_ Git - rust-lightning/blob - lightning-invoice/src/lib.rs

   1 #![deny(missing_docs)]
   2 #![deny(non_upper_case_globals)]
   3 #![deny(non_camel_case_types)]
   4 #![deny(non_snake_case)]
   5 #![deny(unused_mut)]
   6 #![deny(broken_intra_doc_links)]
   7
   8 #![cfg_attr(feature = "strict", deny(warnings))]
   9
  10 //! This crate provides data structures to represent
  11 //! [lightning BOLT11](https://github.com/lightningnetwork/lightning-rfc/blob/master/11-payment-encoding.md)
  12 //! invoices and functions to create, encode and decode these. If you just want to use the standard
  13 //! en-/decoding functionality this should get you started:
  14 //!
  15 //!   * For parsing use `str::parse::<Invoice>(&self)` (see the docs of `impl FromStr for Invoice`)
  16 //!   * For constructing invoices use the `InvoiceBuilder`
  17 //!   * For serializing invoices use the `Display`/`ToString` traits
  18 pub mod utils;
  19
  20 extern crate bech32;
  21 extern crate bitcoin_hashes;
  22 extern crate lightning;
  23 extern crate num_traits;
  24 extern crate secp256k1;
  25
  26 use bech32::u5;
  27 use bitcoin_hashes::Hash;
  28 use bitcoin_hashes::sha256;
  29 use lightning::ln::PaymentSecret;
  30 use lightning::ln::features::InvoiceFeatures;
  31 #[cfg(any(doc, test))]
  32 use lightning::routing::network_graph::RoutingFees;
  33 use lightning::routing::router::RouteHintHop;
  34
  35 use secp256k1::key::PublicKey;
  36 use secp256k1::{Message, Secp256k1};
  37 use secp256k1::recovery::RecoverableSignature;
  38
  39 use std::fmt::{Display, Formatter, self};
  40 use std::iter::FilterMap;
  41 use std::ops::Deref;
  42 use std::slice::Iter;
  43 use std::time::{SystemTime, Duration, UNIX_EPOCH};
  44
  45 mod de;
  46 mod ser;
  47 mod tb;
  48
  49 pub use de::{ParseError, ParseOrSemanticError};
  50
  51 // TODO: fix before 2037 (see rust PR #55527)
  52 /// Defines the maximum UNIX timestamp that can be represented as `SystemTime`. This is checked by
  53 /// one of the unit tests, please run them.
  54 const SYSTEM_TIME_MAX_UNIX_TIMESTAMP: u64 = std::i32::MAX as u64;
  55
  56 /// Allow the expiry time to be up to one year. Since this reduces the range of possible timestamps
  57 /// it should be rather low as long as we still have to support 32bit time representations
  58 const MAX_EXPIRY_TIME: u64 = 60 * 60 * 24 * 356;
  59
  60 /// Default expiry time as defined by [BOLT 11].
  61 ///
  62 /// [BOLT 11]: https://github.com/lightningnetwork/lightning-rfc/blob/master/11-payment-encoding.md
  63 const DEFAULT_EXPIRY_TIME: u64 = 3600;
  64
  65 /// Default minimum final CLTV expiry as defined by [BOLT 11].
  66 ///
  67 /// [BOLT 11]: https://github.com/lightningnetwork/lightning-rfc/blob/master/11-payment-encoding.md
  68 const DEFAULT_MIN_FINAL_CLTV_EXPIRY: u64 = 18;
  69
  70 /// This function is used as a static assert for the size of `SystemTime`. If the crate fails to
  71 /// compile due to it this indicates that your system uses unexpected bounds for `SystemTime`. You
  72 /// can remove this functions and run the test `test_system_time_bounds_assumptions`. In any case,
  73 /// please open an issue. If all tests pass you should be able to use this library safely by just
  74 /// removing this function till we patch it accordingly.
  75 fn __system_time_size_check() {
  76         // Use 2 * sizeof(u64) as expected size since the expected underlying implementation is storing
  77         // a `Duration` since `SystemTime::UNIX_EPOCH`.
  78         unsafe { std::mem::transmute_copy::<SystemTime, [u8; 16]>(&UNIX_EPOCH); }
  79 }
  80
  81
  82 /// **Call this function on startup to ensure that all assumptions about the platform are valid.**
  83 ///
  84 /// Unfortunately we have to make assumptions about the upper bounds of the `SystemTime` type on
  85 /// your platform which we can't fully verify at compile time and which isn't part of it's contract.
  86 /// To our best knowledge our assumptions hold for all platforms officially supported by rust, but
  87 /// since this check is fast we recommend to do it anyway.
  88 ///
  89 /// If this function fails this is considered a bug. Please open an issue describing your
  90 /// platform and stating your current system time.
  91 ///
  92 /// # Panics
  93 /// If the check fails this function panics. By calling this function on startup you ensure that
  94 /// this wont happen at an arbitrary later point in time.
  95 pub fn check_platform() {
  96     // The upper and lower bounds of `SystemTime` are not part of its public contract and are
  97     // platform specific. That's why we have to test if our assumptions regarding these bounds
  98     // hold on the target platform.
  99     //
 100     // If this test fails on your platform, please don't use the library and open an issue
 101     // instead so we can resolve the situation. Currently this library is tested on:
 102     //   * Linux (64bit)
 103     let fail_date = UNIX_EPOCH + Duration::from_secs(SYSTEM_TIME_MAX_UNIX_TIMESTAMP);
 104     let year = Duration::from_secs(60 * 60 * 24 * 365);
 105
 106     // Make sure that the library will keep working for another year
 107     assert!(fail_date.duration_since(SystemTime::now()).unwrap() > year);
 108
 109     let max_ts = PositiveTimestamp::from_unix_timestamp(
 110         SYSTEM_TIME_MAX_UNIX_TIMESTAMP - MAX_EXPIRY_TIME
 111     ).unwrap();
 112     let max_exp = ::ExpiryTime::from_seconds(MAX_EXPIRY_TIME).unwrap();
 113
 114     assert_eq!(
 115         (*max_ts.as_time() + *max_exp.as_duration()).duration_since(UNIX_EPOCH).unwrap().as_secs(),
 116         SYSTEM_TIME_MAX_UNIX_TIMESTAMP
 117     );
 118 }
 119
 120
 121 /// Builder for `Invoice`s. It's the most convenient and advised way to use this library. It ensures
 122 /// that only a semantically and syntactically correct Invoice can be built using it.
 123 ///
 124 /// ```
 125 /// extern crate secp256k1;
 126 /// extern crate lightning_invoice;
 127 /// extern crate bitcoin_hashes;
 128 ///
 129 /// use bitcoin_hashes::Hash;
 130 /// use bitcoin_hashes::sha256;
 131 ///
 132 /// use secp256k1::Secp256k1;
 133 /// use secp256k1::key::SecretKey;
 134 ///
 135 /// use lightning_invoice::{Currency, InvoiceBuilder};
 136 ///
 137 /// # fn main() {
 138 /// let private_key = SecretKey::from_slice(
 139 ///             &[
 140 ///                     0xe1, 0x26, 0xf6, 0x8f, 0x7e, 0xaf, 0xcc, 0x8b, 0x74, 0xf5, 0x4d, 0x26, 0x9f,
 141 ///                     0xe2, 0x06, 0xbe, 0x71, 0x50, 0x00, 0xf9, 0x4d, 0xac, 0x06, 0x7d, 0x1c, 0x04,
 142 ///             0xa8, 0xca, 0x3b, 0x2d, 0xb7, 0x34
 143 ///     ][..]
 144 ///     ).unwrap();
 145 ///
 146 /// let payment_hash = sha256::Hash::from_slice(&[0; 32][..]).unwrap();
 147 ///
 148 /// let invoice = InvoiceBuilder::new(Currency::Bitcoin)
 149 ///     .description("Coins pls!".into())
 150 ///     .payment_hash(payment_hash)
 151 ///     .current_timestamp()
 152 ///     .min_final_cltv_expiry(144)
 153 ///     .build_signed(|hash| {
 154 ///             Secp256k1::new().sign_recoverable(hash, &private_key)
 155 ///     })
 156 ///     .unwrap();
 157 ///
 158 /// assert!(invoice.to_string().starts_with("lnbc1"));
 159 /// # }
 160 /// ```
 161 ///
 162 /// # Type parameters
 163 /// The two parameters `D` and `H` signal if the builder already contains the correct amount of the
 164 /// given field:
 165 ///  * `D`: exactly one `Description` or `DescriptionHash`
 166 ///  * `H`: exactly one `PaymentHash`
 167 ///  * `T`: the timestamp is set
 168 ///
 169 /// (C-not exported) as we likely need to manually select one set of boolean type parameters.
 170 #[derive(Eq, PartialEq, Debug, Clone)]
 171 pub struct InvoiceBuilder<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> {
 172         currency: Currency,
 173         amount: Option<u64>,
 174         si_prefix: Option<SiPrefix>,
 175         timestamp: Option<PositiveTimestamp>,
 176         tagged_fields: Vec<TaggedField>,
 177         error: Option<CreationError>,
 178
 179         phantom_d: std::marker::PhantomData<D>,
 180         phantom_h: std::marker::PhantomData<H>,
 181         phantom_t: std::marker::PhantomData<T>,
 182         phantom_c: std::marker::PhantomData<C>,
 183         phantom_s: std::marker::PhantomData<S>,
 184 }
 185
 186 /// Represents a syntactically and semantically correct lightning BOLT11 invoice.
 187 ///
 188 /// There are three ways to construct an `Invoice`:
 189 ///  1. using `InvoiceBuilder`
 190 ///  2. using `Invoice::from_signed(SignedRawInvoice)`
 191 ///  3. using `str::parse::<Invoice>(&str)`
 192 #[derive(Eq, PartialEq, Debug, Clone)]
 193 pub struct Invoice {
 194         signed_invoice: SignedRawInvoice,
 195 }
 196
 197 /// Represents the description of an invoice which has to be either a directly included string or
 198 /// a hash of a description provided out of band.
 199 ///
 200 /// (C-not exported) As we don't have a good way to map the reference lifetimes making this
 201 /// practically impossible to use safely in languages like C.
 202 #[derive(Eq, PartialEq, Debug, Clone)]
 203 pub enum InvoiceDescription<'f> {
 204         /// Reference to the directly supplied description in the invoice
 205         Direct(&'f Description),
 206
 207         /// Reference to the description's hash included in the invoice
 208         Hash(&'f Sha256),
 209 }
 210
 211 /// Represents a signed `RawInvoice` with cached hash. The signature is not checked and may be
 212 /// invalid.
 213 ///
 214 /// # Invariants
 215 /// The hash has to be either from the deserialized invoice or from the serialized `raw_invoice`.
 216 #[derive(Eq, PartialEq, Debug, Clone)]
 217 pub struct SignedRawInvoice {
 218         /// The rawInvoice that the signature belongs to
 219         raw_invoice: RawInvoice,
 220
 221         /// Hash of the `RawInvoice` that will be used to check the signature.
 222         ///
 223         /// * if the `SignedRawInvoice` was deserialized the hash is of from the original encoded form,
 224         /// since it's not guaranteed that encoding it again will lead to the same result since integers
 225         /// could have been encoded with leading zeroes etc.
 226         /// * if the `SignedRawInvoice` was constructed manually the hash will be the calculated hash
 227         /// from the `RawInvoice`
 228         hash: [u8; 32],
 229
 230         /// signature of the payment request
 231         signature: InvoiceSignature,
 232 }
 233
 234 /// Represents an syntactically correct Invoice for a payment on the lightning network,
 235 /// but without the signature information.
 236 /// De- and encoding should not lead to information loss but may lead to different hashes.
 237 ///
 238 /// For methods without docs see the corresponding methods in `Invoice`.
 239 #[derive(Eq, PartialEq, Debug, Clone)]
 240 pub struct RawInvoice {
 241         /// human readable part
 242         pub hrp: RawHrp,
 243
 244         /// data part
 245         pub data: RawDataPart,
 246 }
 247
 248 /// Data of the `RawInvoice` that is encoded in the human readable part
 249 ///
 250 /// (C-not exported) As we don't yet support Option<Enum>
 251 #[derive(Eq, PartialEq, Debug, Clone)]
 252 pub struct RawHrp {
 253         /// The currency deferred from the 3rd and 4th character of the bech32 transaction
 254         pub currency: Currency,
 255
 256         /// The amount that, multiplied by the SI prefix, has to be payed
 257         pub raw_amount: Option<u64>,
 258
 259         /// SI prefix that gets multiplied with the `raw_amount`
 260         pub si_prefix: Option<SiPrefix>,
 261 }
 262
 263 /// Data of the `RawInvoice` that is encoded in the data part
 264 #[derive(Eq, PartialEq, Debug, Clone)]
 265 pub struct RawDataPart {
 266         /// generation time of the invoice
 267         pub timestamp: PositiveTimestamp,
 268
 269         /// tagged fields of the payment request
 270         pub tagged_fields: Vec<RawTaggedField>,
 271 }
 272
 273 /// A timestamp that refers to a date after 1 January 1970 which means its representation as UNIX
 274 /// timestamp is positive.
 275 ///
 276 /// # Invariants
 277 /// The UNIX timestamp representing the stored time has to be positive and small enough so that
 278 /// a `EpiryTime` can be added to it without an overflow.
 279 #[derive(Eq, PartialEq, Debug, Clone)]
 280 pub struct PositiveTimestamp(SystemTime);
 281
 282 /// SI prefixes for the human readable part
 283 #[derive(Eq, PartialEq, Debug, Clone, Copy)]
 284 pub enum SiPrefix {
 285         /// 10^-3
 286         Milli,
 287         /// 10^-6
 288         Micro,
 289         /// 10^-9
 290         Nano,
 291         /// 10^-12
 292         Pico,
 293 }
 294
 295 impl SiPrefix {
 296         /// Returns the multiplier to go from a BTC value to picoBTC implied by this SiPrefix.
 297         /// This is effectively 10^12 * the prefix multiplier
 298         pub fn multiplier(&self) -> u64 {
 299                 match *self {
 300                         SiPrefix::Milli => 1_000_000_000,
 301                         SiPrefix::Micro => 1_000_000,
 302                         SiPrefix::Nano => 1_000,
 303                         SiPrefix::Pico => 1,
 304                 }
 305         }
 306
 307         /// Returns all enum variants of `SiPrefix` sorted in descending order of their associated
 308         /// multiplier.
 309         ///
 310         /// (C-not exported) As we don't yet support a slice of enums, and also because this function
 311         /// isn't the most critical to expose.
 312         pub fn values_desc() -> &'static [SiPrefix] {
 313                 use SiPrefix::*;
 314                 static VALUES: [SiPrefix; 4] = [Milli, Micro, Nano, Pico];
 315                 &VALUES
 316         }
 317 }
 318
 319 /// Enum representing the crypto currencies (or networks) supported by this library
 320 #[derive(Eq, PartialEq, Debug, Clone)]
 321 pub enum Currency {
 322         /// Bitcoin mainnet
 323         Bitcoin,
 324
 325         /// Bitcoin testnet
 326         BitcoinTestnet,
 327
 328         /// Bitcoin regtest
 329         Regtest,
 330
 331         /// Bitcoin simnet
 332         Simnet,
 333
 334         /// Bitcoin signet
 335         Signet,
 336 }
 337
 338 /// Tagged field which may have an unknown tag
 339 ///
 340 /// (C-not exported) as we don't currently support TaggedField
 341 #[derive(Eq, PartialEq, Debug, Clone)]
 342 pub enum RawTaggedField {
 343         /// Parsed tagged field with known tag
 344         KnownSemantics(TaggedField),
 345         /// tagged field which was not parsed due to an unknown tag or undefined field semantics
 346         UnknownSemantics(Vec<u5>),
 347 }
 348
 349 /// Tagged field with known tag
 350 ///
 351 /// For descriptions of the enum values please refer to the enclosed type's docs.
 352 ///
 353 /// (C-not exported) As we don't yet support enum variants with the same name the struct contained
 354 /// in the variant.
 355 #[allow(missing_docs)]
 356 #[derive(Eq, PartialEq, Debug, Clone)]
 357 pub enum TaggedField {
 358         PaymentHash(Sha256),
 359         Description(Description),
 360         PayeePubKey(PayeePubKey),
 361         DescriptionHash(Sha256),
 362         ExpiryTime(ExpiryTime),
 363         MinFinalCltvExpiry(MinFinalCltvExpiry),
 364         Fallback(Fallback),
 365         Route(RouteHint),
 366         PaymentSecret(PaymentSecret),
 367         Features(InvoiceFeatures),
 368 }
 369
 370 /// SHA-256 hash
 371 #[derive(Eq, PartialEq, Debug, Clone)]
 372 pub struct Sha256(pub sha256::Hash);
 373
 374 /// Description string
 375 ///
 376 /// # Invariants
 377 /// The description can be at most 639 __bytes__ long
 378 #[derive(Eq, PartialEq, Debug, Clone)]
 379 pub struct Description(String);
 380
 381 /// Payee public key
 382 #[derive(Eq, PartialEq, Debug, Clone)]
 383 pub struct PayeePubKey(pub PublicKey);
 384
 385 /// Positive duration that defines when (relatively to the timestamp) in the future the invoice
 386 /// expires
 387 ///
 388 /// # Invariants
 389 /// The number of seconds this expiry time represents has to be in the range
 390 /// `0...(SYSTEM_TIME_MAX_UNIX_TIMESTAMP - MAX_EXPIRY_TIME)` to avoid overflows when adding it to a
 391 /// timestamp
 392 #[derive(Eq, PartialEq, Debug, Clone)]
 393 pub struct ExpiryTime(Duration);
 394
 395 /// `min_final_cltv_expiry` to use for the last HTLC in the route
 396 #[derive(Eq, PartialEq, Debug, Clone)]
 397 pub struct MinFinalCltvExpiry(pub u64);
 398
 399 // TODO: better types instead onf byte arrays
 400 /// Fallback address in case no LN payment is possible
 401 #[allow(missing_docs)]
 402 #[derive(Eq, PartialEq, Debug, Clone)]
 403 pub enum Fallback {
 404         SegWitProgram {
 405                 version: u5,
 406                 program: Vec<u8>,
 407         },
 408         PubKeyHash([u8; 20]),
 409         ScriptHash([u8; 20]),
 410 }
 411
 412 /// Recoverable signature
 413 #[derive(Eq, PartialEq, Debug, Clone)]
 414 pub struct InvoiceSignature(pub RecoverableSignature);
 415
 416 /// Private routing information
 417 ///
 418 /// # Invariants
 419 /// The encoded route has to be <1024 5bit characters long (<=639 bytes or <=12 hops)
 420 ///
 421 #[derive(Eq, PartialEq, Debug, Clone)]
 422 pub struct RouteHint(Vec<RouteHintHop>);
 423
 424 /// Tag constants as specified in BOLT11
 425 #[allow(missing_docs)]
 426 pub mod constants {
 427         pub const TAG_PAYMENT_HASH: u8 = 1;
 428         pub const TAG_DESCRIPTION: u8 = 13;
 429         pub const TAG_PAYEE_PUB_KEY: u8 = 19;
 430         pub const TAG_DESCRIPTION_HASH: u8 = 23;
 431         pub const TAG_EXPIRY_TIME: u8 = 6;
 432         pub const TAG_MIN_FINAL_CLTV_EXPIRY: u8 = 24;
 433         pub const TAG_FALLBACK: u8 = 9;
 434         pub const TAG_ROUTE: u8 = 3;
 435         pub const TAG_PAYMENT_SECRET: u8 = 16;
 436         pub const TAG_FEATURES: u8 = 5;
 437 }
 438
 439 impl InvoiceBuilder<tb::False, tb::False, tb::False, tb::False, tb::False> {
 440         /// Construct new, empty `InvoiceBuilder`. All necessary fields have to be filled first before
 441         /// `InvoiceBuilder::build(self)` becomes available.
 442         pub fn new(currrency: Currency) -> Self {
 443                 InvoiceBuilder {
 444                         currency: currrency,
 445                         amount: None,
 446                         si_prefix: None,
 447                         timestamp: None,
 448                         tagged_fields: Vec::new(),
 449                         error: None,
 450
 451                         phantom_d: std::marker::PhantomData,
 452                         phantom_h: std::marker::PhantomData,
 453                         phantom_t: std::marker::PhantomData,
 454                         phantom_c: std::marker::PhantomData,
 455                         phantom_s: std::marker::PhantomData,
 456                 }
 457         }
 458 }
 459
 460 impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, T, C, S> {
 461         /// Helper function to set the completeness flags.
 462         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> {
 463                 InvoiceBuilder::<DN, HN, TN, CN, SN> {
 464                         currency: self.currency,
 465                         amount: self.amount,
 466                         si_prefix: self.si_prefix,
 467                         timestamp: self.timestamp,
 468                         tagged_fields: self.tagged_fields,
 469                         error: self.error,
 470
 471                         phantom_d: std::marker::PhantomData,
 472                         phantom_h: std::marker::PhantomData,
 473                         phantom_t: std::marker::PhantomData,
 474                         phantom_c: std::marker::PhantomData,
 475                         phantom_s: std::marker::PhantomData,
 476                 }
 477         }
 478
 479         /// Sets the amount in pico BTC. The optimal SI prefix is choosen automatically.
 480         pub fn amount_pico_btc(mut self, amount: u64) -> Self {
 481                 let biggest_possible_si_prefix = SiPrefix::values_desc()
 482                         .iter()
 483                         .find(|prefix| amount % prefix.multiplier() == 0)
 484                         .expect("Pico should always match");
 485                 self.amount = Some(amount / biggest_possible_si_prefix.multiplier());
 486                 self.si_prefix = Some(*biggest_possible_si_prefix);
 487                 self
 488         }
 489
 490         /// Sets the payee's public key.
 491         pub fn payee_pub_key(mut self, pub_key: PublicKey) -> Self {
 492                 self.tagged_fields.push(TaggedField::PayeePubKey(PayeePubKey(pub_key)));
 493                 self
 494         }
 495
 496         /// Sets the expiry time
 497         pub fn expiry_time(mut self, expiry_time: Duration) -> Self {
 498         match ExpiryTime::from_duration(expiry_time) {
 499             Ok(t) => self.tagged_fields.push(TaggedField::ExpiryTime(t)),
 500             Err(e) => self.error = Some(e),
 501         };
 502                 self
 503         }
 504
 505         /// Adds a fallback address.
 506         pub fn fallback(mut self, fallback: Fallback) -> Self {
 507                 self.tagged_fields.push(TaggedField::Fallback(fallback));
 508                 self
 509         }
 510
 511         /// Adds a private route.
 512         pub fn route(mut self, route: Vec<RouteHintHop>) -> Self {
 513                 match RouteHint::new(route) {
 514                         Ok(r) => self.tagged_fields.push(TaggedField::Route(r)),
 515                         Err(e) => self.error = Some(e),
 516                 }
 517                 self
 518         }
 519 }
 520
 521 impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, tb::True, C, S> {
 522         /// Builds a `RawInvoice` if no `CreationError` occurred while construction any of the fields.
 523         pub fn build_raw(self) -> Result<RawInvoice, CreationError> {
 524
 525                 // If an error occurred at any time before, return it now
 526                 if let Some(e) = self.error {
 527                         return Err(e);
 528                 }
 529
 530                 let hrp = RawHrp {
 531                         currency: self.currency,
 532                         raw_amount: self.amount,
 533                         si_prefix: self.si_prefix,
 534                 };
 535
 536                 let timestamp = self.timestamp.expect("ensured to be Some(t) by type T");
 537
 538                 let tagged_fields = self.tagged_fields.into_iter().map(|tf| {
 539                         RawTaggedField::KnownSemantics(tf)
 540                 }).collect::<Vec<_>>();
 541
 542                 let data = RawDataPart {
 543                         timestamp: timestamp,
 544                         tagged_fields: tagged_fields,
 545                 };
 546
 547                 Ok(RawInvoice {
 548                         hrp: hrp,
 549                         data: data,
 550                 })
 551         }
 552 }
 553
 554 impl<H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<tb::False, H, T, C, S> {
 555         /// Set the description. This function is only available if no description (hash) was set.
 556         pub fn description(mut self, description: String) -> InvoiceBuilder<tb::True, H, T, C, S> {
 557                 match Description::new(description) {
 558                         Ok(d) => self.tagged_fields.push(TaggedField::Description(d)),
 559                         Err(e) => self.error = Some(e),
 560                 }
 561                 self.set_flags()
 562         }
 563
 564         /// Set the description hash. This function is only available if no description (hash) was set.
 565         pub fn description_hash(mut self, description_hash: sha256::Hash) -> InvoiceBuilder<tb::True, H, T, C, S> {
 566                 self.tagged_fields.push(TaggedField::DescriptionHash(Sha256(description_hash)));
 567                 self.set_flags()
 568         }
 569 }
 570
 571 impl<D: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, tb::False, T, C, S> {
 572         /// Set the payment hash. This function is only available if no payment hash was set.
 573         pub fn payment_hash(mut self, hash: sha256::Hash) -> InvoiceBuilder<D, tb::True, T, C, S> {
 574                 self.tagged_fields.push(TaggedField::PaymentHash(Sha256(hash)));
 575                 self.set_flags()
 576         }
 577 }
 578
 579 impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, tb::False, C, S> {
 580         /// Sets the timestamp.
 581         pub fn timestamp(mut self, time: SystemTime) -> InvoiceBuilder<D, H, tb::True, C, S> {
 582                 match PositiveTimestamp::from_system_time(time) {
 583                         Ok(t) => self.timestamp = Some(t),
 584                         Err(e) => self.error = Some(e),
 585                 }
 586
 587                 self.set_flags()
 588         }
 589
 590         /// Sets the timestamp to the current UNIX timestamp.
 591         pub fn current_timestamp(mut self) -> InvoiceBuilder<D, H, tb::True, C, S> {
 592                 let now = PositiveTimestamp::from_system_time(SystemTime::now());
 593                 self.timestamp = Some(now.expect("for the foreseeable future this shouldn't happen"));
 594                 self.set_flags()
 595         }
 596 }
 597
 598 impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, T, tb::False, S> {
 599         /// Sets `min_final_cltv_expiry`.
 600         pub fn min_final_cltv_expiry(mut self, min_final_cltv_expiry: u64) -> InvoiceBuilder<D, H, T, tb::True, S> {
 601                 self.tagged_fields.push(TaggedField::MinFinalCltvExpiry(MinFinalCltvExpiry(min_final_cltv_expiry)));
 602                 self.set_flags()
 603         }
 604 }
 605
 606 impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, T, C, tb::False> {
 607         /// Sets the payment secret and relevant features.
 608         pub fn payment_secret(mut self, payment_secret: PaymentSecret) -> InvoiceBuilder<D, H, T, C, tb::True> {
 609                 let features = InvoiceFeatures::empty()
 610                         .set_variable_length_onion_required()
 611                         .set_payment_secret_required();
 612                 self.tagged_fields.push(TaggedField::PaymentSecret(payment_secret));
 613                 self.tagged_fields.push(TaggedField::Features(features));
 614                 self.set_flags()
 615         }
 616 }
 617
 618 impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, T, C, tb::True> {
 619         /// Sets the `basic_mpp` feature as optional.
 620         pub fn basic_mpp(mut self) -> Self {
 621                 self.tagged_fields = self.tagged_fields
 622                         .drain(..)
 623                         .map(|field| match field {
 624                                 TaggedField::Features(f) => TaggedField::Features(f.set_basic_mpp_optional()),
 625                                 _ => field,
 626                         })
 627                         .collect();
 628                 self
 629         }
 630 }
 631
 632 impl<S: tb::Bool> InvoiceBuilder<tb::True, tb::True, tb::True, tb::True, S> {
 633         /// Builds and signs an invoice using the supplied `sign_function`. This function MAY NOT fail
 634         /// and MUST produce a recoverable signature valid for the given hash and if applicable also for
 635         /// the included payee public key.
 636         pub fn build_signed<F>(self, sign_function: F) -> Result<Invoice, CreationError>
 637                 where F: FnOnce(&Message) -> RecoverableSignature
 638         {
 639                 let invoice = self.try_build_signed::<_, ()>(|hash| {
 640                         Ok(sign_function(hash))
 641                 });
 642
 643                 match invoice {
 644                         Ok(i) => Ok(i),
 645                         Err(SignOrCreationError::CreationError(e)) => Err(e),
 646                         Err(SignOrCreationError::SignError(())) => unreachable!(),
 647                 }
 648         }
 649
 650         /// Builds and signs an invoice using the supplied `sign_function`. This function MAY fail with
 651         /// an error of type `E` and MUST produce a recoverable signature valid for the given hash and
 652         /// if applicable also for the included payee public key.
 653         pub fn try_build_signed<F, E>(self, sign_function: F) -> Result<Invoice, SignOrCreationError<E>>
 654                 where F: FnOnce(&Message) -> Result<RecoverableSignature, E>
 655         {
 656                 let raw = match self.build_raw() {
 657                         Ok(r) => r,
 658                         Err(e) => return Err(SignOrCreationError::CreationError(e)),
 659                 };
 660
 661                 let signed = match raw.sign(sign_function) {
 662                         Ok(s) => s,
 663                         Err(e) => return Err(SignOrCreationError::SignError(e)),
 664                 };
 665
 666                 let invoice = Invoice {
 667                         signed_invoice: signed,
 668                 };
 669
 670                 invoice.check_field_counts().expect("should be ensured by type signature of builder");
 671                 invoice.check_feature_bits().expect("should be ensured by type signature of builder");
 672
 673                 Ok(invoice)
 674         }
 675 }
 676
 677
 678 impl SignedRawInvoice {
 679         /// Disassembles the `SignedRawInvoice` into its three parts:
 680         ///  1. raw invoice
 681         ///  2. hash of the raw invoice
 682         ///  3. signature
 683         pub fn into_parts(self) -> (RawInvoice, [u8; 32], InvoiceSignature) {
 684                 (self.raw_invoice, self.hash, self.signature)
 685         }
 686
 687         /// The `RawInvoice` which was signed.
 688         pub fn raw_invoice(&self) -> &RawInvoice {
 689                 &self.raw_invoice
 690         }
 691
 692         /// The hash of the `RawInvoice` that was signed.
 693         pub fn hash(&self) -> &[u8; 32] {
 694                 &self.hash
 695         }
 696
 697         /// InvoiceSignature for the invoice.
 698         pub fn signature(&self) -> &InvoiceSignature {
 699                 &self.signature
 700         }
 701
 702         /// Recovers the public key used for signing the invoice from the recoverable signature.
 703         pub fn recover_payee_pub_key(&self) -> Result<PayeePubKey, secp256k1::Error> {
 704                 let hash = Message::from_slice(&self.hash[..])
 705                         .expect("Hash is 32 bytes long, same as MESSAGE_SIZE");
 706
 707                 Ok(PayeePubKey(Secp256k1::new().recover(
 708                         &hash,
 709                         &self.signature
 710                 )?))
 711         }
 712
 713         /// Checks if the signature is valid for the included payee public key or if none exists if it's
 714         /// valid for the recovered signature (which should always be true?).
 715         pub fn check_signature(&self) -> bool {
 716                 let included_pub_key = self.raw_invoice.payee_pub_key();
 717
 718                 let mut recovered_pub_key = Option::None;
 719                 if recovered_pub_key.is_none() {
 720                         let recovered = match self.recover_payee_pub_key() {
 721                                 Ok(pk) => pk,
 722                                 Err(_) => return false,
 723                         };
 724                         recovered_pub_key = Some(recovered);
 725                 }
 726
 727                 let pub_key = included_pub_key.or_else(|| recovered_pub_key.as_ref())
 728                         .expect("One is always present");
 729
 730                 let hash = Message::from_slice(&self.hash[..])
 731                         .expect("Hash is 32 bytes long, same as MESSAGE_SIZE");
 732
 733                 let secp_context = Secp256k1::new();
 734                 let verification_result = secp_context.verify(
 735                         &hash,
 736                         &self.signature.to_standard(),
 737                         pub_key
 738                 );
 739
 740                 match verification_result {
 741                         Ok(()) => true,
 742                         Err(_) => false,
 743                 }
 744         }
 745 }
 746
 747 /// Finds the first element of an enum stream of a given variant and extracts one member of the
 748 /// variant. If no element was found `None` gets returned.
 749 ///
 750 /// The following example would extract the first B.
 751 /// ```
 752 /// use Enum::*
 753 ///
 754 /// enum Enum {
 755 ///     A(u8),
 756 ///     B(u16)
 757 /// }
 758 ///
 759 /// let elements = vec![A(1), A(2), B(3), A(4)]
 760 ///
 761 /// assert_eq!(find_extract!(elements.iter(), Enum::B(ref x), x), Some(3u16))
 762 /// ```
 763 macro_rules! find_extract {
 764         ($iter:expr, $enm:pat, $enm_var:ident) => {
 765                 find_all_extract!($iter, $enm, $enm_var).next()
 766     };
 767 }
 768
 769 /// Finds the all elements of an enum stream of a given variant and extracts one member of the
 770 /// variant through an iterator.
 771 ///
 772 /// The following example would extract all A.
 773 /// ```
 774 /// use Enum::*
 775 ///
 776 /// enum Enum {
 777 ///     A(u8),
 778 ///     B(u16)
 779 /// }
 780 ///
 781 /// let elements = vec![A(1), A(2), B(3), A(4)]
 782 ///
 783 /// assert_eq!(
 784 ///     find_all_extract!(elements.iter(), Enum::A(ref x), x).collect::<Vec<u8>>(),
 785 ///     vec![1u8, 2u8, 4u8])
 786 /// ```
 787 macro_rules! find_all_extract {
 788         ($iter:expr, $enm:pat, $enm_var:ident) => {
 789         $iter.filter_map(|tf| match *tf {
 790                         $enm => Some($enm_var),
 791                         _ => None,
 792                 })
 793     };
 794 }
 795
 796 #[allow(missing_docs)]
 797 impl RawInvoice {
 798         /// Construct the invoice's HRP and signatureless data into a preimage to be hashed.
 799         pub(crate) fn construct_invoice_preimage(hrp_bytes: &[u8], data_without_signature: &[u5]) -> Vec<u8> {
 800                 use bech32::FromBase32;
 801
 802                 let mut preimage = Vec::<u8>::from(hrp_bytes);
 803
 804                 let mut data_part = Vec::from(data_without_signature);
 805                 let overhang = (data_part.len() * 5) % 8;
 806                 if overhang > 0 {
 807                         // add padding if data does not end at a byte boundary
 808                         data_part.push(u5::try_from_u8(0).unwrap());
 809
 810                         // if overhang is in (1..3) we need to add u5(0) padding two times
 811                         if overhang < 3 {
 812                                 data_part.push(u5::try_from_u8(0).unwrap());
 813                         }
 814                 }
 815
 816                 preimage.extend_from_slice(&Vec::<u8>::from_base32(&data_part)
 817                         .expect("No padding error may occur due to appended zero above."));
 818                 preimage
 819         }
 820
 821         /// Hash the HRP as bytes and signatureless data part.
 822         fn hash_from_parts(hrp_bytes: &[u8], data_without_signature: &[u5]) -> [u8; 32] {
 823                 let preimage = RawInvoice::construct_invoice_preimage(hrp_bytes, data_without_signature);
 824                 let mut hash: [u8; 32] = Default::default();
 825                 hash.copy_from_slice(&sha256::Hash::hash(&preimage)[..]);
 826                 hash
 827         }
 828
 829         /// Calculate the hash of the encoded `RawInvoice`
 830         pub fn hash(&self) -> [u8; 32] {
 831                 use bech32::ToBase32;
 832
 833                 RawInvoice::hash_from_parts(
 834                         self.hrp.to_string().as_bytes(),
 835                         &self.data.to_base32()
 836                 )
 837         }
 838
 839         /// Signs the invoice using the supplied `sign_function`. This function MAY fail with an error
 840         /// of type `E`. Since the signature of a `SignedRawInvoice` is not required to be valid there
 841         /// are no constraints regarding the validity of the produced signature.
 842         ///
 843         /// (C-not exported) As we don't currently support passing function pointers into methods
 844         /// explicitly.
 845         pub fn sign<F, E>(self, sign_method: F) -> Result<SignedRawInvoice, E>
 846                 where F: FnOnce(&Message) -> Result<RecoverableSignature, E>
 847         {
 848                 let raw_hash = self.hash();
 849                 let hash = Message::from_slice(&raw_hash[..])
 850                         .expect("Hash is 32 bytes long, same as MESSAGE_SIZE");
 851                 let signature = sign_method(&hash)?;
 852
 853                 Ok(SignedRawInvoice {
 854                         raw_invoice: self,
 855                         hash: raw_hash,
 856                         signature: InvoiceSignature(signature),
 857                 })
 858         }
 859
 860         /// Returns an iterator over all tagged fields with known semantics.
 861         ///
 862         /// (C-not exported) As there is not yet a manual mapping for a FilterMap
 863         pub fn known_tagged_fields(&self)
 864                 -> FilterMap<Iter<RawTaggedField>, fn(&RawTaggedField) -> Option<&TaggedField>>
 865         {
 866                 // For 1.14.0 compatibility: closures' types can't be written an fn()->() in the
 867                 // function's type signature.
 868                 // TODO: refactor once impl Trait is available
 869                 fn match_raw(raw: &RawTaggedField) -> Option<&TaggedField> {
 870                         match *raw {
 871                                 RawTaggedField::KnownSemantics(ref tf) => Some(tf),
 872                                 _ => None,
 873                         }
 874                 }
 875
 876                 self.data.tagged_fields.iter().filter_map(match_raw )
 877         }
 878
 879         pub fn payment_hash(&self) -> Option<&Sha256> {
 880                 find_extract!(self.known_tagged_fields(), TaggedField::PaymentHash(ref x), x)
 881         }
 882
 883         pub fn description(&self) -> Option<&Description> {
 884                 find_extract!(self.known_tagged_fields(), TaggedField::Description(ref x), x)
 885         }
 886
 887         pub fn payee_pub_key(&self) -> Option<&PayeePubKey> {
 888                 find_extract!(self.known_tagged_fields(), TaggedField::PayeePubKey(ref x), x)
 889         }
 890
 891         pub fn description_hash(&self) -> Option<&Sha256> {
 892                 find_extract!(self.known_tagged_fields(), TaggedField::DescriptionHash(ref x), x)
 893         }
 894
 895         pub fn expiry_time(&self) -> Option<&ExpiryTime> {
 896                 find_extract!(self.known_tagged_fields(), TaggedField::ExpiryTime(ref x), x)
 897         }
 898
 899         pub fn min_final_cltv_expiry(&self) -> Option<&MinFinalCltvExpiry> {
 900                 find_extract!(self.known_tagged_fields(), TaggedField::MinFinalCltvExpiry(ref x), x)
 901         }
 902
 903         pub fn payment_secret(&self) -> Option<&PaymentSecret> {
 904                 find_extract!(self.known_tagged_fields(), TaggedField::PaymentSecret(ref x), x)
 905         }
 906
 907         pub fn features(&self) -> Option<&InvoiceFeatures> {
 908                 find_extract!(self.known_tagged_fields(), TaggedField::Features(ref x), x)
 909         }
 910
 911         /// (C-not exported) as we don't support Vec<&NonOpaqueType>
 912         pub fn fallbacks(&self) -> Vec<&Fallback> {
 913                 find_all_extract!(self.known_tagged_fields(), TaggedField::Fallback(ref x), x).collect()
 914         }
 915
 916         pub fn routes(&self) -> Vec<&RouteHint> {
 917                 find_all_extract!(self.known_tagged_fields(), TaggedField::Route(ref x), x).collect()
 918         }
 919
 920         pub fn amount_pico_btc(&self) -> Option<u64> {
 921                 self.hrp.raw_amount.map(|v| {
 922                         v * self.hrp.si_prefix.as_ref().map_or(1_000_000_000_000, |si| { si.multiplier() })
 923                 })
 924         }
 925
 926         pub fn currency(&self) -> Currency {
 927                 self.hrp.currency.clone()
 928         }
 929 }
 930
 931 impl PositiveTimestamp {
 932         /// Create a new `PositiveTimestamp` from a unix timestamp in the Range
 933         /// `0...SYSTEM_TIME_MAX_UNIX_TIMESTAMP - MAX_EXPIRY_TIME`, otherwise return a
 934         /// `CreationError::TimestampOutOfBounds`.
 935         pub fn from_unix_timestamp(unix_seconds: u64) -> Result<Self, CreationError> {
 936                 if unix_seconds > SYSTEM_TIME_MAX_UNIX_TIMESTAMP - MAX_EXPIRY_TIME {
 937                         Err(CreationError::TimestampOutOfBounds)
 938                 } else {
 939                         Ok(PositiveTimestamp(UNIX_EPOCH + Duration::from_secs(unix_seconds)))
 940                 }
 941         }
 942
 943         /// Create a new `PositiveTimestamp` from a `SystemTime` with a corresponding unix timestamp in
 944         /// the Range `0...SYSTEM_TIME_MAX_UNIX_TIMESTAMP - MAX_EXPIRY_TIME`, otherwise return a
 945         /// `CreationError::TimestampOutOfBounds`.
 946         pub fn from_system_time(time: SystemTime) -> Result<Self, CreationError> {
 947                 if time
 948                         .duration_since(UNIX_EPOCH)
 949                         .map(|t| t.as_secs() <= SYSTEM_TIME_MAX_UNIX_TIMESTAMP - MAX_EXPIRY_TIME)
 950                         .unwrap_or(true)
 951                         {
 952                                 Ok(PositiveTimestamp(time))
 953                         } else {
 954                         Err(CreationError::TimestampOutOfBounds)
 955                 }
 956         }
 957
 958         /// Returns the UNIX timestamp representing the stored time
 959         pub fn as_unix_timestamp(&self) -> u64 {
 960                 self.0.duration_since(UNIX_EPOCH)
 961                         .expect("ensured by type contract/constructors")
 962                         .as_secs()
 963         }
 964
 965         /// Returns a reference to the internal `SystemTime` time representation
 966         pub fn as_time(&self) -> &SystemTime {
 967                 &self.0
 968         }
 969 }
 970
 971 impl Into<SystemTime> for PositiveTimestamp {
 972         fn into(self) -> SystemTime {
 973                 self.0
 974         }
 975 }
 976
 977 impl Deref for PositiveTimestamp {
 978         type Target = SystemTime;
 979
 980         fn deref(&self) -> &Self::Target {
 981                 &self.0
 982         }
 983 }
 984
 985 impl Invoice {
 986         /// Transform the `Invoice` into it's unchecked version
 987         pub fn into_signed_raw(self) -> SignedRawInvoice {
 988                 self.signed_invoice
 989         }
 990
 991         /// Check that all mandatory fields are present
 992         fn check_field_counts(&self) -> Result<(), SemanticError> {
 993                 // "A writer MUST include exactly one p field […]."
 994                 let payment_hash_cnt = self.tagged_fields().filter(|&tf| match *tf {
 995                         TaggedField::PaymentHash(_) => true,
 996                         _ => false,
 997                 }).count();
 998                 if payment_hash_cnt < 1 {
 999                         return Err(SemanticError::NoPaymentHash);
1000                 } else if payment_hash_cnt > 1 {
1001                         return Err(SemanticError::MultiplePaymentHashes);
1002                 }
1003
1004                 // "A writer MUST include either exactly one d or exactly one h field."
1005                 let description_cnt = self.tagged_fields().filter(|&tf| match *tf {
1006                         TaggedField::Description(_) | TaggedField::DescriptionHash(_) => true,
1007                         _ => false,
1008                 }).count();
1009                 if  description_cnt < 1 {
1010                         return Err(SemanticError::NoDescription);
1011                 } else if description_cnt > 1 {
1012                         return  Err(SemanticError::MultipleDescriptions);
1013                 }
1014
1015                 Ok(())
1016         }
1017
1018         /// Check that feature bits are set as required
1019         fn check_feature_bits(&self) -> Result<(), SemanticError> {
1020                 // "If the payment_secret feature is set, MUST include exactly one s field."
1021                 let payment_secret_count = self.tagged_fields().filter(|&tf| match *tf {
1022                         TaggedField::PaymentSecret(_) => true,
1023                         _ => false,
1024                 }).count();
1025                 if payment_secret_count > 1 {
1026                         return Err(SemanticError::MultiplePaymentSecrets);
1027                 }
1028
1029                 // "A writer MUST set an s field if and only if the payment_secret feature is set."
1030                 let has_payment_secret = payment_secret_count == 1;
1031                 let features = self.tagged_fields().find(|&tf| match *tf {
1032                         TaggedField::Features(_) => true,
1033                         _ => false,
1034                 });
1035                 match features {
1036                         None if has_payment_secret => Err(SemanticError::InvalidFeatures),
1037                         None => Ok(()),
1038                         Some(TaggedField::Features(features)) => {
1039                                 if features.supports_payment_secret() && has_payment_secret {
1040                                         Ok(())
1041                                 } else if has_payment_secret {
1042                                         Err(SemanticError::InvalidFeatures)
1043                                 } else if features.supports_payment_secret() {
1044                                         Err(SemanticError::InvalidFeatures)
1045                                 } else {
1046                                         Ok(())
1047                                 }
1048                         },
1049                         Some(_) => unreachable!(),
1050                 }
1051         }
1052
1053         /// Check that the invoice is signed correctly and that key recovery works
1054         pub fn check_signature(&self) -> Result<(), SemanticError> {
1055                 match self.signed_invoice.recover_payee_pub_key() {
1056                         Err(secp256k1::Error::InvalidRecoveryId) =>
1057                                 return Err(SemanticError::InvalidRecoveryId),
1058                         Err(_) => panic!("no other error may occur"),
1059                         Ok(_) => {},
1060                 }
1061
1062                 if !self.signed_invoice.check_signature() {
1063                         return Err(SemanticError::InvalidSignature);
1064                 }
1065
1066                 Ok(())
1067         }
1068
1069         /// Constructs an `Invoice` from a `SignedInvoice` by checking all its invariants.
1070         /// ```
1071         /// use lightning_invoice::*;
1072         ///
1073         /// let invoice = "lnbc1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdp\
1074         ///     l2pkx2ctnv5sxxmmwwd5kgetjypeh2ursdae8g6twvus8g6rfwvs8qun0dfjkxaq8rkx3yf5tcsyz3d7\
1075         ///     3gafnh3cax9rn449d9p5uxz9ezhhypd0elx87sjle52x86fux2ypatgddc6k63n7erqz25le42c4u4ec\
1076         ///     ky03ylcqca784w";
1077         ///
1078         /// let signed = invoice.parse::<SignedRawInvoice>().unwrap();
1079         ///
1080         /// assert!(Invoice::from_signed(signed).is_ok());
1081         /// ```
1082         pub fn from_signed(signed_invoice: SignedRawInvoice) -> Result<Self, SemanticError> {
1083                 let invoice = Invoice {
1084                         signed_invoice: signed_invoice,
1085                 };
1086                 invoice.check_field_counts()?;
1087                 invoice.check_feature_bits()?;
1088                 invoice.check_signature()?;
1089
1090                 Ok(invoice)
1091         }
1092
1093         /// Returns the `Invoice`'s timestamp (should equal it's creation time)
1094         pub fn timestamp(&self) -> &SystemTime {
1095                 self.signed_invoice.raw_invoice().data.timestamp.as_time()
1096         }
1097
1098         /// Returns an iterator over all tagged fields of this Invoice.
1099         ///
1100         /// (C-not exported) As there is not yet a manual mapping for a FilterMap
1101         pub fn tagged_fields(&self)
1102                 -> FilterMap<Iter<RawTaggedField>, fn(&RawTaggedField) -> Option<&TaggedField>> {
1103                 self.signed_invoice.raw_invoice().known_tagged_fields()
1104         }
1105
1106         /// Returns the hash to which we will receive the preimage on completion of the payment
1107         pub fn payment_hash(&self) -> &sha256::Hash {
1108                 &self.signed_invoice.payment_hash().expect("checked by constructor").0
1109         }
1110
1111         /// Return the description or a hash of it for longer ones
1112         ///
1113         /// (C-not exported) because we don't yet export InvoiceDescription
1114         pub fn description(&self) -> InvoiceDescription {
1115                 if let Some(ref direct) = self.signed_invoice.description() {
1116                         return InvoiceDescription::Direct(direct);
1117                 } else if let Some(ref hash) = self.signed_invoice.description_hash() {
1118                         return InvoiceDescription::Hash(hash);
1119                 }
1120                 unreachable!("ensured by constructor");
1121         }
1122
1123         /// Get the payee's public key if one was included in the invoice
1124         pub fn payee_pub_key(&self) -> Option<&PublicKey> {
1125                 self.signed_invoice.payee_pub_key().map(|x| &x.0)
1126         }
1127
1128         /// Get the payment secret if one was included in the invoice
1129         pub fn payment_secret(&self) -> Option<&PaymentSecret> {
1130                 self.signed_invoice.payment_secret()
1131         }
1132
1133         /// Get the invoice features if they were included in the invoice
1134         pub fn features(&self) -> Option<&InvoiceFeatures> {
1135                 self.signed_invoice.features()
1136         }
1137
1138         /// Recover the payee's public key (only to be used if none was included in the invoice)
1139         pub fn recover_payee_pub_key(&self) -> PublicKey {
1140                 self.signed_invoice.recover_payee_pub_key().expect("was checked by constructor").0
1141         }
1142
1143         /// Returns the invoice's expiry time, if present, otherwise [`DEFAULT_EXPIRY_TIME`].
1144         pub fn expiry_time(&self) -> Duration {
1145                 self.signed_invoice.expiry_time()
1146                         .map(|x| x.0)
1147                         .unwrap_or(Duration::from_secs(DEFAULT_EXPIRY_TIME))
1148         }
1149
1150         /// Returns the invoice's `min_final_cltv_expiry` time, if present, otherwise
1151         /// [`DEFAULT_MIN_FINAL_CLTV_EXPIRY`].
1152         pub fn min_final_cltv_expiry(&self) -> u64 {
1153                 self.signed_invoice.min_final_cltv_expiry()
1154                         .map(|x| x.0)
1155                         .unwrap_or(DEFAULT_MIN_FINAL_CLTV_EXPIRY)
1156         }
1157
1158         /// Returns a list of all fallback addresses
1159         ///
1160         /// (C-not exported) as we don't support Vec<&NonOpaqueType>
1161         pub fn fallbacks(&self) -> Vec<&Fallback> {
1162                 self.signed_invoice.fallbacks()
1163         }
1164
1165         /// Returns a list of all routes included in the invoice
1166         pub fn routes(&self) -> Vec<&RouteHint> {
1167                 self.signed_invoice.routes()
1168         }
1169
1170         /// Returns the currency for which the invoice was issued
1171         pub fn currency(&self) -> Currency {
1172                 self.signed_invoice.currency()
1173         }
1174
1175         /// Returns the amount if specified in the invoice as pico <currency>.
1176         pub fn amount_pico_btc(&self) -> Option<u64> {
1177                 self.signed_invoice.amount_pico_btc()
1178         }
1179 }
1180
1181 impl From<TaggedField> for RawTaggedField {
1182         fn from(tf: TaggedField) -> Self {
1183                 RawTaggedField::KnownSemantics(tf)
1184         }
1185 }
1186
1187 impl TaggedField {
1188         /// Numeric representation of the field's tag
1189         pub fn tag(&self) -> u5 {
1190                 let tag = match *self {
1191                         TaggedField::PaymentHash(_) => constants::TAG_PAYMENT_HASH,
1192                         TaggedField::Description(_) => constants::TAG_DESCRIPTION,
1193                         TaggedField::PayeePubKey(_) => constants::TAG_PAYEE_PUB_KEY,
1194                         TaggedField::DescriptionHash(_) => constants::TAG_DESCRIPTION_HASH,
1195                         TaggedField::ExpiryTime(_) => constants::TAG_EXPIRY_TIME,
1196                         TaggedField::MinFinalCltvExpiry(_) => constants::TAG_MIN_FINAL_CLTV_EXPIRY,
1197                         TaggedField::Fallback(_) => constants::TAG_FALLBACK,
1198                         TaggedField::Route(_) => constants::TAG_ROUTE,
1199                         TaggedField::PaymentSecret(_) => constants::TAG_PAYMENT_SECRET,
1200                         TaggedField::Features(_) => constants::TAG_FEATURES,
1201                 };
1202
1203                 u5::try_from_u8(tag).expect("all tags defined are <32")
1204         }
1205 }
1206
1207 impl Description {
1208
1209         /// Creates a new `Description` if `description` is at most 1023 __bytes__ long,
1210         /// returns `CreationError::DescriptionTooLong` otherwise
1211         ///
1212         /// Please note that single characters may use more than one byte due to UTF8 encoding.
1213         pub fn new(description: String) -> Result<Description, CreationError> {
1214                 if description.len() > 639 {
1215                         Err(CreationError::DescriptionTooLong)
1216                 } else {
1217                         Ok(Description(description))
1218                 }
1219         }
1220
1221         /// Returns the underlying description `String`
1222         pub fn into_inner(self) -> String {
1223                 self.0
1224         }
1225 }
1226
1227 impl Into<String> for Description {
1228         fn into(self) -> String {
1229                 self.into_inner()
1230         }
1231 }
1232
1233 impl Deref for Description {
1234         type Target = str;
1235
1236         fn deref(&self) -> &str {
1237                 &self.0
1238         }
1239 }
1240
1241 impl From<PublicKey> for PayeePubKey {
1242         fn from(pk: PublicKey) -> Self {
1243                 PayeePubKey(pk)
1244         }
1245 }
1246
1247 impl Deref for PayeePubKey {
1248         type Target = PublicKey;
1249
1250         fn deref(&self) -> &PublicKey {
1251                 &self.0
1252         }
1253 }
1254
1255 impl ExpiryTime {
1256         /// Construct an `ExpiryTime` from seconds. If there exists a `PositiveTimestamp` which would
1257         /// overflow on adding the `EpiryTime` to it then this function will return a
1258         /// `CreationError::ExpiryTimeOutOfBounds`.
1259         pub fn from_seconds(seconds: u64) -> Result<ExpiryTime, CreationError> {
1260                 if seconds <= MAX_EXPIRY_TIME {
1261                         Ok(ExpiryTime(Duration::from_secs(seconds)))
1262                 } else {
1263                         Err(CreationError::ExpiryTimeOutOfBounds)
1264                 }
1265         }
1266
1267         /// Construct an `ExpiryTime` from a `Duration`. If there exists a `PositiveTimestamp` which
1268         /// would overflow on adding the `EpiryTime` to it then this function will return a
1269         /// `CreationError::ExpiryTimeOutOfBounds`.
1270         pub fn from_duration(duration: Duration) -> Result<ExpiryTime, CreationError> {
1271                 if duration.as_secs() <= MAX_EXPIRY_TIME {
1272                         Ok(ExpiryTime(duration))
1273                 } else {
1274                         Err(CreationError::ExpiryTimeOutOfBounds)
1275                 }
1276         }
1277
1278         /// Returns the expiry time in seconds
1279         pub fn as_seconds(&self) -> u64 {
1280                 self.0.as_secs()
1281         }
1282
1283         /// Returns a reference to the underlying `Duration` (=expiry time)
1284         pub fn as_duration(&self) -> &Duration {
1285                 &self.0
1286         }
1287 }
1288
1289 impl RouteHint {
1290         /// Create a new (partial) route from a list of hops
1291         pub fn new(hops: Vec<RouteHintHop>) -> Result<RouteHint, CreationError> {
1292                 if hops.len() <= 12 {
1293                         Ok(RouteHint(hops))
1294                 } else {
1295                         Err(CreationError::RouteTooLong)
1296                 }
1297         }
1298
1299         /// Returrn the underlying vector of hops
1300         pub fn into_inner(self) -> Vec<RouteHintHop> {
1301                 self.0
1302         }
1303 }
1304
1305 impl Into<Vec<RouteHintHop>> for RouteHint {
1306         fn into(self) -> Vec<RouteHintHop> {
1307                 self.into_inner()
1308         }
1309 }
1310
1311 impl Deref for RouteHint {
1312         type Target = Vec<RouteHintHop>;
1313
1314         fn deref(&self) -> &Vec<RouteHintHop> {
1315                 &self.0
1316         }
1317 }
1318
1319 impl Deref for InvoiceSignature {
1320         type Target = RecoverableSignature;
1321
1322         fn deref(&self) -> &RecoverableSignature {
1323                 &self.0
1324         }
1325 }
1326
1327 impl Deref for SignedRawInvoice {
1328         type Target = RawInvoice;
1329
1330         fn deref(&self) -> &RawInvoice {
1331                 &self.raw_invoice
1332         }
1333 }
1334
1335 /// Errors that may occur when constructing a new `RawInvoice` or `Invoice`
1336 #[derive(Eq, PartialEq, Debug, Clone)]
1337 pub enum CreationError {
1338         /// The supplied description string was longer than 639 __bytes__ (see [`Description::new(…)`](./struct.Description.html#method.new))
1339         DescriptionTooLong,
1340
1341         /// The specified route has too many hops and can't be encoded
1342         RouteTooLong,
1343
1344         /// The unix timestamp of the supplied date is <0 or can't be represented as `SystemTime`
1345         TimestampOutOfBounds,
1346
1347         /// The supplied expiry time could cause an overflow if added to a `PositiveTimestamp`
1348         ExpiryTimeOutOfBounds,
1349 }
1350
1351 impl Display for CreationError {
1352         fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
1353                 match self {
1354                         CreationError::DescriptionTooLong => f.write_str("The supplied description string was longer than 639 bytes"),
1355                         CreationError::RouteTooLong => f.write_str("The specified route has too many hops and can't be encoded"),
1356                         CreationError::TimestampOutOfBounds => f.write_str("The unix timestamp of the supplied date is <0 or can't be represented as `SystemTime`"),
1357                         CreationError::ExpiryTimeOutOfBounds => f.write_str("The supplied expiry time could cause an overflow if added to a `PositiveTimestamp`"),
1358                 }
1359         }
1360 }
1361
1362 impl std::error::Error for CreationError { }
1363
1364 /// Errors that may occur when converting a `RawInvoice` to an `Invoice`. They relate to the
1365 /// requirements sections in BOLT #11
1366 #[derive(Eq, PartialEq, Debug, Clone)]
1367 pub enum SemanticError {
1368         /// The invoice is missing the mandatory payment hash
1369         NoPaymentHash,
1370
1371         /// The invoice has multiple payment hashes which isn't allowed
1372         MultiplePaymentHashes,
1373
1374         /// No description or description hash are part of the invoice
1375         NoDescription,
1376
1377         /// The invoice contains multiple descriptions and/or description hashes which isn't allowed
1378         MultipleDescriptions,
1379
1380         /// The invoice contains multiple payment secrets
1381         MultiplePaymentSecrets,
1382
1383         /// The invoice's features are invalid
1384         InvalidFeatures,
1385
1386         /// The recovery id doesn't fit the signature/pub key
1387         InvalidRecoveryId,
1388
1389         /// The invoice's signature is invalid
1390         InvalidSignature,
1391 }
1392
1393 impl Display for SemanticError {
1394         fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
1395                 match self {
1396                         SemanticError::NoPaymentHash => f.write_str("The invoice is missing the mandatory payment hash"),
1397                         SemanticError::MultiplePaymentHashes => f.write_str("The invoice has multiple payment hashes which isn't allowed"),
1398                         SemanticError::NoDescription => f.write_str("No description or description hash are part of the invoice"),
1399                         SemanticError::MultipleDescriptions => f.write_str("The invoice contains multiple descriptions and/or description hashes which isn't allowed"),
1400                         SemanticError::MultiplePaymentSecrets => f.write_str("The invoice contains multiple payment secrets"),
1401                         SemanticError::InvalidFeatures => f.write_str("The invoice's features are invalid"),
1402                         SemanticError::InvalidRecoveryId => f.write_str("The recovery id doesn't fit the signature/pub key"),
1403                         SemanticError::InvalidSignature => f.write_str("The invoice's signature is invalid"),
1404                 }
1405         }
1406 }
1407
1408 impl std::error::Error for SemanticError { }
1409
1410 /// When signing using a fallible method either an user-supplied `SignError` or a `CreationError`
1411 /// may occur.
1412 #[derive(Eq, PartialEq, Debug, Clone)]
1413 pub enum SignOrCreationError<S = ()> {
1414         /// An error occurred during signing
1415         SignError(S),
1416
1417         /// An error occurred while building the transaction
1418         CreationError(CreationError),
1419 }
1420
1421 impl<S> Display for SignOrCreationError<S> {
1422         fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
1423                 match self {
1424                         SignOrCreationError::SignError(_) => f.write_str("An error occurred during signing"),
1425                         SignOrCreationError::CreationError(err) => err.fmt(f),
1426                 }
1427         }
1428 }
1429
1430 #[cfg(test)]
1431 mod test {
1432         use bitcoin_hashes::hex::FromHex;
1433         use bitcoin_hashes::sha256;
1434
1435         #[test]
1436         fn test_system_time_bounds_assumptions() {
1437                 ::check_platform();
1438
1439         assert_eq!(
1440             ::PositiveTimestamp::from_unix_timestamp(::SYSTEM_TIME_MAX_UNIX_TIMESTAMP + 1),
1441             Err(::CreationError::TimestampOutOfBounds)
1442         );
1443
1444         assert_eq!(
1445             ::ExpiryTime::from_seconds(::MAX_EXPIRY_TIME + 1),
1446             Err(::CreationError::ExpiryTimeOutOfBounds)
1447         );
1448         }
1449
1450         #[test]
1451         fn test_calc_invoice_hash() {
1452                 use ::{RawInvoice, RawHrp, RawDataPart, Currency, PositiveTimestamp};
1453                 use ::TaggedField::*;
1454
1455                 let invoice = RawInvoice {
1456                         hrp: RawHrp {
1457                                 currency: Currency::Bitcoin,
1458                                 raw_amount: None,
1459                                 si_prefix: None,
1460                         },
1461                         data: RawDataPart {
1462                                 timestamp: PositiveTimestamp::from_unix_timestamp(1496314658).unwrap(),
1463                                 tagged_fields: vec![
1464                                         PaymentHash(::Sha256(sha256::Hash::from_hex(
1465                                                 "0001020304050607080900010203040506070809000102030405060708090102"
1466                                         ).unwrap())).into(),
1467                                         Description(::Description::new(
1468                                                 "Please consider supporting this project".to_owned()
1469                                         ).unwrap()).into(),
1470                                 ],
1471                         },
1472                 };
1473
1474                 let expected_hash = [
1475                         0xc3, 0xd4, 0xe8, 0x3f, 0x64, 0x6f, 0xa7, 0x9a, 0x39, 0x3d, 0x75, 0x27, 0x7b, 0x1d,
1476                         0x85, 0x8d, 0xb1, 0xd1, 0xf7, 0xab, 0x71, 0x37, 0xdc, 0xb7, 0x83, 0x5d, 0xb2, 0xec,
1477                         0xd5, 0x18, 0xe1, 0xc9
1478                 ];
1479
1480                 assert_eq!(invoice.hash(), expected_hash)
1481         }
1482
1483         #[test]
1484         fn test_check_signature() {
1485                 use TaggedField::*;
1486                 use secp256k1::Secp256k1;
1487                 use secp256k1::recovery::{RecoveryId, RecoverableSignature};
1488                 use secp256k1::key::{SecretKey, PublicKey};
1489                 use {SignedRawInvoice, InvoiceSignature, RawInvoice, RawHrp, RawDataPart, Currency, Sha256,
1490                          PositiveTimestamp};
1491
1492                 let invoice = SignedRawInvoice {
1493                         raw_invoice: RawInvoice {
1494                                 hrp: RawHrp {
1495                                         currency: Currency::Bitcoin,
1496                                         raw_amount: None,
1497                                         si_prefix: None,
1498                                 },
1499                                 data: RawDataPart {
1500                                         timestamp: PositiveTimestamp::from_unix_timestamp(1496314658).unwrap(),
1501                                         tagged_fields: vec ! [
1502                                                 PaymentHash(Sha256(sha256::Hash::from_hex(
1503                                                         "0001020304050607080900010203040506070809000102030405060708090102"
1504                                                 ).unwrap())).into(),
1505                                                 Description(
1506                                                         ::Description::new(
1507                                                                 "Please consider supporting this project".to_owned()
1508                                                         ).unwrap()
1509                                                 ).into(),
1510                                         ],
1511                                 },
1512                         },
1513                         hash: [
1514                                 0xc3, 0xd4, 0xe8, 0x3f, 0x64, 0x6f, 0xa7, 0x9a, 0x39, 0x3d, 0x75, 0x27,
1515                                 0x7b, 0x1d, 0x85, 0x8d, 0xb1, 0xd1, 0xf7, 0xab, 0x71, 0x37, 0xdc, 0xb7,
1516                                 0x83, 0x5d, 0xb2, 0xec, 0xd5, 0x18, 0xe1, 0xc9
1517                         ],
1518                         signature: InvoiceSignature(RecoverableSignature::from_compact(
1519                                 & [
1520                                         0x38u8, 0xec, 0x68, 0x91, 0x34, 0x5e, 0x20, 0x41, 0x45, 0xbe, 0x8a,
1521                                         0x3a, 0x99, 0xde, 0x38, 0xe9, 0x8a, 0x39, 0xd6, 0xa5, 0x69, 0x43,
1522                                         0x4e, 0x18, 0x45, 0xc8, 0xaf, 0x72, 0x05, 0xaf, 0xcf, 0xcc, 0x7f,
1523                                         0x42, 0x5f, 0xcd, 0x14, 0x63, 0xe9, 0x3c, 0x32, 0x88, 0x1e, 0xad,
1524                                         0x0d, 0x6e, 0x35, 0x6d, 0x46, 0x7e, 0xc8, 0xc0, 0x25, 0x53, 0xf9,
1525                                         0xaa, 0xb1, 0x5e, 0x57, 0x38, 0xb1, 0x1f, 0x12, 0x7f
1526                                 ],
1527                                 RecoveryId::from_i32(0).unwrap()
1528                         ).unwrap()),
1529                 };
1530
1531                 assert!(invoice.check_signature());
1532
1533                 let private_key = SecretKey::from_slice(
1534                         &[
1535                                 0xe1, 0x26, 0xf6, 0x8f, 0x7e, 0xaf, 0xcc, 0x8b, 0x74, 0xf5, 0x4d, 0x26, 0x9f, 0xe2,
1536                                 0x06, 0xbe, 0x71, 0x50, 0x00, 0xf9, 0x4d, 0xac, 0x06, 0x7d, 0x1c, 0x04, 0xa8, 0xca,
1537                                 0x3b, 0x2d, 0xb7, 0x34
1538                         ][..]
1539                 ).unwrap();
1540                 let public_key = PublicKey::from_secret_key(&Secp256k1::new(), &private_key);
1541
1542                 assert_eq!(invoice.recover_payee_pub_key(), Ok(::PayeePubKey(public_key)));
1543
1544                 let (raw_invoice, _, _) = invoice.into_parts();
1545                 let new_signed = raw_invoice.sign::<_, ()>(|hash| {
1546                         Ok(Secp256k1::new().sign_recoverable(hash, &private_key))
1547                 }).unwrap();
1548
1549                 assert!(new_signed.check_signature());
1550         }
1551
1552         #[test]
1553         fn test_check_feature_bits() {
1554                 use TaggedField::*;
1555                 use lightning::ln::features::InvoiceFeatures;
1556                 use secp256k1::Secp256k1;
1557                 use secp256k1::key::SecretKey;
1558                 use {RawInvoice, RawHrp, RawDataPart, Currency, Sha256, PositiveTimestamp, Invoice,
1559                          SemanticError};
1560
1561                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
1562                 let payment_secret = lightning::ln::PaymentSecret([21; 32]);
1563                 let invoice_template = RawInvoice {
1564                         hrp: RawHrp {
1565                                 currency: Currency::Bitcoin,
1566                                 raw_amount: None,
1567                                 si_prefix: None,
1568                         },
1569                         data: RawDataPart {
1570                                 timestamp: PositiveTimestamp::from_unix_timestamp(1496314658).unwrap(),
1571                                 tagged_fields: vec ! [
1572                                         PaymentHash(Sha256(sha256::Hash::from_hex(
1573                                                 "0001020304050607080900010203040506070809000102030405060708090102"
1574                                         ).unwrap())).into(),
1575                                         Description(
1576                                                 ::Description::new(
1577                                                         "Please consider supporting this project".to_owned()
1578                                                 ).unwrap()
1579                                         ).into(),
1580                                 ],
1581                         },
1582                 };
1583
1584                 // Missing features
1585                 let invoice = {
1586                         let mut invoice = invoice_template.clone();
1587                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1588                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_recoverable(hash, &private_key)))
1589                 }.unwrap();
1590                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::InvalidFeatures));
1591
1592                 // Missing feature bits
1593                 let invoice = {
1594                         let mut invoice = invoice_template.clone();
1595                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1596                         invoice.data.tagged_fields.push(Features(InvoiceFeatures::empty()).into());
1597                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_recoverable(hash, &private_key)))
1598                 }.unwrap();
1599                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::InvalidFeatures));
1600
1601                 // Including payment secret and feature bits
1602                 let invoice = {
1603                         let mut invoice = invoice_template.clone();
1604                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1605                         invoice.data.tagged_fields.push(Features(InvoiceFeatures::known()).into());
1606                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_recoverable(hash, &private_key)))
1607                 }.unwrap();
1608                 assert!(Invoice::from_signed(invoice).is_ok());
1609
1610                 // No payment secret or features
1611                 let invoice = {
1612                         let invoice = invoice_template.clone();
1613                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_recoverable(hash, &private_key)))
1614                 }.unwrap();
1615                 assert!(Invoice::from_signed(invoice).is_ok());
1616
1617                 // No payment secret or feature bits
1618                 let invoice = {
1619                         let mut invoice = invoice_template.clone();
1620                         invoice.data.tagged_fields.push(Features(InvoiceFeatures::empty()).into());
1621                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_recoverable(hash, &private_key)))
1622                 }.unwrap();
1623                 assert!(Invoice::from_signed(invoice).is_ok());
1624
1625                 // Missing payment secret
1626                 let invoice = {
1627                         let mut invoice = invoice_template.clone();
1628                         invoice.data.tagged_fields.push(Features(InvoiceFeatures::known()).into());
1629                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_recoverable(hash, &private_key)))
1630                 }.unwrap();
1631                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::InvalidFeatures));
1632
1633                 // Multiple payment secrets
1634                 let invoice = {
1635                         let mut invoice = invoice_template.clone();
1636                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1637                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1638                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_recoverable(hash, &private_key)))
1639                 }.unwrap();
1640                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::MultiplePaymentSecrets));
1641         }
1642
1643         #[test]
1644         fn test_builder_amount() {
1645                 use ::*;
1646
1647                 let builder = InvoiceBuilder::new(Currency::Bitcoin)
1648                         .description("Test".into())
1649                         .payment_hash(sha256::Hash::from_slice(&[0;32][..]).unwrap())
1650                         .current_timestamp();
1651
1652                 let invoice = builder.clone()
1653                         .amount_pico_btc(15000)
1654                         .build_raw()
1655                         .unwrap();
1656
1657                 assert_eq!(invoice.hrp.si_prefix, Some(SiPrefix::Nano));
1658                 assert_eq!(invoice.hrp.raw_amount, Some(15));
1659
1660
1661                 let invoice = builder.clone()
1662                         .amount_pico_btc(1500)
1663                         .build_raw()
1664                         .unwrap();
1665
1666                 assert_eq!(invoice.hrp.si_prefix, Some(SiPrefix::Pico));
1667                 assert_eq!(invoice.hrp.raw_amount, Some(1500));
1668         }
1669
1670         #[test]
1671         fn test_builder_fail() {
1672                 use ::*;
1673                 use std::iter::FromIterator;
1674                 use secp256k1::key::PublicKey;
1675
1676                 let builder = InvoiceBuilder::new(Currency::Bitcoin)
1677                         .payment_hash(sha256::Hash::from_slice(&[0;32][..]).unwrap())
1678                         .current_timestamp()
1679                         .min_final_cltv_expiry(144);
1680
1681                 let too_long_string = String::from_iter(
1682                         (0..1024).map(|_| '?')
1683                 );
1684
1685                 let long_desc_res = builder.clone()
1686                         .description(too_long_string)
1687                         .build_raw();
1688                 assert_eq!(long_desc_res, Err(CreationError::DescriptionTooLong));
1689
1690                 let route_hop = RouteHintHop {
1691                         src_node_id: PublicKey::from_slice(
1692                                         &[
1693                                                 0x03, 0x9e, 0x03, 0xa9, 0x01, 0xb8, 0x55, 0x34, 0xff, 0x1e, 0x92, 0xc4,
1694                                                 0x3c, 0x74, 0x43, 0x1f, 0x7c, 0xe7, 0x20, 0x46, 0x06, 0x0f, 0xcf, 0x7a,
1695                                                 0x95, 0xc3, 0x7e, 0x14, 0x8f, 0x78, 0xc7, 0x72, 0x55
1696                                         ][..]
1697                                 ).unwrap(),
1698                         short_channel_id: 0,
1699                         fees: RoutingFees {
1700                                 base_msat: 0,
1701                                 proportional_millionths: 0,
1702                         },
1703                         cltv_expiry_delta: 0,
1704                         htlc_minimum_msat: None,
1705                         htlc_maximum_msat: None,
1706                 };
1707                 let too_long_route = vec![route_hop; 13];
1708                 let long_route_res = builder.clone()
1709                         .description("Test".into())
1710                         .route(too_long_route)
1711                         .build_raw();
1712                 assert_eq!(long_route_res, Err(CreationError::RouteTooLong));
1713
1714                 let sign_error_res = builder.clone()
1715                         .description("Test".into())
1716                         .try_build_signed(|_| {
1717                                 Err("ImaginaryError")
1718                         });
1719                 assert_eq!(sign_error_res, Err(SignOrCreationError::SignError("ImaginaryError")));
1720         }
1721
1722         #[test]
1723         fn test_builder_ok() {
1724                 use ::*;
1725                 use secp256k1::Secp256k1;
1726                 use secp256k1::key::{SecretKey, PublicKey};
1727                 use std::time::{UNIX_EPOCH, Duration};
1728
1729                 let secp_ctx = Secp256k1::new();
1730
1731                 let private_key = SecretKey::from_slice(
1732                         &[
1733                                 0xe1, 0x26, 0xf6, 0x8f, 0x7e, 0xaf, 0xcc, 0x8b, 0x74, 0xf5, 0x4d, 0x26, 0x9f, 0xe2,
1734                                 0x06, 0xbe, 0x71, 0x50, 0x00, 0xf9, 0x4d, 0xac, 0x06, 0x7d, 0x1c, 0x04, 0xa8, 0xca,
1735                                 0x3b, 0x2d, 0xb7, 0x34
1736                         ][..]
1737                 ).unwrap();
1738                 let public_key = PublicKey::from_secret_key(&secp_ctx, &private_key);
1739
1740                 let route_1 = vec![
1741                         RouteHintHop {
1742                                 src_node_id: public_key.clone(),
1743                                 short_channel_id: de::parse_int_be(&[123; 8], 256).expect("short chan ID slice too big?"),
1744                                 fees: RoutingFees {
1745                                         base_msat: 2,
1746                                         proportional_millionths: 1,
1747                                 },
1748                                 cltv_expiry_delta: 145,
1749                                 htlc_minimum_msat: None,
1750                                 htlc_maximum_msat: None,
1751                         },
1752                         RouteHintHop {
1753                                 src_node_id: public_key.clone(),
1754                                 short_channel_id: de::parse_int_be(&[42; 8], 256).expect("short chan ID slice too big?"),
1755                                 fees: RoutingFees {
1756                                         base_msat: 3,
1757                                         proportional_millionths: 2,
1758                                 },
1759                                 cltv_expiry_delta: 146,
1760                                 htlc_minimum_msat: None,
1761                                 htlc_maximum_msat: None,
1762                         }
1763                 ];
1764
1765                 let route_2 = vec![
1766                         RouteHintHop {
1767                                 src_node_id: public_key.clone(),
1768                                 short_channel_id: 0,
1769                                 fees: RoutingFees {
1770                                         base_msat: 4,
1771                                         proportional_millionths: 3,
1772                                 },
1773                                 cltv_expiry_delta: 147,
1774                                 htlc_minimum_msat: None,
1775                                 htlc_maximum_msat: None,
1776                         },
1777                         RouteHintHop {
1778                                 src_node_id: public_key.clone(),
1779                                 short_channel_id: de::parse_int_be(&[1; 8], 256).expect("short chan ID slice too big?"),
1780                                 fees: RoutingFees {
1781                                         base_msat: 5,
1782                                         proportional_millionths: 4,
1783                                 },
1784                                 cltv_expiry_delta: 148,
1785                                 htlc_minimum_msat: None,
1786                                 htlc_maximum_msat: None,
1787                         }
1788                 ];
1789
1790                 let builder = InvoiceBuilder::new(Currency::BitcoinTestnet)
1791                         .amount_pico_btc(123)
1792                         .timestamp(UNIX_EPOCH + Duration::from_secs(1234567))
1793                         .payee_pub_key(public_key.clone())
1794                         .expiry_time(Duration::from_secs(54321))
1795                         .min_final_cltv_expiry(144)
1796                         .fallback(Fallback::PubKeyHash([0;20]))
1797                         .route(route_1.clone())
1798                         .route(route_2.clone())
1799                         .description_hash(sha256::Hash::from_slice(&[3;32][..]).unwrap())
1800                         .payment_hash(sha256::Hash::from_slice(&[21;32][..]).unwrap())
1801                         .payment_secret(PaymentSecret([42; 32]))
1802                         .basic_mpp();
1803
1804                 let invoice = builder.clone().build_signed(|hash| {
1805                         secp_ctx.sign_recoverable(hash, &private_key)
1806                 }).unwrap();
1807
1808                 assert!(invoice.check_signature().is_ok());
1809                 assert_eq!(invoice.tagged_fields().count(), 10);
1810
1811                 assert_eq!(invoice.amount_pico_btc(), Some(123));
1812                 assert_eq!(invoice.currency(), Currency::BitcoinTestnet);
1813                 assert_eq!(
1814                         invoice.timestamp().duration_since(UNIX_EPOCH).unwrap().as_secs(),
1815                         1234567
1816                 );
1817                 assert_eq!(invoice.payee_pub_key(), Some(&public_key));
1818                 assert_eq!(invoice.expiry_time(), Duration::from_secs(54321));
1819                 assert_eq!(invoice.min_final_cltv_expiry(), 144);
1820                 assert_eq!(invoice.fallbacks(), vec![&Fallback::PubKeyHash([0;20])]);
1821                 assert_eq!(invoice.routes(), vec![&RouteHint(route_1), &RouteHint(route_2)]);
1822                 assert_eq!(
1823                         invoice.description(),
1824                         InvoiceDescription::Hash(&Sha256(sha256::Hash::from_slice(&[3;32][..]).unwrap()))
1825                 );
1826                 assert_eq!(invoice.payment_hash(), &sha256::Hash::from_slice(&[21;32][..]).unwrap());
1827                 assert_eq!(invoice.payment_secret(), Some(&PaymentSecret([42; 32])));
1828                 assert_eq!(invoice.features(), Some(&InvoiceFeatures::known()));
1829
1830                 let raw_invoice = builder.build_raw().unwrap();
1831                 assert_eq!(raw_invoice, *invoice.into_signed_raw().raw_invoice())
1832         }
1833
1834         #[test]
1835         fn test_default_values() {
1836                 use ::*;
1837                 use secp256k1::Secp256k1;
1838                 use secp256k1::key::SecretKey;
1839
1840                 let signed_invoice = InvoiceBuilder::new(Currency::Bitcoin)
1841                         .description("Test".into())
1842                         .payment_hash(sha256::Hash::from_slice(&[0;32][..]).unwrap())
1843                         .current_timestamp()
1844                         .build_raw()
1845                         .unwrap()
1846                         .sign::<_, ()>(|hash| {
1847                                 let privkey = SecretKey::from_slice(&[41; 32]).unwrap();
1848                                 let secp_ctx = Secp256k1::new();
1849                                 Ok(secp_ctx.sign_recoverable(hash, &privkey))
1850                         })
1851                         .unwrap();
1852                 let invoice = Invoice::from_signed(signed_invoice).unwrap();
1853
1854                 assert_eq!(invoice.min_final_cltv_expiry(), DEFAULT_MIN_FINAL_CLTV_EXPIRY);
1855                 assert_eq!(invoice.expiry_time(), Duration::from_secs(DEFAULT_EXPIRY_TIME));
1856         }
1857 }