(&self) -> Vec<RouteHint> {
1258                 find_all_extract!(
1259                         self.signed_invoice.known_tagged_fields(), TaggedField::PrivateRoute(ref x), x
1260                 ).map(|route| (**route).clone()).collect()
1261         }
1262
1263         /// Returns the currency for which the invoice was issued
1264         pub fn currency(&self) -> Currency {
1265                 self.signed_invoice.currency()
1266         }
1267
1268         /// Returns the amount if specified in the invoice as millisatoshis.
1269         pub fn amount_milli_satoshis(&self) -> Option<u64> {
1270                 self.signed_invoice.amount_pico_btc().map(|v| v / 10)
1271         }
1272
1273         /// Returns the amount if specified in the invoice as pico <currency>.
1274         fn amount_pico_btc(&self) -> Option<u64> {
1275                 self.signed_invoice.amount_pico_btc()
1276         }
1277 }
1278
1279 impl From<TaggedField> for RawTaggedField {
1280         fn from(tf: TaggedField) -> Self {
1281                 RawTaggedField::KnownSemantics(tf)
1282         }
1283 }
1284
1285 impl TaggedField {
1286         /// Numeric representation of the field's tag
1287         pub fn tag(&self) -> u5 {
1288                 let tag = match *self {
1289                         TaggedField::PaymentHash(_) => constants::TAG_PAYMENT_HASH,
1290                         TaggedField::Description(_) => constants::TAG_DESCRIPTION,
1291                         TaggedField::PayeePubKey(_) => constants::TAG_PAYEE_PUB_KEY,
1292                         TaggedField::DescriptionHash(_) => constants::TAG_DESCRIPTION_HASH,
1293                         TaggedField::ExpiryTime(_) => constants::TAG_EXPIRY_TIME,
1294                         TaggedField::MinFinalCltvExpiry(_) => constants::TAG_MIN_FINAL_CLTV_EXPIRY,
1295                         TaggedField::Fallback(_) => constants::TAG_FALLBACK,
1296                         TaggedField::PrivateRoute(_) => constants::TAG_PRIVATE_ROUTE,
1297                         TaggedField::PaymentSecret(_) => constants::TAG_PAYMENT_SECRET,
1298                         TaggedField::Features(_) => constants::TAG_FEATURES,
1299                 };
1300
1301                 u5::try_from_u8(tag).expect("all tags defined are <32")
1302         }
1303 }
1304
1305 impl Description {
1306
1307         /// Creates a new `Description` if `description` is at most 1023 __bytes__ long,
1308         /// returns `CreationError::DescriptionTooLong` otherwise
1309         ///
1310         /// Please note that single characters may use more than one byte due to UTF8 encoding.
1311         pub fn new(description: String) -> Result<Description, CreationError> {
1312                 if description.len() > 639 {
1313                         Err(CreationError::DescriptionTooLong)
1314                 } else {
1315                         Ok(Description(description))
1316                 }
1317         }
1318
1319         /// Returns the underlying description `String`
1320         pub fn into_inner(self) -> String {
1321                 self.0
1322         }
1323 }
1324
1325 impl Into<String> for Description {
1326         fn into(self) -> String {
1327                 self.into_inner()
1328         }
1329 }
1330
1331 impl Deref for Description {
1332         type Target = str;
1333
1334         fn deref(&self) -> &str {
1335                 &self.0
1336         }
1337 }
1338
1339 impl From<PublicKey> for PayeePubKey {
1340         fn from(pk: PublicKey) -> Self {
1341                 PayeePubKey(pk)
1342         }
1343 }
1344
1345 impl Deref for PayeePubKey {
1346         type Target = PublicKey;
1347
1348         fn deref(&self) -> &PublicKey {
1349                 &self.0
1350         }
1351 }
1352
1353 impl ExpiryTime {
1354         /// Construct an `ExpiryTime` from seconds.
1355         pub fn from_seconds(seconds: u64) -> ExpiryTime {
1356                 ExpiryTime(Duration::from_secs(seconds))
1357         }
1358
1359         /// Construct an `ExpiryTime` from a `Duration`.
1360         pub fn from_duration(duration: Duration) -> ExpiryTime {
1361                 ExpiryTime(duration)
1362         }
1363
1364         /// Returns the expiry time in seconds
1365         pub fn as_seconds(&self) -> u64 {
1366                 self.0.as_secs()
1367         }
1368
1369         /// Returns a reference to the underlying `Duration` (=expiry time)
1370         pub fn as_duration(&self) -> &Duration {
1371                 &self.0
1372         }
1373 }
1374
1375 impl PrivateRoute {
1376         /// Creates a new (partial) route from a list of hops
1377         pub fn new(hops: RouteHint) -> Result<PrivateRoute, CreationError> {
1378                 if hops.0.len() <= 12 {
1379                         Ok(PrivateRoute(hops))
1380                 } else {
1381                         Err(CreationError::RouteTooLong)
1382                 }
1383         }
1384
1385         /// Returns the underlying list of hops
1386         pub fn into_inner(self) -> RouteHint {
1387                 self.0
1388         }
1389 }
1390
1391 impl Into<RouteHint> for PrivateRoute {
1392         fn into(self) -> RouteHint {
1393                 self.into_inner()
1394         }
1395 }
1396
1397 impl Deref for PrivateRoute {
1398         type Target = RouteHint;
1399
1400         fn deref(&self) -> &RouteHint {
1401                 &self.0
1402         }
1403 }
1404
1405 impl Deref for InvoiceSignature {
1406         type Target = RecoverableSignature;
1407
1408         fn deref(&self) -> &RecoverableSignature {
1409                 &self.0
1410         }
1411 }
1412
1413 impl Deref for SignedRawInvoice {
1414         type Target = RawInvoice;
1415
1416         fn deref(&self) -> &RawInvoice {
1417                 &self.raw_invoice
1418         }
1419 }
1420
1421 /// Errors that may occur when constructing a new `RawInvoice` or `Invoice`
1422 #[derive(Eq, PartialEq, Debug, Clone)]
1423 pub enum CreationError {
1424         /// The supplied description string was longer than 639 __bytes__ (see [`Description::new(…)`](./struct.Description.html#method.new))
1425         DescriptionTooLong,
1426
1427         /// The specified route has too many hops and can't be encoded
1428         RouteTooLong,
1429
1430         /// The Unix timestamp of the supplied date is less than zero or greater than 35-bits
1431         TimestampOutOfBounds,
1432
1433         /// The supplied millisatoshi amount was greater than the total bitcoin supply.
1434         InvalidAmount,
1435
1436         /// Route hints were required for this invoice and were missing. Applies to
1437         /// [phantom invoices].
1438         ///
1439         /// [phantom invoices]: crate::utils::create_phantom_invoice
1440         MissingRouteHints,
1441 }
1442
1443 impl Display for CreationError {
1444         fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
1445                 match self {
1446                         CreationError::DescriptionTooLong => f.write_str("The supplied description string was longer than 639 bytes"),
1447                         CreationError::RouteTooLong => f.write_str("The specified route has too many hops and can't be encoded"),
1448                         CreationError::TimestampOutOfBounds => f.write_str("The Unix timestamp of the supplied date is less than zero or greater than 35-bits"),
1449                         CreationError::InvalidAmount => f.write_str("The supplied millisatoshi amount was greater than the total bitcoin supply"),
1450                         CreationError::MissingRouteHints => f.write_str("The invoice required route hints and they weren't provided"),
1451                 }
1452         }
1453 }
1454
1455 #[cfg(feature = "std")]
1456 impl std::error::Error for CreationError { }
1457
1458 /// Errors that may occur when converting a `RawInvoice` to an `Invoice`. They relate to the
1459 /// requirements sections in BOLT #11
1460 #[derive(Eq, PartialEq, Debug, Clone)]
1461 pub enum SemanticError {
1462         /// The invoice is missing the mandatory payment hash
1463         NoPaymentHash,
1464
1465         /// The invoice has multiple payment hashes which isn't allowed
1466         MultiplePaymentHashes,
1467
1468         /// No description or description hash are part of the invoice
1469         NoDescription,
1470
1471         /// The invoice contains multiple descriptions and/or description hashes which isn't allowed
1472         MultipleDescriptions,
1473
1474         /// The invoice is missing the mandatory payment secret, which all modern lightning nodes
1475         /// should provide.
1476         NoPaymentSecret,
1477
1478         /// The invoice contains multiple payment secrets
1479         MultiplePaymentSecrets,
1480
1481         /// The invoice's features are invalid
1482         InvalidFeatures,
1483
1484         /// The recovery id doesn't fit the signature/pub key
1485         InvalidRecoveryId,
1486
1487         /// The invoice's signature is invalid
1488         InvalidSignature,
1489
1490         /// The invoice's amount was not a whole number of millisatoshis
1491         ImpreciseAmount,
1492 }
1493
1494 impl Display for SemanticError {
1495         fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
1496                 match self {
1497                         SemanticError::NoPaymentHash => f.write_str("The invoice is missing the mandatory payment hash"),
1498                         SemanticError::MultiplePaymentHashes => f.write_str("The invoice has multiple payment hashes which isn't allowed"),
1499                         SemanticError::NoDescription => f.write_str("No description or description hash are part of the invoice"),
1500                         SemanticError::MultipleDescriptions => f.write_str("The invoice contains multiple descriptions and/or description hashes which isn't allowed"),
1501                         SemanticError::NoPaymentSecret => f.write_str("The invoice is missing the mandatory payment secret"),
1502                         SemanticError::MultiplePaymentSecrets => f.write_str("The invoice contains multiple payment secrets"),
1503                         SemanticError::InvalidFeatures => f.write_str("The invoice's features are invalid"),
1504                         SemanticError::InvalidRecoveryId => f.write_str("The recovery id doesn't fit the signature/pub key"),
1505                         SemanticError::InvalidSignature => f.write_str("The invoice's signature is invalid"),
1506                         SemanticError::ImpreciseAmount => f.write_str("The invoice's amount was not a whole number of millisatoshis"),
1507                 }
1508         }
1509 }
1510
1511 #[cfg(feature = "std")]
1512 impl std::error::Error for SemanticError { }
1513
1514 /// When signing using a fallible method either an user-supplied `SignError` or a `CreationError`
1515 /// may occur.
1516 #[derive(Eq, PartialEq, Debug, Clone)]
1517 pub enum SignOrCreationError<S = ()> {
1518         /// An error occurred during signing
1519         SignError(S),
1520
1521         /// An error occurred while building the transaction
1522         CreationError(CreationError),
1523 }
1524
1525 impl<S> Display for SignOrCreationError<S> {
1526         fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
1527                 match self {
1528                         SignOrCreationError::SignError(_) => f.write_str("An error occurred during signing"),
1529                         SignOrCreationError::CreationError(err) => err.fmt(f),
1530                 }
1531         }
1532 }
1533
1534 #[cfg(feature = "serde")]
1535 impl Serialize for Invoice {
1536         fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: Serializer {
1537                 serializer.serialize_str(self.to_string().as_str())
1538         }
1539 }
1540 #[cfg(feature = "serde")]
1541 impl<'de> Deserialize<'de> for Invoice {
1542         fn deserialize<D>(deserializer: D) -> Result<Invoice, D::Error> where D: Deserializer<'de> {
1543                 let bolt11 = String::deserialize(deserializer)?
1544                         .parse::<Invoice>()
1545                         .map_err(|e| D::Error::custom(format!("{:?}", e)))?;
1546
1547                 Ok(bolt11)
1548         }
1549 }
1550
1551 #[cfg(test)]
1552 mod test {
1553         use bitcoin_hashes::hex::FromHex;
1554         use bitcoin_hashes::sha256;
1555
1556         #[test]
1557         fn test_system_time_bounds_assumptions() {
1558                 assert_eq!(
1559                         ::PositiveTimestamp::from_unix_timestamp(::MAX_TIMESTAMP + 1),
1560                         Err(::CreationError::TimestampOutOfBounds)
1561                 );
1562         }
1563
1564         #[test]
1565         fn test_calc_invoice_hash() {
1566                 use ::{RawInvoice, RawHrp, RawDataPart, Currency, PositiveTimestamp};
1567                 use ::TaggedField::*;
1568
1569                 let invoice = RawInvoice {
1570                         hrp: RawHrp {
1571                                 currency: Currency::Bitcoin,
1572                                 raw_amount: None,
1573                                 si_prefix: None,
1574                         },
1575                         data: RawDataPart {
1576                                 timestamp: PositiveTimestamp::from_unix_timestamp(1496314658).unwrap(),
1577                                 tagged_fields: vec![
1578                                         PaymentHash(::Sha256(sha256::Hash::from_hex(
1579                                                 "0001020304050607080900010203040506070809000102030405060708090102"
1580                                         ).unwrap())).into(),
1581                                         Description(::Description::new(
1582                                                 "Please consider supporting this project".to_owned()
1583                                         ).unwrap()).into(),
1584                                 ],
1585                         },
1586                 };
1587
1588                 let expected_hash = [
1589                         0xc3, 0xd4, 0xe8, 0x3f, 0x64, 0x6f, 0xa7, 0x9a, 0x39, 0x3d, 0x75, 0x27, 0x7b, 0x1d,
1590                         0x85, 0x8d, 0xb1, 0xd1, 0xf7, 0xab, 0x71, 0x37, 0xdc, 0xb7, 0x83, 0x5d, 0xb2, 0xec,
1591                         0xd5, 0x18, 0xe1, 0xc9
1592                 ];
1593
1594                 assert_eq!(invoice.signable_hash(), expected_hash)
1595         }
1596
1597         #[test]
1598         fn test_check_signature() {
1599                 use TaggedField::*;
1600                 use secp256k1::Secp256k1;
1601                 use secp256k1::ecdsa::{RecoveryId, RecoverableSignature};
1602                 use secp256k1::{SecretKey, PublicKey};
1603                 use {SignedRawInvoice, InvoiceSignature, RawInvoice, RawHrp, RawDataPart, Currency, Sha256,
1604                          PositiveTimestamp};
1605
1606                 let invoice = SignedRawInvoice {
1607                         raw_invoice: RawInvoice {
1608                                 hrp: RawHrp {
1609                                         currency: Currency::Bitcoin,
1610                                         raw_amount: None,
1611                                         si_prefix: None,
1612                                 },
1613                                 data: RawDataPart {
1614                                         timestamp: PositiveTimestamp::from_unix_timestamp(1496314658).unwrap(),
1615                                         tagged_fields: vec ! [
1616                                                 PaymentHash(Sha256(sha256::Hash::from_hex(
1617                                                         "0001020304050607080900010203040506070809000102030405060708090102"
1618                                                 ).unwrap())).into(),
1619                                                 Description(
1620                                                         ::Description::new(
1621                                                                 "Please consider supporting this project".to_owned()
1622                                                         ).unwrap()
1623                                                 ).into(),
1624                                         ],
1625                                 },
1626                         },
1627                         hash: [
1628                                 0xc3, 0xd4, 0xe8, 0x3f, 0x64, 0x6f, 0xa7, 0x9a, 0x39, 0x3d, 0x75, 0x27,
1629                                 0x7b, 0x1d, 0x85, 0x8d, 0xb1, 0xd1, 0xf7, 0xab, 0x71, 0x37, 0xdc, 0xb7,
1630                                 0x83, 0x5d, 0xb2, 0xec, 0xd5, 0x18, 0xe1, 0xc9
1631                         ],
1632                         signature: InvoiceSignature(RecoverableSignature::from_compact(
1633                                 & [
1634                                         0x38u8, 0xec, 0x68, 0x91, 0x34, 0x5e, 0x20, 0x41, 0x45, 0xbe, 0x8a,
1635                                         0x3a, 0x99, 0xde, 0x38, 0xe9, 0x8a, 0x39, 0xd6, 0xa5, 0x69, 0x43,
1636                                         0x4e, 0x18, 0x45, 0xc8, 0xaf, 0x72, 0x05, 0xaf, 0xcf, 0xcc, 0x7f,
1637                                         0x42, 0x5f, 0xcd, 0x14, 0x63, 0xe9, 0x3c, 0x32, 0x88, 0x1e, 0xad,
1638                                         0x0d, 0x6e, 0x35, 0x6d, 0x46, 0x7e, 0xc8, 0xc0, 0x25, 0x53, 0xf9,
1639                                         0xaa, 0xb1, 0x5e, 0x57, 0x38, 0xb1, 0x1f, 0x12, 0x7f
1640                                 ],
1641                                 RecoveryId::from_i32(0).unwrap()
1642                         ).unwrap()),
1643                 };
1644
1645                 assert!(invoice.check_signature());
1646
1647                 let private_key = SecretKey::from_slice(
1648                         &[
1649                                 0xe1, 0x26, 0xf6, 0x8f, 0x7e, 0xaf, 0xcc, 0x8b, 0x74, 0xf5, 0x4d, 0x26, 0x9f, 0xe2,
1650                                 0x06, 0xbe, 0x71, 0x50, 0x00, 0xf9, 0x4d, 0xac, 0x06, 0x7d, 0x1c, 0x04, 0xa8, 0xca,
1651                                 0x3b, 0x2d, 0xb7, 0x34
1652                         ][..]
1653                 ).unwrap();
1654                 let public_key = PublicKey::from_secret_key(&Secp256k1::new(), &private_key);
1655
1656                 assert_eq!(invoice.recover_payee_pub_key(), Ok(::PayeePubKey(public_key)));
1657
1658                 let (raw_invoice, _, _) = invoice.into_parts();
1659                 let new_signed = raw_invoice.sign::<_, ()>(|hash| {
1660                         Ok(Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key))
1661                 }).unwrap();
1662
1663                 assert!(new_signed.check_signature());
1664         }
1665
1666         #[test]
1667         fn test_check_feature_bits() {
1668                 use TaggedField::*;
1669                 use lightning::ln::features::InvoiceFeatures;
1670                 use secp256k1::Secp256k1;
1671                 use secp256k1::SecretKey;
1672                 use {RawInvoice, RawHrp, RawDataPart, Currency, Sha256, PositiveTimestamp, Invoice,
1673                          SemanticError};
1674
1675                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
1676                 let payment_secret = lightning::ln::PaymentSecret([21; 32]);
1677                 let invoice_template = RawInvoice {
1678                         hrp: RawHrp {
1679                                 currency: Currency::Bitcoin,
1680                                 raw_amount: None,
1681                                 si_prefix: None,
1682                         },
1683                         data: RawDataPart {
1684                                 timestamp: PositiveTimestamp::from_unix_timestamp(1496314658).unwrap(),
1685                                 tagged_fields: vec ! [
1686                                         PaymentHash(Sha256(sha256::Hash::from_hex(
1687                                                 "0001020304050607080900010203040506070809000102030405060708090102"
1688                                         ).unwrap())).into(),
1689                                         Description(
1690                                                 ::Description::new(
1691                                                         "Please consider supporting this project".to_owned()
1692                                                 ).unwrap()
1693                                         ).into(),
1694                                 ],
1695                         },
1696                 };
1697
1698                 // Missing features
1699                 let invoice = {
1700                         let mut invoice = invoice_template.clone();
1701                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1702                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)))
1703                 }.unwrap();
1704                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::InvalidFeatures));
1705
1706                 // Missing feature bits
1707                 let invoice = {
1708                         let mut invoice = invoice_template.clone();
1709                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1710                         invoice.data.tagged_fields.push(Features(InvoiceFeatures::empty()).into());
1711                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)))
1712                 }.unwrap();
1713                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::InvalidFeatures));
1714
1715                 // Including payment secret and feature bits
1716                 let invoice = {
1717                         let mut invoice = invoice_template.clone();
1718                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1719                         invoice.data.tagged_fields.push(Features(InvoiceFeatures::known()).into());
1720                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)))
1721                 }.unwrap();
1722                 assert!(Invoice::from_signed(invoice).is_ok());
1723
1724                 // No payment secret or features
1725                 let invoice = {
1726                         let invoice = invoice_template.clone();
1727                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)))
1728                 }.unwrap();
1729                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::NoPaymentSecret));
1730
1731                 // No payment secret or feature bits
1732                 let invoice = {
1733                         let mut invoice = invoice_template.clone();
1734                         invoice.data.tagged_fields.push(Features(InvoiceFeatures::empty()).into());
1735                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)))
1736                 }.unwrap();
1737                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::NoPaymentSecret));
1738
1739                 // Missing payment secret
1740                 let invoice = {
1741                         let mut invoice = invoice_template.clone();
1742                         invoice.data.tagged_fields.push(Features(InvoiceFeatures::known()).into());
1743                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)))
1744                 }.unwrap();
1745                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::NoPaymentSecret));
1746
1747                 // Multiple payment secrets
1748                 let invoice = {
1749                         let mut invoice = invoice_template.clone();
1750                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1751                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1752                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_ecdsa_recoverable(hash, &private_key)))
1753                 }.unwrap();
1754                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::MultiplePaymentSecrets));
1755         }
1756
1757         #[test]
1758         fn test_builder_amount() {
1759                 use ::*;
1760
1761                 let builder = InvoiceBuilder::new(Currency::Bitcoin)
1762                         .description("Test".into())
1763                         .payment_hash(sha256::Hash::from_slice(&[0;32][..]).unwrap())
1764                         .duration_since_epoch(Duration::from_secs(1234567));
1765
1766                 let invoice = builder.clone()
1767                         .amount_milli_satoshis(1500)
1768                         .build_raw()
1769                         .unwrap();
1770
1771                 assert_eq!(invoice.hrp.si_prefix, Some(SiPrefix::Nano));
1772                 assert_eq!(invoice.hrp.raw_amount, Some(15));
1773
1774
1775                 let invoice = builder.clone()
1776                         .amount_milli_satoshis(150)
1777                         .build_raw()
1778                         .unwrap();
1779
1780                 assert_eq!(invoice.hrp.si_prefix, Some(SiPrefix::Pico));
1781                 assert_eq!(invoice.hrp.raw_amount, Some(1500));
1782         }
1783
1784         #[test]
1785         fn test_builder_fail() {
1786                 use ::*;
1787                 use lightning::routing::router::RouteHintHop;
1788                 use std::iter::FromIterator;
1789                 use secp256k1::PublicKey;
1790
1791                 let builder = InvoiceBuilder::new(Currency::Bitcoin)
1792                         .payment_hash(sha256::Hash::from_slice(&[0;32][..]).unwrap())
1793                         .duration_since_epoch(Duration::from_secs(1234567))
1794                         .min_final_cltv_expiry(144);
1795
1796                 let too_long_string = String::from_iter(
1797                         (0..1024).map(|_| '?')
1798                 );
1799
1800                 let long_desc_res = builder.clone()
1801                         .description(too_long_string)
1802                         .build_raw();
1803                 assert_eq!(long_desc_res, Err(CreationError::DescriptionTooLong));
1804
1805                 let route_hop = RouteHintHop {
1806                         src_node_id: PublicKey::from_slice(
1807                                         &[
1808                                                 0x03, 0x9e, 0x03, 0xa9, 0x01, 0xb8, 0x55, 0x34, 0xff, 0x1e, 0x92, 0xc4,
1809                                                 0x3c, 0x74, 0x43, 0x1f, 0x7c, 0xe7, 0x20, 0x46, 0x06, 0x0f, 0xcf, 0x7a,
1810                                                 0x95, 0xc3, 0x7e, 0x14, 0x8f, 0x78, 0xc7, 0x72, 0x55
1811                                         ][..]
1812                                 ).unwrap(),
1813                         short_channel_id: 0,
1814                         fees: RoutingFees {
1815                                 base_msat: 0,
1816                                 proportional_millionths: 0,
1817                         },
1818                         cltv_expiry_delta: 0,
1819                         htlc_minimum_msat: None,
1820                         htlc_maximum_msat: None,
1821                 };
1822                 let too_long_route = RouteHint(vec![route_hop; 13]);
1823                 let long_route_res = builder.clone()
1824                         .description("Test".into())
1825                         .private_route(too_long_route)
1826                         .build_raw();
1827                 assert_eq!(long_route_res, Err(CreationError::RouteTooLong));
1828
1829                 let sign_error_res = builder.clone()
1830                         .description("Test".into())
1831                         .payment_secret(PaymentSecret([0; 32]))
1832                         .try_build_signed(|_| {
1833                                 Err("ImaginaryError")
1834                         });
1835                 assert_eq!(sign_error_res, Err(SignOrCreationError::SignError("ImaginaryError")));
1836         }
1837
1838         #[test]
1839         fn test_builder_ok() {
1840                 use ::*;
1841                 use lightning::routing::router::RouteHintHop;
1842                 use secp256k1::Secp256k1;
1843                 use secp256k1::{SecretKey, PublicKey};
1844                 use std::time::{UNIX_EPOCH, Duration};
1845
1846                 let secp_ctx = Secp256k1::new();
1847
1848                 let private_key = SecretKey::from_slice(
1849                         &[
1850                                 0xe1, 0x26, 0xf6, 0x8f, 0x7e, 0xaf, 0xcc, 0x8b, 0x74, 0xf5, 0x4d, 0x26, 0x9f, 0xe2,
1851                                 0x06, 0xbe, 0x71, 0x50, 0x00, 0xf9, 0x4d, 0xac, 0x06, 0x7d, 0x1c, 0x04, 0xa8, 0xca,
1852                                 0x3b, 0x2d, 0xb7, 0x34
1853                         ][..]
1854                 ).unwrap();
1855                 let public_key = PublicKey::from_secret_key(&secp_ctx, &private_key);
1856
1857                 let route_1 = RouteHint(vec![
1858                         RouteHintHop {
1859                                 src_node_id: public_key.clone(),
1860                                 short_channel_id: de::parse_int_be(&[123; 8], 256).expect("short chan ID slice too big?"),
1861                                 fees: RoutingFees {
1862                                         base_msat: 2,
1863                                         proportional_millionths: 1,
1864                                 },
1865                                 cltv_expiry_delta: 145,
1866                                 htlc_minimum_msat: None,
1867                                 htlc_maximum_msat: None,
1868                         },
1869                         RouteHintHop {
1870                                 src_node_id: public_key.clone(),
1871                                 short_channel_id: de::parse_int_be(&[42; 8], 256).expect("short chan ID slice too big?"),
1872                                 fees: RoutingFees {
1873                                         base_msat: 3,
1874                                         proportional_millionths: 2,
1875                                 },
1876                                 cltv_expiry_delta: 146,
1877                                 htlc_minimum_msat: None,
1878                                 htlc_maximum_msat: None,
1879                         }
1880                 ]);
1881
1882                 let route_2 = RouteHint(vec![
1883                         RouteHintHop {
1884                                 src_node_id: public_key.clone(),
1885                                 short_channel_id: 0,
1886                                 fees: RoutingFees {
1887                                         base_msat: 4,
1888                                         proportional_millionths: 3,
1889                                 },
1890                                 cltv_expiry_delta: 147,
1891                                 htlc_minimum_msat: None,
1892                                 htlc_maximum_msat: None,
1893                         },
1894                         RouteHintHop {
1895                                 src_node_id: public_key.clone(),
1896                                 short_channel_id: de::parse_int_be(&[1; 8], 256).expect("short chan ID slice too big?"),
1897                                 fees: RoutingFees {
1898                                         base_msat: 5,
1899                                         proportional_millionths: 4,
1900                                 },
1901                                 cltv_expiry_delta: 148,
1902                                 htlc_minimum_msat: None,
1903                                 htlc_maximum_msat: None,
1904                         }
1905                 ]);
1906
1907                 let builder = InvoiceBuilder::new(Currency::BitcoinTestnet)
1908                         .amount_milli_satoshis(123)
1909                         .duration_since_epoch(Duration::from_secs(1234567))
1910                         .payee_pub_key(public_key.clone())
1911                         .expiry_time(Duration::from_secs(54321))
1912                         .min_final_cltv_expiry(144)
1913                         .fallback(Fallback::PubKeyHash([0;20]))
1914                         .private_route(route_1.clone())
1915                         .private_route(route_2.clone())
1916                         .description_hash(sha256::Hash::from_slice(&[3;32][..]).unwrap())
1917                         .payment_hash(sha256::Hash::from_slice(&[21;32][..]).unwrap())
1918                         .payment_secret(PaymentSecret([42; 32]))
1919                         .basic_mpp();
1920
1921                 let invoice = builder.clone().build_signed(|hash| {
1922                         secp_ctx.sign_ecdsa_recoverable(hash, &private_key)
1923                 }).unwrap();
1924
1925                 assert!(invoice.check_signature().is_ok());
1926                 assert_eq!(invoice.tagged_fields().count(), 10);
1927
1928                 assert_eq!(invoice.amount_milli_satoshis(), Some(123));
1929                 assert_eq!(invoice.amount_pico_btc(), Some(1230));
1930                 assert_eq!(invoice.currency(), Currency::BitcoinTestnet);
1931                 #[cfg(feature = "std")]
1932                 assert_eq!(
1933                         invoice.timestamp().duration_since(UNIX_EPOCH).unwrap().as_secs(),
1934                         1234567
1935                 );
1936                 assert_eq!(invoice.payee_pub_key(), Some(&public_key));
1937                 assert_eq!(invoice.expiry_time(), Duration::from_secs(54321));
1938                 assert_eq!(invoice.min_final_cltv_expiry(), 144);
1939                 assert_eq!(invoice.fallbacks(), vec![&Fallback::PubKeyHash([0;20])]);
1940                 assert_eq!(invoice.private_routes(), vec![&PrivateRoute(route_1), &PrivateRoute(route_2)]);
1941                 assert_eq!(
1942                         invoice.description(),
1943                         InvoiceDescription::Hash(&Sha256(sha256::Hash::from_slice(&[3;32][..]).unwrap()))
1944                 );
1945                 assert_eq!(invoice.payment_hash(), &sha256::Hash::from_slice(&[21;32][..]).unwrap());
1946                 assert_eq!(invoice.payment_secret(), &PaymentSecret([42; 32]));
1947                 assert_eq!(invoice.features(), Some(&InvoiceFeatures::known()));
1948
1949                 let raw_invoice = builder.build_raw().unwrap();
1950                 assert_eq!(raw_invoice, *invoice.into_signed_raw().raw_invoice())
1951         }
1952
1953         #[test]
1954         fn test_default_values() {
1955                 use ::*;
1956                 use secp256k1::Secp256k1;
1957                 use secp256k1::SecretKey;
1958
1959                 let signed_invoice = InvoiceBuilder::new(Currency::Bitcoin)
1960                         .description("Test".into())
1961                         .payment_hash(sha256::Hash::from_slice(&[0;32][..]).unwrap())
1962                         .payment_secret(PaymentSecret([0; 32]))
1963                         .duration_since_epoch(Duration::from_secs(1234567))
1964                         .build_raw()
1965                         .unwrap()
1966                         .sign::<_, ()>(|hash| {
1967                                 let privkey = SecretKey::from_slice(&[41; 32]).unwrap();
1968                                 let secp_ctx = Secp256k1::new();
1969                                 Ok(secp_ctx.sign_ecdsa_recoverable(hash, &privkey))
1970                         })
1971                         .unwrap();
1972                 let invoice = Invoice::from_signed(signed_invoice).unwrap();
1973
1974                 assert_eq!(invoice.min_final_cltv_expiry(), DEFAULT_MIN_FINAL_CLTV_EXPIRY);
1975                 assert_eq!(invoice.expiry_time(), Duration::from_secs(DEFAULT_EXPIRY_TIME));
1976                 assert!(!invoice.would_expire(Duration::from_secs(1234568)));
1977         }
1978
1979         #[test]
1980         fn test_expiration() {
1981                 use ::*;
1982                 use secp256k1::Secp256k1;
1983                 use secp256k1::SecretKey;
1984
1985                 let signed_invoice = InvoiceBuilder::new(Currency::Bitcoin)
1986                         .description("Test".into())
1987                         .payment_hash(sha256::Hash::from_slice(&[0;32][..]).unwrap())
1988                         .payment_secret(PaymentSecret([0; 32]))
1989                         .duration_since_epoch(Duration::from_secs(1234567))
1990                         .build_raw()
1991                         .unwrap()
1992                         .sign::<_, ()>(|hash| {
1993                                 let privkey = SecretKey::from_slice(&[41; 32]).unwrap();
1994                                 let secp_ctx = Secp256k1::new();
1995                                 Ok(secp_ctx.sign_ecdsa_recoverable(hash, &privkey))
1996                         })
1997                         .unwrap();
1998                 let invoice = Invoice::from_signed(signed_invoice).unwrap();
1999
2000                 assert!(invoice.would_expire(Duration::from_secs(1234567 + DEFAULT_EXPIRY_TIME + 1)));
2001         }
2002
2003         #[cfg(feature = "serde")]
2004         #[test]
2005         fn test_serde() {
2006                 let invoice_str = "lnbc100p1psj9jhxdqud3jxktt5w46x7unfv9kz6mn0v3jsnp4q0d3p2sfluzdx45tqcs\
2007                         h2pu5qc7lgq0xs578ngs6s0s68ua4h7cvspp5q6rmq35js88zp5dvwrv9m459tnk2zunwj5jalqtyxqulh0l\
2008                         5gflssp5nf55ny5gcrfl30xuhzj3nphgj27rstekmr9fw3ny5989s300gyus9qyysgqcqpcrzjqw2sxwe993\
2009                         h5pcm4dxzpvttgza8zhkqxpgffcrf5v25nwpr3cmfg7z54kuqq8rgqqqqqqqq2qqqqq9qq9qrzjqd0ylaqcl\
2010                         j9424x9m8h2vcukcgnm6s56xfgu3j78zyqzhgs4hlpzvznlugqq9vsqqqqqqqlgqqqqqeqq9qrzjqwldmj9d\
2011                         ha74df76zhx6l9we0vjdquygcdt3kssupehe64g6yyp5yz5rhuqqwccqqyqqqqlgqqqqjcqq9qrzjqf9e58a\
2012                         guqr0rcun0ajlvmzq3ek63cw2w282gv3z5uupmuwvgjtq2z55qsqqg6qqqyqqqrtnqqqzq3cqygrzjqvphms\
2013                         ywntrrhqjcraumvc4y6r8v4z5v593trte429v4hredj7ms5z52usqq9ngqqqqqqqlgqqqqqqgq9qrzjq2v0v\
2014                         p62g49p7569ev48cmulecsxe59lvaw3wlxm7r982zxa9zzj7z5l0cqqxusqqyqqqqlgqqqqqzsqygarl9fh3\
2015                         8s0gyuxjjgux34w75dnc6xp2l35j7es3jd4ugt3lu0xzre26yg5m7ke54n2d5sym4xcmxtl8238xxvw5h5h5\
2016                         j5r6drg6k6zcqj0fcwg";
2017                 let invoice = invoice_str.parse::<super::Invoice>().unwrap();
2018                 let serialized_invoice = serde_json::to_string(&invoice).unwrap();
2019                 let deserialized_invoice: super::Invoice = serde_json::from_str(serialized_invoice.as_str()).unwrap();
2020                 assert_eq!(invoice, deserialized_invoice);
2021                 assert_eq!(invoice_str, deserialized_invoice.to_string().as_str());
2022                 assert_eq!(invoice_str, serialized_invoice.as_str().trim_matches('\"'));
2023         }
2024 }