_ 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::RouteHint;
  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 pub const DEFAULT_EXPIRY_TIME: u64 = 3600;
  64
  65 /// Default minimum final CLTV expiry as defined by [BOLT 11].
  66 ///
  67 /// Note that this is *not* the same value as rust-lightning's minimum CLTV expiry, which is
  68 /// provided in [`MIN_FINAL_CLTV_EXPIRY`].
  69 ///
  70 /// [BOLT 11]: https://github.com/lightningnetwork/lightning-rfc/blob/master/11-payment-encoding.md
  71 /// [`MIN_FINAL_CLTV_EXPIRY`]: lightning::ln::channelmanager::MIN_FINAL_CLTV_EXPIRY
  72 pub const DEFAULT_MIN_FINAL_CLTV_EXPIRY: u64 = 18;
  73
  74 /// This function is used as a static assert for the size of `SystemTime`. If the crate fails to
  75 /// compile due to it this indicates that your system uses unexpected bounds for `SystemTime`. You
  76 /// can remove this functions and run the test `test_system_time_bounds_assumptions`. In any case,
  77 /// please open an issue. If all tests pass you should be able to use this library safely by just
  78 /// removing this function till we patch it accordingly.
  79 fn __system_time_size_check() {
  80         // Use 2 * sizeof(u64) as expected size since the expected underlying implementation is storing
  81         // a `Duration` since `SystemTime::UNIX_EPOCH`.
  82         unsafe { std::mem::transmute_copy::<SystemTime, [u8; 16]>(&UNIX_EPOCH); }
  83 }
  84
  85
  86 /// **Call this function on startup to ensure that all assumptions about the platform are valid.**
  87 ///
  88 /// Unfortunately we have to make assumptions about the upper bounds of the `SystemTime` type on
  89 /// your platform which we can't fully verify at compile time and which isn't part of it's contract.
  90 /// To our best knowledge our assumptions hold for all platforms officially supported by rust, but
  91 /// since this check is fast we recommend to do it anyway.
  92 ///
  93 /// If this function fails this is considered a bug. Please open an issue describing your
  94 /// platform and stating your current system time.
  95 ///
  96 /// # Panics
  97 /// If the check fails this function panics. By calling this function on startup you ensure that
  98 /// this wont happen at an arbitrary later point in time.
  99 pub fn check_platform() {
 100     // The upper and lower bounds of `SystemTime` are not part of its public contract and are
 101     // platform specific. That's why we have to test if our assumptions regarding these bounds
 102     // hold on the target platform.
 103     //
 104     // If this test fails on your platform, please don't use the library and open an issue
 105     // instead so we can resolve the situation. Currently this library is tested on:
 106     //   * Linux (64bit)
 107     let fail_date = UNIX_EPOCH + Duration::from_secs(SYSTEM_TIME_MAX_UNIX_TIMESTAMP);
 108     let year = Duration::from_secs(60 * 60 * 24 * 365);
 109
 110     // Make sure that the library will keep working for another year
 111     assert!(fail_date.duration_since(SystemTime::now()).unwrap() > year);
 112
 113     let max_ts = PositiveTimestamp::from_unix_timestamp(
 114         SYSTEM_TIME_MAX_UNIX_TIMESTAMP - MAX_EXPIRY_TIME
 115     ).unwrap();
 116     let max_exp = ::ExpiryTime::from_seconds(MAX_EXPIRY_TIME).unwrap();
 117
 118     assert_eq!(
 119         (*max_ts.as_time() + *max_exp.as_duration()).duration_since(UNIX_EPOCH).unwrap().as_secs(),
 120         SYSTEM_TIME_MAX_UNIX_TIMESTAMP
 121     );
 122 }
 123
 124
 125 /// Builder for `Invoice`s. It's the most convenient and advised way to use this library. It ensures
 126 /// that only a semantically and syntactically correct Invoice can be built using it.
 127 ///
 128 /// ```
 129 /// extern crate secp256k1;
 130 /// extern crate lightning_invoice;
 131 /// extern crate bitcoin_hashes;
 132 ///
 133 /// use bitcoin_hashes::Hash;
 134 /// use bitcoin_hashes::sha256;
 135 ///
 136 /// use secp256k1::Secp256k1;
 137 /// use secp256k1::key::SecretKey;
 138 ///
 139 /// use lightning_invoice::{Currency, InvoiceBuilder};
 140 ///
 141 /// # fn main() {
 142 /// let private_key = SecretKey::from_slice(
 143 ///             &[
 144 ///                     0xe1, 0x26, 0xf6, 0x8f, 0x7e, 0xaf, 0xcc, 0x8b, 0x74, 0xf5, 0x4d, 0x26, 0x9f,
 145 ///                     0xe2, 0x06, 0xbe, 0x71, 0x50, 0x00, 0xf9, 0x4d, 0xac, 0x06, 0x7d, 0x1c, 0x04,
 146 ///             0xa8, 0xca, 0x3b, 0x2d, 0xb7, 0x34
 147 ///     ][..]
 148 ///     ).unwrap();
 149 ///
 150 /// let payment_hash = sha256::Hash::from_slice(&[0; 32][..]).unwrap();
 151 ///
 152 /// let invoice = InvoiceBuilder::new(Currency::Bitcoin)
 153 ///     .description("Coins pls!".into())
 154 ///     .payment_hash(payment_hash)
 155 ///     .current_timestamp()
 156 ///     .min_final_cltv_expiry(144)
 157 ///     .build_signed(|hash| {
 158 ///             Secp256k1::new().sign_recoverable(hash, &private_key)
 159 ///     })
 160 ///     .unwrap();
 161 ///
 162 /// assert!(invoice.to_string().starts_with("lnbc1"));
 163 /// # }
 164 /// ```
 165 ///
 166 /// # Type parameters
 167 /// The two parameters `D` and `H` signal if the builder already contains the correct amount of the
 168 /// given field:
 169 ///  * `D`: exactly one `Description` or `DescriptionHash`
 170 ///  * `H`: exactly one `PaymentHash`
 171 ///  * `T`: the timestamp is set
 172 ///
 173 /// (C-not exported) as we likely need to manually select one set of boolean type parameters.
 174 #[derive(Eq, PartialEq, Debug, Clone)]
 175 pub struct InvoiceBuilder<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> {
 176         currency: Currency,
 177         amount: Option<u64>,
 178         si_prefix: Option<SiPrefix>,
 179         timestamp: Option<PositiveTimestamp>,
 180         tagged_fields: Vec<TaggedField>,
 181         error: Option<CreationError>,
 182
 183         phantom_d: std::marker::PhantomData<D>,
 184         phantom_h: std::marker::PhantomData<H>,
 185         phantom_t: std::marker::PhantomData<T>,
 186         phantom_c: std::marker::PhantomData<C>,
 187         phantom_s: std::marker::PhantomData<S>,
 188 }
 189
 190 /// Represents a syntactically and semantically correct lightning BOLT11 invoice.
 191 ///
 192 /// There are three ways to construct an `Invoice`:
 193 ///  1. using `InvoiceBuilder`
 194 ///  2. using `Invoice::from_signed(SignedRawInvoice)`
 195 ///  3. using `str::parse::<Invoice>(&str)`
 196 #[derive(Eq, PartialEq, Debug, Clone)]
 197 pub struct Invoice {
 198         signed_invoice: SignedRawInvoice,
 199 }
 200
 201 /// Represents the description of an invoice which has to be either a directly included string or
 202 /// a hash of a description provided out of band.
 203 ///
 204 /// (C-not exported) As we don't have a good way to map the reference lifetimes making this
 205 /// practically impossible to use safely in languages like C.
 206 #[derive(Eq, PartialEq, Debug, Clone)]
 207 pub enum InvoiceDescription<'f> {
 208         /// Reference to the directly supplied description in the invoice
 209         Direct(&'f Description),
 210
 211         /// Reference to the description's hash included in the invoice
 212         Hash(&'f Sha256),
 213 }
 214
 215 /// Represents a signed `RawInvoice` with cached hash. The signature is not checked and may be
 216 /// invalid.
 217 ///
 218 /// # Invariants
 219 /// The hash has to be either from the deserialized invoice or from the serialized `raw_invoice`.
 220 #[derive(Eq, PartialEq, Debug, Clone)]
 221 pub struct SignedRawInvoice {
 222         /// The rawInvoice that the signature belongs to
 223         raw_invoice: RawInvoice,
 224
 225         /// Hash of the `RawInvoice` that will be used to check the signature.
 226         ///
 227         /// * if the `SignedRawInvoice` was deserialized the hash is of from the original encoded form,
 228         /// since it's not guaranteed that encoding it again will lead to the same result since integers
 229         /// could have been encoded with leading zeroes etc.
 230         /// * if the `SignedRawInvoice` was constructed manually the hash will be the calculated hash
 231         /// from the `RawInvoice`
 232         hash: [u8; 32],
 233
 234         /// signature of the payment request
 235         signature: InvoiceSignature,
 236 }
 237
 238 /// Represents an syntactically correct Invoice for a payment on the lightning network,
 239 /// but without the signature information.
 240 /// De- and encoding should not lead to information loss but may lead to different hashes.
 241 ///
 242 /// For methods without docs see the corresponding methods in `Invoice`.
 243 #[derive(Eq, PartialEq, Debug, Clone)]
 244 pub struct RawInvoice {
 245         /// human readable part
 246         pub hrp: RawHrp,
 247
 248         /// data part
 249         pub data: RawDataPart,
 250 }
 251
 252 /// Data of the `RawInvoice` that is encoded in the human readable part
 253 ///
 254 /// (C-not exported) As we don't yet support Option<Enum>
 255 #[derive(Eq, PartialEq, Debug, Clone)]
 256 pub struct RawHrp {
 257         /// The currency deferred from the 3rd and 4th character of the bech32 transaction
 258         pub currency: Currency,
 259
 260         /// The amount that, multiplied by the SI prefix, has to be payed
 261         pub raw_amount: Option<u64>,
 262
 263         /// SI prefix that gets multiplied with the `raw_amount`
 264         pub si_prefix: Option<SiPrefix>,
 265 }
 266
 267 /// Data of the `RawInvoice` that is encoded in the data part
 268 #[derive(Eq, PartialEq, Debug, Clone)]
 269 pub struct RawDataPart {
 270         /// generation time of the invoice
 271         pub timestamp: PositiveTimestamp,
 272
 273         /// tagged fields of the payment request
 274         pub tagged_fields: Vec<RawTaggedField>,
 275 }
 276
 277 /// A timestamp that refers to a date after 1 January 1970 which means its representation as UNIX
 278 /// timestamp is positive.
 279 ///
 280 /// # Invariants
 281 /// The UNIX timestamp representing the stored time has to be positive and small enough so that
 282 /// a `EpiryTime` can be added to it without an overflow.
 283 #[derive(Eq, PartialEq, Debug, Clone)]
 284 pub struct PositiveTimestamp(SystemTime);
 285
 286 /// SI prefixes for the human readable part
 287 #[derive(Eq, PartialEq, Debug, Clone, Copy)]
 288 pub enum SiPrefix {
 289         /// 10^-3
 290         Milli,
 291         /// 10^-6
 292         Micro,
 293         /// 10^-9
 294         Nano,
 295         /// 10^-12
 296         Pico,
 297 }
 298
 299 impl SiPrefix {
 300         /// Returns the multiplier to go from a BTC value to picoBTC implied by this SiPrefix.
 301         /// This is effectively 10^12 * the prefix multiplier
 302         pub fn multiplier(&self) -> u64 {
 303                 match *self {
 304                         SiPrefix::Milli => 1_000_000_000,
 305                         SiPrefix::Micro => 1_000_000,
 306                         SiPrefix::Nano => 1_000,
 307                         SiPrefix::Pico => 1,
 308                 }
 309         }
 310
 311         /// Returns all enum variants of `SiPrefix` sorted in descending order of their associated
 312         /// multiplier.
 313         ///
 314         /// (C-not exported) As we don't yet support a slice of enums, and also because this function
 315         /// isn't the most critical to expose.
 316         pub fn values_desc() -> &'static [SiPrefix] {
 317                 use SiPrefix::*;
 318                 static VALUES: [SiPrefix; 4] = [Milli, Micro, Nano, Pico];
 319                 &VALUES
 320         }
 321 }
 322
 323 /// Enum representing the crypto currencies (or networks) supported by this library
 324 #[derive(Eq, PartialEq, Debug, Clone)]
 325 pub enum Currency {
 326         /// Bitcoin mainnet
 327         Bitcoin,
 328
 329         /// Bitcoin testnet
 330         BitcoinTestnet,
 331
 332         /// Bitcoin regtest
 333         Regtest,
 334
 335         /// Bitcoin simnet
 336         Simnet,
 337
 338         /// Bitcoin signet
 339         Signet,
 340 }
 341
 342 /// Tagged field which may have an unknown tag
 343 ///
 344 /// (C-not exported) as we don't currently support TaggedField
 345 #[derive(Eq, PartialEq, Debug, Clone)]
 346 pub enum RawTaggedField {
 347         /// Parsed tagged field with known tag
 348         KnownSemantics(TaggedField),
 349         /// tagged field which was not parsed due to an unknown tag or undefined field semantics
 350         UnknownSemantics(Vec<u5>),
 351 }
 352
 353 /// Tagged field with known tag
 354 ///
 355 /// For descriptions of the enum values please refer to the enclosed type's docs.
 356 ///
 357 /// (C-not exported) As we don't yet support enum variants with the same name the struct contained
 358 /// in the variant.
 359 #[allow(missing_docs)]
 360 #[derive(Eq, PartialEq, Debug, Clone)]
 361 pub enum TaggedField {
 362         PaymentHash(Sha256),
 363         Description(Description),
 364         PayeePubKey(PayeePubKey),
 365         DescriptionHash(Sha256),
 366         ExpiryTime(ExpiryTime),
 367         MinFinalCltvExpiry(MinFinalCltvExpiry),
 368         Fallback(Fallback),
 369         PrivateRoute(PrivateRoute),
 370         PaymentSecret(PaymentSecret),
 371         Features(InvoiceFeatures),
 372 }
 373
 374 /// SHA-256 hash
 375 #[derive(Eq, PartialEq, Debug, Clone)]
 376 pub struct Sha256(pub sha256::Hash);
 377
 378 /// Description string
 379 ///
 380 /// # Invariants
 381 /// The description can be at most 639 __bytes__ long
 382 #[derive(Eq, PartialEq, Debug, Clone)]
 383 pub struct Description(String);
 384
 385 /// Payee public key
 386 #[derive(Eq, PartialEq, Debug, Clone)]
 387 pub struct PayeePubKey(pub PublicKey);
 388
 389 /// Positive duration that defines when (relatively to the timestamp) in the future the invoice
 390 /// expires
 391 ///
 392 /// # Invariants
 393 /// The number of seconds this expiry time represents has to be in the range
 394 /// `0...(SYSTEM_TIME_MAX_UNIX_TIMESTAMP - MAX_EXPIRY_TIME)` to avoid overflows when adding it to a
 395 /// timestamp
 396 #[derive(Eq, PartialEq, Debug, Clone)]
 397 pub struct ExpiryTime(Duration);
 398
 399 /// `min_final_cltv_expiry` to use for the last HTLC in the route
 400 #[derive(Eq, PartialEq, Debug, Clone)]
 401 pub struct MinFinalCltvExpiry(pub u64);
 402
 403 // TODO: better types instead onf byte arrays
 404 /// Fallback address in case no LN payment is possible
 405 #[allow(missing_docs)]
 406 #[derive(Eq, PartialEq, Debug, Clone)]
 407 pub enum Fallback {
 408         SegWitProgram {
 409                 version: u5,
 410                 program: Vec<u8>,
 411         },
 412         PubKeyHash([u8; 20]),
 413         ScriptHash([u8; 20]),
 414 }
 415
 416 /// Recoverable signature
 417 #[derive(Eq, PartialEq, Debug, Clone)]
 418 pub struct InvoiceSignature(pub RecoverableSignature);
 419
 420 /// Private routing information
 421 ///
 422 /// # Invariants
 423 /// The encoded route has to be <1024 5bit characters long (<=639 bytes or <=12 hops)
 424 ///
 425 #[derive(Eq, PartialEq, Debug, Clone)]
 426 pub struct PrivateRoute(RouteHint);
 427
 428 /// Tag constants as specified in BOLT11
 429 #[allow(missing_docs)]
 430 pub mod constants {
 431         pub const TAG_PAYMENT_HASH: u8 = 1;
 432         pub const TAG_DESCRIPTION: u8 = 13;
 433         pub const TAG_PAYEE_PUB_KEY: u8 = 19;
 434         pub const TAG_DESCRIPTION_HASH: u8 = 23;
 435         pub const TAG_EXPIRY_TIME: u8 = 6;
 436         pub const TAG_MIN_FINAL_CLTV_EXPIRY: u8 = 24;
 437         pub const TAG_FALLBACK: u8 = 9;
 438         pub const TAG_PRIVATE_ROUTE: u8 = 3;
 439         pub const TAG_PAYMENT_SECRET: u8 = 16;
 440         pub const TAG_FEATURES: u8 = 5;
 441 }
 442
 443 impl InvoiceBuilder<tb::False, tb::False, tb::False, tb::False, tb::False> {
 444         /// Construct new, empty `InvoiceBuilder`. All necessary fields have to be filled first before
 445         /// `InvoiceBuilder::build(self)` becomes available.
 446         pub fn new(currrency: Currency) -> Self {
 447                 InvoiceBuilder {
 448                         currency: currrency,
 449                         amount: None,
 450                         si_prefix: None,
 451                         timestamp: None,
 452                         tagged_fields: Vec::new(),
 453                         error: None,
 454
 455                         phantom_d: std::marker::PhantomData,
 456                         phantom_h: std::marker::PhantomData,
 457                         phantom_t: std::marker::PhantomData,
 458                         phantom_c: std::marker::PhantomData,
 459                         phantom_s: std::marker::PhantomData,
 460                 }
 461         }
 462 }
 463
 464 impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, T, C, S> {
 465         /// Helper function to set the completeness flags.
 466         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> {
 467                 InvoiceBuilder::<DN, HN, TN, CN, SN> {
 468                         currency: self.currency,
 469                         amount: self.amount,
 470                         si_prefix: self.si_prefix,
 471                         timestamp: self.timestamp,
 472                         tagged_fields: self.tagged_fields,
 473                         error: self.error,
 474
 475                         phantom_d: std::marker::PhantomData,
 476                         phantom_h: std::marker::PhantomData,
 477                         phantom_t: std::marker::PhantomData,
 478                         phantom_c: std::marker::PhantomData,
 479                         phantom_s: std::marker::PhantomData,
 480                 }
 481         }
 482
 483         /// Sets the amount in pico BTC. The optimal SI prefix is choosen automatically.
 484         pub fn amount_pico_btc(mut self, amount: u64) -> Self {
 485                 let biggest_possible_si_prefix = SiPrefix::values_desc()
 486                         .iter()
 487                         .find(|prefix| amount % prefix.multiplier() == 0)
 488                         .expect("Pico should always match");
 489                 self.amount = Some(amount / biggest_possible_si_prefix.multiplier());
 490                 self.si_prefix = Some(*biggest_possible_si_prefix);
 491                 self
 492         }
 493
 494         /// Sets the payee's public key.
 495         pub fn payee_pub_key(mut self, pub_key: PublicKey) -> Self {
 496                 self.tagged_fields.push(TaggedField::PayeePubKey(PayeePubKey(pub_key)));
 497                 self
 498         }
 499
 500         /// Sets the expiry time
 501         pub fn expiry_time(mut self, expiry_time: Duration) -> Self {
 502         match ExpiryTime::from_duration(expiry_time) {
 503             Ok(t) => self.tagged_fields.push(TaggedField::ExpiryTime(t)),
 504             Err(e) => self.error = Some(e),
 505         };
 506                 self
 507         }
 508
 509         /// Adds a fallback address.
 510         pub fn fallback(mut self, fallback: Fallback) -> Self {
 511                 self.tagged_fields.push(TaggedField::Fallback(fallback));
 512                 self
 513         }
 514
 515         /// Adds a private route.
 516         pub fn private_route(mut self, hint: RouteHint) -> Self {
 517                 match PrivateRoute::new(hint) {
 518                         Ok(r) => self.tagged_fields.push(TaggedField::PrivateRoute(r)),
 519                         Err(e) => self.error = Some(e),
 520                 }
 521                 self
 522         }
 523 }
 524
 525 impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, tb::True, C, S> {
 526         /// Builds a `RawInvoice` if no `CreationError` occurred while construction any of the fields.
 527         pub fn build_raw(self) -> Result<RawInvoice, CreationError> {
 528
 529                 // If an error occurred at any time before, return it now
 530                 if let Some(e) = self.error {
 531                         return Err(e);
 532                 }
 533
 534                 let hrp = RawHrp {
 535                         currency: self.currency,
 536                         raw_amount: self.amount,
 537                         si_prefix: self.si_prefix,
 538                 };
 539
 540                 let timestamp = self.timestamp.expect("ensured to be Some(t) by type T");
 541
 542                 let tagged_fields = self.tagged_fields.into_iter().map(|tf| {
 543                         RawTaggedField::KnownSemantics(tf)
 544                 }).collect::<Vec<_>>();
 545
 546                 let data = RawDataPart {
 547                         timestamp: timestamp,
 548                         tagged_fields: tagged_fields,
 549                 };
 550
 551                 Ok(RawInvoice {
 552                         hrp: hrp,
 553                         data: data,
 554                 })
 555         }
 556 }
 557
 558 impl<H: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<tb::False, H, T, C, S> {
 559         /// Set the description. This function is only available if no description (hash) was set.
 560         pub fn description(mut self, description: String) -> InvoiceBuilder<tb::True, H, T, C, S> {
 561                 match Description::new(description) {
 562                         Ok(d) => self.tagged_fields.push(TaggedField::Description(d)),
 563                         Err(e) => self.error = Some(e),
 564                 }
 565                 self.set_flags()
 566         }
 567
 568         /// Set the description hash. This function is only available if no description (hash) was set.
 569         pub fn description_hash(mut self, description_hash: sha256::Hash) -> InvoiceBuilder<tb::True, H, T, C, S> {
 570                 self.tagged_fields.push(TaggedField::DescriptionHash(Sha256(description_hash)));
 571                 self.set_flags()
 572         }
 573 }
 574
 575 impl<D: tb::Bool, T: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, tb::False, T, C, S> {
 576         /// Set the payment hash. This function is only available if no payment hash was set.
 577         pub fn payment_hash(mut self, hash: sha256::Hash) -> InvoiceBuilder<D, tb::True, T, C, S> {
 578                 self.tagged_fields.push(TaggedField::PaymentHash(Sha256(hash)));
 579                 self.set_flags()
 580         }
 581 }
 582
 583 impl<D: tb::Bool, H: tb::Bool, C: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, tb::False, C, S> {
 584         /// Sets the timestamp.
 585         pub fn timestamp(mut self, time: SystemTime) -> InvoiceBuilder<D, H, tb::True, C, S> {
 586                 match PositiveTimestamp::from_system_time(time) {
 587                         Ok(t) => self.timestamp = Some(t),
 588                         Err(e) => self.error = Some(e),
 589                 }
 590
 591                 self.set_flags()
 592         }
 593
 594         /// Sets the timestamp to the current UNIX timestamp.
 595         pub fn current_timestamp(mut self) -> InvoiceBuilder<D, H, tb::True, C, S> {
 596                 let now = PositiveTimestamp::from_system_time(SystemTime::now());
 597                 self.timestamp = Some(now.expect("for the foreseeable future this shouldn't happen"));
 598                 self.set_flags()
 599         }
 600 }
 601
 602 impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, S: tb::Bool> InvoiceBuilder<D, H, T, tb::False, S> {
 603         /// Sets `min_final_cltv_expiry`.
 604         pub fn min_final_cltv_expiry(mut self, min_final_cltv_expiry: u64) -> InvoiceBuilder<D, H, T, tb::True, S> {
 605                 self.tagged_fields.push(TaggedField::MinFinalCltvExpiry(MinFinalCltvExpiry(min_final_cltv_expiry)));
 606                 self.set_flags()
 607         }
 608 }
 609
 610 impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, T, C, tb::False> {
 611         /// Sets the payment secret and relevant features.
 612         pub fn payment_secret(mut self, payment_secret: PaymentSecret) -> InvoiceBuilder<D, H, T, C, tb::True> {
 613                 let features = InvoiceFeatures::empty()
 614                         .set_variable_length_onion_required()
 615                         .set_payment_secret_required();
 616                 self.tagged_fields.push(TaggedField::PaymentSecret(payment_secret));
 617                 self.tagged_fields.push(TaggedField::Features(features));
 618                 self.set_flags()
 619         }
 620 }
 621
 622 impl<D: tb::Bool, H: tb::Bool, T: tb::Bool, C: tb::Bool> InvoiceBuilder<D, H, T, C, tb::True> {
 623         /// Sets the `basic_mpp` feature as optional.
 624         pub fn basic_mpp(mut self) -> Self {
 625                 self.tagged_fields = self.tagged_fields
 626                         .drain(..)
 627                         .map(|field| match field {
 628                                 TaggedField::Features(f) => TaggedField::Features(f.set_basic_mpp_optional()),
 629                                 _ => field,
 630                         })
 631                         .collect();
 632                 self
 633         }
 634 }
 635
 636 impl<S: tb::Bool> InvoiceBuilder<tb::True, tb::True, tb::True, tb::True, S> {
 637         /// Builds and signs an invoice using the supplied `sign_function`. This function MAY NOT fail
 638         /// and MUST produce a recoverable signature valid for the given hash and if applicable also for
 639         /// the included payee public key.
 640         pub fn build_signed<F>(self, sign_function: F) -> Result<Invoice, CreationError>
 641                 where F: FnOnce(&Message) -> RecoverableSignature
 642         {
 643                 let invoice = self.try_build_signed::<_, ()>(|hash| {
 644                         Ok(sign_function(hash))
 645                 });
 646
 647                 match invoice {
 648                         Ok(i) => Ok(i),
 649                         Err(SignOrCreationError::CreationError(e)) => Err(e),
 650                         Err(SignOrCreationError::SignError(())) => unreachable!(),
 651                 }
 652         }
 653
 654         /// Builds and signs an invoice using the supplied `sign_function`. This function MAY fail with
 655         /// an error of type `E` and MUST produce a recoverable signature valid for the given hash and
 656         /// if applicable also for the included payee public key.
 657         pub fn try_build_signed<F, E>(self, sign_function: F) -> Result<Invoice, SignOrCreationError<E>>
 658                 where F: FnOnce(&Message) -> Result<RecoverableSignature, E>
 659         {
 660                 let raw = match self.build_raw() {
 661                         Ok(r) => r,
 662                         Err(e) => return Err(SignOrCreationError::CreationError(e)),
 663                 };
 664
 665                 let signed = match raw.sign(sign_function) {
 666                         Ok(s) => s,
 667                         Err(e) => return Err(SignOrCreationError::SignError(e)),
 668                 };
 669
 670                 let invoice = Invoice {
 671                         signed_invoice: signed,
 672                 };
 673
 674                 invoice.check_field_counts().expect("should be ensured by type signature of builder");
 675                 invoice.check_feature_bits().expect("should be ensured by type signature of builder");
 676
 677                 Ok(invoice)
 678         }
 679 }
 680
 681
 682 impl SignedRawInvoice {
 683         /// Disassembles the `SignedRawInvoice` into its three parts:
 684         ///  1. raw invoice
 685         ///  2. hash of the raw invoice
 686         ///  3. signature
 687         pub fn into_parts(self) -> (RawInvoice, [u8; 32], InvoiceSignature) {
 688                 (self.raw_invoice, self.hash, self.signature)
 689         }
 690
 691         /// The `RawInvoice` which was signed.
 692         pub fn raw_invoice(&self) -> &RawInvoice {
 693                 &self.raw_invoice
 694         }
 695
 696         /// The hash of the `RawInvoice` that was signed.
 697         pub fn hash(&self) -> &[u8; 32] {
 698                 &self.hash
 699         }
 700
 701         /// InvoiceSignature for the invoice.
 702         pub fn signature(&self) -> &InvoiceSignature {
 703                 &self.signature
 704         }
 705
 706         /// Recovers the public key used for signing the invoice from the recoverable signature.
 707         pub fn recover_payee_pub_key(&self) -> Result<PayeePubKey, secp256k1::Error> {
 708                 let hash = Message::from_slice(&self.hash[..])
 709                         .expect("Hash is 32 bytes long, same as MESSAGE_SIZE");
 710
 711                 Ok(PayeePubKey(Secp256k1::new().recover(
 712                         &hash,
 713                         &self.signature
 714                 )?))
 715         }
 716
 717         /// Checks if the signature is valid for the included payee public key or if none exists if it's
 718         /// valid for the recovered signature (which should always be true?).
 719         pub fn check_signature(&self) -> bool {
 720                 let included_pub_key = self.raw_invoice.payee_pub_key();
 721
 722                 let mut recovered_pub_key = Option::None;
 723                 if recovered_pub_key.is_none() {
 724                         let recovered = match self.recover_payee_pub_key() {
 725                                 Ok(pk) => pk,
 726                                 Err(_) => return false,
 727                         };
 728                         recovered_pub_key = Some(recovered);
 729                 }
 730
 731                 let pub_key = included_pub_key.or_else(|| recovered_pub_key.as_ref())
 732                         .expect("One is always present");
 733
 734                 let hash = Message::from_slice(&self.hash[..])
 735                         .expect("Hash is 32 bytes long, same as MESSAGE_SIZE");
 736
 737                 let secp_context = Secp256k1::new();
 738                 let verification_result = secp_context.verify(
 739                         &hash,
 740                         &self.signature.to_standard(),
 741                         pub_key
 742                 );
 743
 744                 match verification_result {
 745                         Ok(()) => true,
 746                         Err(_) => false,
 747                 }
 748         }
 749 }
 750
 751 /// Finds the first element of an enum stream of a given variant and extracts one member of the
 752 /// variant. If no element was found `None` gets returned.
 753 ///
 754 /// The following example would extract the first B.
 755 /// ```
 756 /// use Enum::*
 757 ///
 758 /// enum Enum {
 759 ///     A(u8),
 760 ///     B(u16)
 761 /// }
 762 ///
 763 /// let elements = vec![A(1), A(2), B(3), A(4)]
 764 ///
 765 /// assert_eq!(find_extract!(elements.iter(), Enum::B(ref x), x), Some(3u16))
 766 /// ```
 767 macro_rules! find_extract {
 768         ($iter:expr, $enm:pat, $enm_var:ident) => {
 769                 find_all_extract!($iter, $enm, $enm_var).next()
 770     };
 771 }
 772
 773 /// Finds the all elements of an enum stream of a given variant and extracts one member of the
 774 /// variant through an iterator.
 775 ///
 776 /// The following example would extract all A.
 777 /// ```
 778 /// use Enum::*
 779 ///
 780 /// enum Enum {
 781 ///     A(u8),
 782 ///     B(u16)
 783 /// }
 784 ///
 785 /// let elements = vec![A(1), A(2), B(3), A(4)]
 786 ///
 787 /// assert_eq!(
 788 ///     find_all_extract!(elements.iter(), Enum::A(ref x), x).collect::<Vec<u8>>(),
 789 ///     vec![1u8, 2u8, 4u8])
 790 /// ```
 791 macro_rules! find_all_extract {
 792         ($iter:expr, $enm:pat, $enm_var:ident) => {
 793         $iter.filter_map(|tf| match *tf {
 794                         $enm => Some($enm_var),
 795                         _ => None,
 796                 })
 797     };
 798 }
 799
 800 #[allow(missing_docs)]
 801 impl RawInvoice {
 802         /// Construct the invoice's HRP and signatureless data into a preimage to be hashed.
 803         pub(crate) fn construct_invoice_preimage(hrp_bytes: &[u8], data_without_signature: &[u5]) -> Vec<u8> {
 804                 use bech32::FromBase32;
 805
 806                 let mut preimage = Vec::<u8>::from(hrp_bytes);
 807
 808                 let mut data_part = Vec::from(data_without_signature);
 809                 let overhang = (data_part.len() * 5) % 8;
 810                 if overhang > 0 {
 811                         // add padding if data does not end at a byte boundary
 812                         data_part.push(u5::try_from_u8(0).unwrap());
 813
 814                         // if overhang is in (1..3) we need to add u5(0) padding two times
 815                         if overhang < 3 {
 816                                 data_part.push(u5::try_from_u8(0).unwrap());
 817                         }
 818                 }
 819
 820                 preimage.extend_from_slice(&Vec::<u8>::from_base32(&data_part)
 821                         .expect("No padding error may occur due to appended zero above."));
 822                 preimage
 823         }
 824
 825         /// Hash the HRP as bytes and signatureless data part.
 826         fn hash_from_parts(hrp_bytes: &[u8], data_without_signature: &[u5]) -> [u8; 32] {
 827                 let preimage = RawInvoice::construct_invoice_preimage(hrp_bytes, data_without_signature);
 828                 let mut hash: [u8; 32] = Default::default();
 829                 hash.copy_from_slice(&sha256::Hash::hash(&preimage)[..]);
 830                 hash
 831         }
 832
 833         /// Calculate the hash of the encoded `RawInvoice`
 834         pub fn hash(&self) -> [u8; 32] {
 835                 use bech32::ToBase32;
 836
 837                 RawInvoice::hash_from_parts(
 838                         self.hrp.to_string().as_bytes(),
 839                         &self.data.to_base32()
 840                 )
 841         }
 842
 843         /// Signs the invoice using the supplied `sign_function`. This function MAY fail with an error
 844         /// of type `E`. Since the signature of a `SignedRawInvoice` is not required to be valid there
 845         /// are no constraints regarding the validity of the produced signature.
 846         ///
 847         /// (C-not exported) As we don't currently support passing function pointers into methods
 848         /// explicitly.
 849         pub fn sign<F, E>(self, sign_method: F) -> Result<SignedRawInvoice, E>
 850                 where F: FnOnce(&Message) -> Result<RecoverableSignature, E>
 851         {
 852                 let raw_hash = self.hash();
 853                 let hash = Message::from_slice(&raw_hash[..])
 854                         .expect("Hash is 32 bytes long, same as MESSAGE_SIZE");
 855                 let signature = sign_method(&hash)?;
 856
 857                 Ok(SignedRawInvoice {
 858                         raw_invoice: self,
 859                         hash: raw_hash,
 860                         signature: InvoiceSignature(signature),
 861                 })
 862         }
 863
 864         /// Returns an iterator over all tagged fields with known semantics.
 865         ///
 866         /// (C-not exported) As there is not yet a manual mapping for a FilterMap
 867         pub fn known_tagged_fields(&self)
 868                 -> FilterMap<Iter<RawTaggedField>, fn(&RawTaggedField) -> Option<&TaggedField>>
 869         {
 870                 // For 1.14.0 compatibility: closures' types can't be written an fn()->() in the
 871                 // function's type signature.
 872                 // TODO: refactor once impl Trait is available
 873                 fn match_raw(raw: &RawTaggedField) -> Option<&TaggedField> {
 874                         match *raw {
 875                                 RawTaggedField::KnownSemantics(ref tf) => Some(tf),
 876                                 _ => None,
 877                         }
 878                 }
 879
 880                 self.data.tagged_fields.iter().filter_map(match_raw )
 881         }
 882
 883         pub fn payment_hash(&self) -> Option<&Sha256> {
 884                 find_extract!(self.known_tagged_fields(), TaggedField::PaymentHash(ref x), x)
 885         }
 886
 887         pub fn description(&self) -> Option<&Description> {
 888                 find_extract!(self.known_tagged_fields(), TaggedField::Description(ref x), x)
 889         }
 890
 891         pub fn payee_pub_key(&self) -> Option<&PayeePubKey> {
 892                 find_extract!(self.known_tagged_fields(), TaggedField::PayeePubKey(ref x), x)
 893         }
 894
 895         pub fn description_hash(&self) -> Option<&Sha256> {
 896                 find_extract!(self.known_tagged_fields(), TaggedField::DescriptionHash(ref x), x)
 897         }
 898
 899         pub fn expiry_time(&self) -> Option<&ExpiryTime> {
 900                 find_extract!(self.known_tagged_fields(), TaggedField::ExpiryTime(ref x), x)
 901         }
 902
 903         pub fn min_final_cltv_expiry(&self) -> Option<&MinFinalCltvExpiry> {
 904                 find_extract!(self.known_tagged_fields(), TaggedField::MinFinalCltvExpiry(ref x), x)
 905         }
 906
 907         pub fn payment_secret(&self) -> Option<&PaymentSecret> {
 908                 find_extract!(self.known_tagged_fields(), TaggedField::PaymentSecret(ref x), x)
 909         }
 910
 911         pub fn features(&self) -> Option<&InvoiceFeatures> {
 912                 find_extract!(self.known_tagged_fields(), TaggedField::Features(ref x), x)
 913         }
 914
 915         /// (C-not exported) as we don't support Vec<&NonOpaqueType>
 916         pub fn fallbacks(&self) -> Vec<&Fallback> {
 917                 find_all_extract!(self.known_tagged_fields(), TaggedField::Fallback(ref x), x).collect()
 918         }
 919
 920         pub fn private_routes(&self) -> Vec<&PrivateRoute> {
 921                 find_all_extract!(self.known_tagged_fields(), TaggedField::PrivateRoute(ref x), x).collect()
 922         }
 923
 924         pub fn amount_pico_btc(&self) -> Option<u64> {
 925                 self.hrp.raw_amount.map(|v| {
 926                         v * self.hrp.si_prefix.as_ref().map_or(1_000_000_000_000, |si| { si.multiplier() })
 927                 })
 928         }
 929
 930         pub fn currency(&self) -> Currency {
 931                 self.hrp.currency.clone()
 932         }
 933 }
 934
 935 impl PositiveTimestamp {
 936         /// Create a new `PositiveTimestamp` from a unix timestamp in the Range
 937         /// `0...SYSTEM_TIME_MAX_UNIX_TIMESTAMP - MAX_EXPIRY_TIME`, otherwise return a
 938         /// `CreationError::TimestampOutOfBounds`.
 939         pub fn from_unix_timestamp(unix_seconds: u64) -> Result<Self, CreationError> {
 940                 if unix_seconds > SYSTEM_TIME_MAX_UNIX_TIMESTAMP - MAX_EXPIRY_TIME {
 941                         Err(CreationError::TimestampOutOfBounds)
 942                 } else {
 943                         Ok(PositiveTimestamp(UNIX_EPOCH + Duration::from_secs(unix_seconds)))
 944                 }
 945         }
 946
 947         /// Create a new `PositiveTimestamp` from a `SystemTime` with a corresponding unix timestamp in
 948         /// the Range `0...SYSTEM_TIME_MAX_UNIX_TIMESTAMP - MAX_EXPIRY_TIME`, otherwise return a
 949         /// `CreationError::TimestampOutOfBounds`.
 950         pub fn from_system_time(time: SystemTime) -> Result<Self, CreationError> {
 951                 if time
 952                         .duration_since(UNIX_EPOCH)
 953                         .map(|t| t.as_secs() <= SYSTEM_TIME_MAX_UNIX_TIMESTAMP - MAX_EXPIRY_TIME)
 954                         .unwrap_or(true)
 955                         {
 956                                 Ok(PositiveTimestamp(time))
 957                         } else {
 958                         Err(CreationError::TimestampOutOfBounds)
 959                 }
 960         }
 961
 962         /// Returns the UNIX timestamp representing the stored time
 963         pub fn as_unix_timestamp(&self) -> u64 {
 964                 self.0.duration_since(UNIX_EPOCH)
 965                         .expect("ensured by type contract/constructors")
 966                         .as_secs()
 967         }
 968
 969         /// Returns a reference to the internal `SystemTime` time representation
 970         pub fn as_time(&self) -> &SystemTime {
 971                 &self.0
 972         }
 973 }
 974
 975 impl Into<SystemTime> for PositiveTimestamp {
 976         fn into(self) -> SystemTime {
 977                 self.0
 978         }
 979 }
 980
 981 impl Deref for PositiveTimestamp {
 982         type Target = SystemTime;
 983
 984         fn deref(&self) -> &Self::Target {
 985                 &self.0
 986         }
 987 }
 988
 989 impl Invoice {
 990         /// Transform the `Invoice` into it's unchecked version
 991         pub fn into_signed_raw(self) -> SignedRawInvoice {
 992                 self.signed_invoice
 993         }
 994
 995         /// Check that all mandatory fields are present
 996         fn check_field_counts(&self) -> Result<(), SemanticError> {
 997                 // "A writer MUST include exactly one p field […]."
 998                 let payment_hash_cnt = self.tagged_fields().filter(|&tf| match *tf {
 999                         TaggedField::PaymentHash(_) => true,
1000                         _ => false,
1001                 }).count();
1002                 if payment_hash_cnt < 1 {
1003                         return Err(SemanticError::NoPaymentHash);
1004                 } else if payment_hash_cnt > 1 {
1005                         return Err(SemanticError::MultiplePaymentHashes);
1006                 }
1007
1008                 // "A writer MUST include either exactly one d or exactly one h field."
1009                 let description_cnt = self.tagged_fields().filter(|&tf| match *tf {
1010                         TaggedField::Description(_) | TaggedField::DescriptionHash(_) => true,
1011                         _ => false,
1012                 }).count();
1013                 if  description_cnt < 1 {
1014                         return Err(SemanticError::NoDescription);
1015                 } else if description_cnt > 1 {
1016                         return  Err(SemanticError::MultipleDescriptions);
1017                 }
1018
1019                 Ok(())
1020         }
1021
1022         /// Check that feature bits are set as required
1023         fn check_feature_bits(&self) -> Result<(), SemanticError> {
1024                 // "If the payment_secret feature is set, MUST include exactly one s field."
1025                 let payment_secret_count = self.tagged_fields().filter(|&tf| match *tf {
1026                         TaggedField::PaymentSecret(_) => true,
1027                         _ => false,
1028                 }).count();
1029                 if payment_secret_count > 1 {
1030                         return Err(SemanticError::MultiplePaymentSecrets);
1031                 }
1032
1033                 // "A writer MUST set an s field if and only if the payment_secret feature is set."
1034                 let has_payment_secret = payment_secret_count == 1;
1035                 let features = self.tagged_fields().find(|&tf| match *tf {
1036                         TaggedField::Features(_) => true,
1037                         _ => false,
1038                 });
1039                 match features {
1040                         None if has_payment_secret => Err(SemanticError::InvalidFeatures),
1041                         None => Ok(()),
1042                         Some(TaggedField::Features(features)) => {
1043                                 if features.supports_payment_secret() && has_payment_secret {
1044                                         Ok(())
1045                                 } else if has_payment_secret {
1046                                         Err(SemanticError::InvalidFeatures)
1047                                 } else if features.supports_payment_secret() {
1048                                         Err(SemanticError::InvalidFeatures)
1049                                 } else {
1050                                         Ok(())
1051                                 }
1052                         },
1053                         Some(_) => unreachable!(),
1054                 }
1055         }
1056
1057         /// Check that the invoice is signed correctly and that key recovery works
1058         pub fn check_signature(&self) -> Result<(), SemanticError> {
1059                 match self.signed_invoice.recover_payee_pub_key() {
1060                         Err(secp256k1::Error::InvalidRecoveryId) =>
1061                                 return Err(SemanticError::InvalidRecoveryId),
1062                         Err(_) => panic!("no other error may occur"),
1063                         Ok(_) => {},
1064                 }
1065
1066                 if !self.signed_invoice.check_signature() {
1067                         return Err(SemanticError::InvalidSignature);
1068                 }
1069
1070                 Ok(())
1071         }
1072
1073         /// Constructs an `Invoice` from a `SignedRawInvoice` by checking all its invariants.
1074         /// ```
1075         /// use lightning_invoice::*;
1076         ///
1077         /// let invoice = "lnbc1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdp\
1078         ///     l2pkx2ctnv5sxxmmwwd5kgetjypeh2ursdae8g6twvus8g6rfwvs8qun0dfjkxaq8rkx3yf5tcsyz3d7\
1079         ///     3gafnh3cax9rn449d9p5uxz9ezhhypd0elx87sjle52x86fux2ypatgddc6k63n7erqz25le42c4u4ec\
1080         ///     ky03ylcqca784w";
1081         ///
1082         /// let signed = invoice.parse::<SignedRawInvoice>().unwrap();
1083         ///
1084         /// assert!(Invoice::from_signed(signed).is_ok());
1085         /// ```
1086         pub fn from_signed(signed_invoice: SignedRawInvoice) -> Result<Self, SemanticError> {
1087                 let invoice = Invoice {
1088                         signed_invoice: signed_invoice,
1089                 };
1090                 invoice.check_field_counts()?;
1091                 invoice.check_feature_bits()?;
1092                 invoice.check_signature()?;
1093
1094                 Ok(invoice)
1095         }
1096
1097         /// Returns the `Invoice`'s timestamp (should equal it's creation time)
1098         pub fn timestamp(&self) -> &SystemTime {
1099                 self.signed_invoice.raw_invoice().data.timestamp.as_time()
1100         }
1101
1102         /// Returns an iterator over all tagged fields of this Invoice.
1103         ///
1104         /// (C-not exported) As there is not yet a manual mapping for a FilterMap
1105         pub fn tagged_fields(&self)
1106                 -> FilterMap<Iter<RawTaggedField>, fn(&RawTaggedField) -> Option<&TaggedField>> {
1107                 self.signed_invoice.raw_invoice().known_tagged_fields()
1108         }
1109
1110         /// Returns the hash to which we will receive the preimage on completion of the payment
1111         pub fn payment_hash(&self) -> &sha256::Hash {
1112                 &self.signed_invoice.payment_hash().expect("checked by constructor").0
1113         }
1114
1115         /// Return the description or a hash of it for longer ones
1116         ///
1117         /// (C-not exported) because we don't yet export InvoiceDescription
1118         pub fn description(&self) -> InvoiceDescription {
1119                 if let Some(ref direct) = self.signed_invoice.description() {
1120                         return InvoiceDescription::Direct(direct);
1121                 } else if let Some(ref hash) = self.signed_invoice.description_hash() {
1122                         return InvoiceDescription::Hash(hash);
1123                 }
1124                 unreachable!("ensured by constructor");
1125         }
1126
1127         /// Get the payee's public key if one was included in the invoice
1128         pub fn payee_pub_key(&self) -> Option<&PublicKey> {
1129                 self.signed_invoice.payee_pub_key().map(|x| &x.0)
1130         }
1131
1132         /// Get the payment secret if one was included in the invoice
1133         pub fn payment_secret(&self) -> Option<&PaymentSecret> {
1134                 self.signed_invoice.payment_secret()
1135         }
1136
1137         /// Get the invoice features if they were included in the invoice
1138         pub fn features(&self) -> Option<&InvoiceFeatures> {
1139                 self.signed_invoice.features()
1140         }
1141
1142         /// Recover the payee's public key (only to be used if none was included in the invoice)
1143         pub fn recover_payee_pub_key(&self) -> PublicKey {
1144                 self.signed_invoice.recover_payee_pub_key().expect("was checked by constructor").0
1145         }
1146
1147         /// Returns the invoice's expiry time, if present, otherwise [`DEFAULT_EXPIRY_TIME`].
1148         pub fn expiry_time(&self) -> Duration {
1149                 self.signed_invoice.expiry_time()
1150                         .map(|x| x.0)
1151                         .unwrap_or(Duration::from_secs(DEFAULT_EXPIRY_TIME))
1152         }
1153
1154         /// Returns the invoice's `min_final_cltv_expiry` time, if present, otherwise
1155         /// [`DEFAULT_MIN_FINAL_CLTV_EXPIRY`].
1156         pub fn min_final_cltv_expiry(&self) -> u64 {
1157                 self.signed_invoice.min_final_cltv_expiry()
1158                         .map(|x| x.0)
1159                         .unwrap_or(DEFAULT_MIN_FINAL_CLTV_EXPIRY)
1160         }
1161
1162         /// Returns a list of all fallback addresses
1163         ///
1164         /// (C-not exported) as we don't support Vec<&NonOpaqueType>
1165         pub fn fallbacks(&self) -> Vec<&Fallback> {
1166                 self.signed_invoice.fallbacks()
1167         }
1168
1169         /// Returns a list of all routes included in the invoice
1170         pub fn private_routes(&self) -> Vec<&PrivateRoute> {
1171                 self.signed_invoice.private_routes()
1172         }
1173
1174         /// Returns a list of all routes included in the invoice as the underlying hints
1175         pub fn route_hints(&self) -> Vec<&RouteHint> {
1176                 find_all_extract!(
1177                         self.signed_invoice.known_tagged_fields(), TaggedField::PrivateRoute(ref x), x
1178                 ).map(|route| &**route).collect()
1179         }
1180
1181         /// Returns the currency for which the invoice was issued
1182         pub fn currency(&self) -> Currency {
1183                 self.signed_invoice.currency()
1184         }
1185
1186         /// Returns the amount if specified in the invoice as pico <currency>.
1187         pub fn amount_pico_btc(&self) -> Option<u64> {
1188                 self.signed_invoice.amount_pico_btc()
1189         }
1190 }
1191
1192 impl From<TaggedField> for RawTaggedField {
1193         fn from(tf: TaggedField) -> Self {
1194                 RawTaggedField::KnownSemantics(tf)
1195         }
1196 }
1197
1198 impl TaggedField {
1199         /// Numeric representation of the field's tag
1200         pub fn tag(&self) -> u5 {
1201                 let tag = match *self {
1202                         TaggedField::PaymentHash(_) => constants::TAG_PAYMENT_HASH,
1203                         TaggedField::Description(_) => constants::TAG_DESCRIPTION,
1204                         TaggedField::PayeePubKey(_) => constants::TAG_PAYEE_PUB_KEY,
1205                         TaggedField::DescriptionHash(_) => constants::TAG_DESCRIPTION_HASH,
1206                         TaggedField::ExpiryTime(_) => constants::TAG_EXPIRY_TIME,
1207                         TaggedField::MinFinalCltvExpiry(_) => constants::TAG_MIN_FINAL_CLTV_EXPIRY,
1208                         TaggedField::Fallback(_) => constants::TAG_FALLBACK,
1209                         TaggedField::PrivateRoute(_) => constants::TAG_PRIVATE_ROUTE,
1210                         TaggedField::PaymentSecret(_) => constants::TAG_PAYMENT_SECRET,
1211                         TaggedField::Features(_) => constants::TAG_FEATURES,
1212                 };
1213
1214                 u5::try_from_u8(tag).expect("all tags defined are <32")
1215         }
1216 }
1217
1218 impl Description {
1219
1220         /// Creates a new `Description` if `description` is at most 1023 __bytes__ long,
1221         /// returns `CreationError::DescriptionTooLong` otherwise
1222         ///
1223         /// Please note that single characters may use more than one byte due to UTF8 encoding.
1224         pub fn new(description: String) -> Result<Description, CreationError> {
1225                 if description.len() > 639 {
1226                         Err(CreationError::DescriptionTooLong)
1227                 } else {
1228                         Ok(Description(description))
1229                 }
1230         }
1231
1232         /// Returns the underlying description `String`
1233         pub fn into_inner(self) -> String {
1234                 self.0
1235         }
1236 }
1237
1238 impl Into<String> for Description {
1239         fn into(self) -> String {
1240                 self.into_inner()
1241         }
1242 }
1243
1244 impl Deref for Description {
1245         type Target = str;
1246
1247         fn deref(&self) -> &str {
1248                 &self.0
1249         }
1250 }
1251
1252 impl From<PublicKey> for PayeePubKey {
1253         fn from(pk: PublicKey) -> Self {
1254                 PayeePubKey(pk)
1255         }
1256 }
1257
1258 impl Deref for PayeePubKey {
1259         type Target = PublicKey;
1260
1261         fn deref(&self) -> &PublicKey {
1262                 &self.0
1263         }
1264 }
1265
1266 impl ExpiryTime {
1267         /// Construct an `ExpiryTime` from seconds. If there exists a `PositiveTimestamp` which would
1268         /// overflow on adding the `EpiryTime` to it then this function will return a
1269         /// `CreationError::ExpiryTimeOutOfBounds`.
1270         pub fn from_seconds(seconds: u64) -> Result<ExpiryTime, CreationError> {
1271                 if seconds <= MAX_EXPIRY_TIME {
1272                         Ok(ExpiryTime(Duration::from_secs(seconds)))
1273                 } else {
1274                         Err(CreationError::ExpiryTimeOutOfBounds)
1275                 }
1276         }
1277
1278         /// Construct an `ExpiryTime` from a `Duration`. If there exists a `PositiveTimestamp` which
1279         /// would overflow on adding the `EpiryTime` to it then this function will return a
1280         /// `CreationError::ExpiryTimeOutOfBounds`.
1281         pub fn from_duration(duration: Duration) -> Result<ExpiryTime, CreationError> {
1282                 if duration.as_secs() <= MAX_EXPIRY_TIME {
1283                         Ok(ExpiryTime(duration))
1284                 } else {
1285                         Err(CreationError::ExpiryTimeOutOfBounds)
1286                 }
1287         }
1288
1289         /// Returns the expiry time in seconds
1290         pub fn as_seconds(&self) -> u64 {
1291                 self.0.as_secs()
1292         }
1293
1294         /// Returns a reference to the underlying `Duration` (=expiry time)
1295         pub fn as_duration(&self) -> &Duration {
1296                 &self.0
1297         }
1298 }
1299
1300 impl PrivateRoute {
1301         /// Creates a new (partial) route from a list of hops
1302         pub fn new(hops: RouteHint) -> Result<PrivateRoute, CreationError> {
1303                 if hops.0.len() <= 12 {
1304                         Ok(PrivateRoute(hops))
1305                 } else {
1306                         Err(CreationError::RouteTooLong)
1307                 }
1308         }
1309
1310         /// Returns the underlying list of hops
1311         pub fn into_inner(self) -> RouteHint {
1312                 self.0
1313         }
1314 }
1315
1316 impl Into<RouteHint> for PrivateRoute {
1317         fn into(self) -> RouteHint {
1318                 self.into_inner()
1319         }
1320 }
1321
1322 impl Deref for PrivateRoute {
1323         type Target = RouteHint;
1324
1325         fn deref(&self) -> &RouteHint {
1326                 &self.0
1327         }
1328 }
1329
1330 impl Deref for InvoiceSignature {
1331         type Target = RecoverableSignature;
1332
1333         fn deref(&self) -> &RecoverableSignature {
1334                 &self.0
1335         }
1336 }
1337
1338 impl Deref for SignedRawInvoice {
1339         type Target = RawInvoice;
1340
1341         fn deref(&self) -> &RawInvoice {
1342                 &self.raw_invoice
1343         }
1344 }
1345
1346 /// Errors that may occur when constructing a new `RawInvoice` or `Invoice`
1347 #[derive(Eq, PartialEq, Debug, Clone)]
1348 pub enum CreationError {
1349         /// The supplied description string was longer than 639 __bytes__ (see [`Description::new(…)`](./struct.Description.html#method.new))
1350         DescriptionTooLong,
1351
1352         /// The specified route has too many hops and can't be encoded
1353         RouteTooLong,
1354
1355         /// The unix timestamp of the supplied date is <0 or can't be represented as `SystemTime`
1356         TimestampOutOfBounds,
1357
1358         /// The supplied expiry time could cause an overflow if added to a `PositiveTimestamp`
1359         ExpiryTimeOutOfBounds,
1360 }
1361
1362 impl Display for CreationError {
1363         fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
1364                 match self {
1365                         CreationError::DescriptionTooLong => f.write_str("The supplied description string was longer than 639 bytes"),
1366                         CreationError::RouteTooLong => f.write_str("The specified route has too many hops and can't be encoded"),
1367                         CreationError::TimestampOutOfBounds => f.write_str("The unix timestamp of the supplied date is <0 or can't be represented as `SystemTime`"),
1368                         CreationError::ExpiryTimeOutOfBounds => f.write_str("The supplied expiry time could cause an overflow if added to a `PositiveTimestamp`"),
1369                 }
1370         }
1371 }
1372
1373 impl std::error::Error for CreationError { }
1374
1375 /// Errors that may occur when converting a `RawInvoice` to an `Invoice`. They relate to the
1376 /// requirements sections in BOLT #11
1377 #[derive(Eq, PartialEq, Debug, Clone)]
1378 pub enum SemanticError {
1379         /// The invoice is missing the mandatory payment hash
1380         NoPaymentHash,
1381
1382         /// The invoice has multiple payment hashes which isn't allowed
1383         MultiplePaymentHashes,
1384
1385         /// No description or description hash are part of the invoice
1386         NoDescription,
1387
1388         /// The invoice contains multiple descriptions and/or description hashes which isn't allowed
1389         MultipleDescriptions,
1390
1391         /// The invoice contains multiple payment secrets
1392         MultiplePaymentSecrets,
1393
1394         /// The invoice's features are invalid
1395         InvalidFeatures,
1396
1397         /// The recovery id doesn't fit the signature/pub key
1398         InvalidRecoveryId,
1399
1400         /// The invoice's signature is invalid
1401         InvalidSignature,
1402 }
1403
1404 impl Display for SemanticError {
1405         fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
1406                 match self {
1407                         SemanticError::NoPaymentHash => f.write_str("The invoice is missing the mandatory payment hash"),
1408                         SemanticError::MultiplePaymentHashes => f.write_str("The invoice has multiple payment hashes which isn't allowed"),
1409                         SemanticError::NoDescription => f.write_str("No description or description hash are part of the invoice"),
1410                         SemanticError::MultipleDescriptions => f.write_str("The invoice contains multiple descriptions and/or description hashes which isn't allowed"),
1411                         SemanticError::MultiplePaymentSecrets => f.write_str("The invoice contains multiple payment secrets"),
1412                         SemanticError::InvalidFeatures => f.write_str("The invoice's features are invalid"),
1413                         SemanticError::InvalidRecoveryId => f.write_str("The recovery id doesn't fit the signature/pub key"),
1414                         SemanticError::InvalidSignature => f.write_str("The invoice's signature is invalid"),
1415                 }
1416         }
1417 }
1418
1419 impl std::error::Error for SemanticError { }
1420
1421 /// When signing using a fallible method either an user-supplied `SignError` or a `CreationError`
1422 /// may occur.
1423 #[derive(Eq, PartialEq, Debug, Clone)]
1424 pub enum SignOrCreationError<S = ()> {
1425         /// An error occurred during signing
1426         SignError(S),
1427
1428         /// An error occurred while building the transaction
1429         CreationError(CreationError),
1430 }
1431
1432 impl<S> Display for SignOrCreationError<S> {
1433         fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
1434                 match self {
1435                         SignOrCreationError::SignError(_) => f.write_str("An error occurred during signing"),
1436                         SignOrCreationError::CreationError(err) => err.fmt(f),
1437                 }
1438         }
1439 }
1440
1441 #[cfg(test)]
1442 mod test {
1443         use bitcoin_hashes::hex::FromHex;
1444         use bitcoin_hashes::sha256;
1445
1446         #[test]
1447         fn test_system_time_bounds_assumptions() {
1448                 ::check_platform();
1449
1450         assert_eq!(
1451             ::PositiveTimestamp::from_unix_timestamp(::SYSTEM_TIME_MAX_UNIX_TIMESTAMP + 1),
1452             Err(::CreationError::TimestampOutOfBounds)
1453         );
1454
1455         assert_eq!(
1456             ::ExpiryTime::from_seconds(::MAX_EXPIRY_TIME + 1),
1457             Err(::CreationError::ExpiryTimeOutOfBounds)
1458         );
1459         }
1460
1461         #[test]
1462         fn test_calc_invoice_hash() {
1463                 use ::{RawInvoice, RawHrp, RawDataPart, Currency, PositiveTimestamp};
1464                 use ::TaggedField::*;
1465
1466                 let invoice = RawInvoice {
1467                         hrp: RawHrp {
1468                                 currency: Currency::Bitcoin,
1469                                 raw_amount: None,
1470                                 si_prefix: None,
1471                         },
1472                         data: RawDataPart {
1473                                 timestamp: PositiveTimestamp::from_unix_timestamp(1496314658).unwrap(),
1474                                 tagged_fields: vec![
1475                                         PaymentHash(::Sha256(sha256::Hash::from_hex(
1476                                                 "0001020304050607080900010203040506070809000102030405060708090102"
1477                                         ).unwrap())).into(),
1478                                         Description(::Description::new(
1479                                                 "Please consider supporting this project".to_owned()
1480                                         ).unwrap()).into(),
1481                                 ],
1482                         },
1483                 };
1484
1485                 let expected_hash = [
1486                         0xc3, 0xd4, 0xe8, 0x3f, 0x64, 0x6f, 0xa7, 0x9a, 0x39, 0x3d, 0x75, 0x27, 0x7b, 0x1d,
1487                         0x85, 0x8d, 0xb1, 0xd1, 0xf7, 0xab, 0x71, 0x37, 0xdc, 0xb7, 0x83, 0x5d, 0xb2, 0xec,
1488                         0xd5, 0x18, 0xe1, 0xc9
1489                 ];
1490
1491                 assert_eq!(invoice.hash(), expected_hash)
1492         }
1493
1494         #[test]
1495         fn test_check_signature() {
1496                 use TaggedField::*;
1497                 use secp256k1::Secp256k1;
1498                 use secp256k1::recovery::{RecoveryId, RecoverableSignature};
1499                 use secp256k1::key::{SecretKey, PublicKey};
1500                 use {SignedRawInvoice, InvoiceSignature, RawInvoice, RawHrp, RawDataPart, Currency, Sha256,
1501                          PositiveTimestamp};
1502
1503                 let invoice = SignedRawInvoice {
1504                         raw_invoice: RawInvoice {
1505                                 hrp: RawHrp {
1506                                         currency: Currency::Bitcoin,
1507                                         raw_amount: None,
1508                                         si_prefix: None,
1509                                 },
1510                                 data: RawDataPart {
1511                                         timestamp: PositiveTimestamp::from_unix_timestamp(1496314658).unwrap(),
1512                                         tagged_fields: vec ! [
1513                                                 PaymentHash(Sha256(sha256::Hash::from_hex(
1514                                                         "0001020304050607080900010203040506070809000102030405060708090102"
1515                                                 ).unwrap())).into(),
1516                                                 Description(
1517                                                         ::Description::new(
1518                                                                 "Please consider supporting this project".to_owned()
1519                                                         ).unwrap()
1520                                                 ).into(),
1521                                         ],
1522                                 },
1523                         },
1524                         hash: [
1525                                 0xc3, 0xd4, 0xe8, 0x3f, 0x64, 0x6f, 0xa7, 0x9a, 0x39, 0x3d, 0x75, 0x27,
1526                                 0x7b, 0x1d, 0x85, 0x8d, 0xb1, 0xd1, 0xf7, 0xab, 0x71, 0x37, 0xdc, 0xb7,
1527                                 0x83, 0x5d, 0xb2, 0xec, 0xd5, 0x18, 0xe1, 0xc9
1528                         ],
1529                         signature: InvoiceSignature(RecoverableSignature::from_compact(
1530                                 & [
1531                                         0x38u8, 0xec, 0x68, 0x91, 0x34, 0x5e, 0x20, 0x41, 0x45, 0xbe, 0x8a,
1532                                         0x3a, 0x99, 0xde, 0x38, 0xe9, 0x8a, 0x39, 0xd6, 0xa5, 0x69, 0x43,
1533                                         0x4e, 0x18, 0x45, 0xc8, 0xaf, 0x72, 0x05, 0xaf, 0xcf, 0xcc, 0x7f,
1534                                         0x42, 0x5f, 0xcd, 0x14, 0x63, 0xe9, 0x3c, 0x32, 0x88, 0x1e, 0xad,
1535                                         0x0d, 0x6e, 0x35, 0x6d, 0x46, 0x7e, 0xc8, 0xc0, 0x25, 0x53, 0xf9,
1536                                         0xaa, 0xb1, 0x5e, 0x57, 0x38, 0xb1, 0x1f, 0x12, 0x7f
1537                                 ],
1538                                 RecoveryId::from_i32(0).unwrap()
1539                         ).unwrap()),
1540                 };
1541
1542                 assert!(invoice.check_signature());
1543
1544                 let private_key = SecretKey::from_slice(
1545                         &[
1546                                 0xe1, 0x26, 0xf6, 0x8f, 0x7e, 0xaf, 0xcc, 0x8b, 0x74, 0xf5, 0x4d, 0x26, 0x9f, 0xe2,
1547                                 0x06, 0xbe, 0x71, 0x50, 0x00, 0xf9, 0x4d, 0xac, 0x06, 0x7d, 0x1c, 0x04, 0xa8, 0xca,
1548                                 0x3b, 0x2d, 0xb7, 0x34
1549                         ][..]
1550                 ).unwrap();
1551                 let public_key = PublicKey::from_secret_key(&Secp256k1::new(), &private_key);
1552
1553                 assert_eq!(invoice.recover_payee_pub_key(), Ok(::PayeePubKey(public_key)));
1554
1555                 let (raw_invoice, _, _) = invoice.into_parts();
1556                 let new_signed = raw_invoice.sign::<_, ()>(|hash| {
1557                         Ok(Secp256k1::new().sign_recoverable(hash, &private_key))
1558                 }).unwrap();
1559
1560                 assert!(new_signed.check_signature());
1561         }
1562
1563         #[test]
1564         fn test_check_feature_bits() {
1565                 use TaggedField::*;
1566                 use lightning::ln::features::InvoiceFeatures;
1567                 use secp256k1::Secp256k1;
1568                 use secp256k1::key::SecretKey;
1569                 use {RawInvoice, RawHrp, RawDataPart, Currency, Sha256, PositiveTimestamp, Invoice,
1570                          SemanticError};
1571
1572                 let private_key = SecretKey::from_slice(&[42; 32]).unwrap();
1573                 let payment_secret = lightning::ln::PaymentSecret([21; 32]);
1574                 let invoice_template = RawInvoice {
1575                         hrp: RawHrp {
1576                                 currency: Currency::Bitcoin,
1577                                 raw_amount: None,
1578                                 si_prefix: None,
1579                         },
1580                         data: RawDataPart {
1581                                 timestamp: PositiveTimestamp::from_unix_timestamp(1496314658).unwrap(),
1582                                 tagged_fields: vec ! [
1583                                         PaymentHash(Sha256(sha256::Hash::from_hex(
1584                                                 "0001020304050607080900010203040506070809000102030405060708090102"
1585                                         ).unwrap())).into(),
1586                                         Description(
1587                                                 ::Description::new(
1588                                                         "Please consider supporting this project".to_owned()
1589                                                 ).unwrap()
1590                                         ).into(),
1591                                 ],
1592                         },
1593                 };
1594
1595                 // Missing features
1596                 let invoice = {
1597                         let mut invoice = invoice_template.clone();
1598                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1599                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_recoverable(hash, &private_key)))
1600                 }.unwrap();
1601                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::InvalidFeatures));
1602
1603                 // Missing feature bits
1604                 let invoice = {
1605                         let mut invoice = invoice_template.clone();
1606                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1607                         invoice.data.tagged_fields.push(Features(InvoiceFeatures::empty()).into());
1608                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_recoverable(hash, &private_key)))
1609                 }.unwrap();
1610                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::InvalidFeatures));
1611
1612                 // Including payment secret and feature bits
1613                 let invoice = {
1614                         let mut invoice = invoice_template.clone();
1615                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1616                         invoice.data.tagged_fields.push(Features(InvoiceFeatures::known()).into());
1617                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_recoverable(hash, &private_key)))
1618                 }.unwrap();
1619                 assert!(Invoice::from_signed(invoice).is_ok());
1620
1621                 // No payment secret or features
1622                 let invoice = {
1623                         let invoice = invoice_template.clone();
1624                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_recoverable(hash, &private_key)))
1625                 }.unwrap();
1626                 assert!(Invoice::from_signed(invoice).is_ok());
1627
1628                 // No payment secret or feature bits
1629                 let invoice = {
1630                         let mut invoice = invoice_template.clone();
1631                         invoice.data.tagged_fields.push(Features(InvoiceFeatures::empty()).into());
1632                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_recoverable(hash, &private_key)))
1633                 }.unwrap();
1634                 assert!(Invoice::from_signed(invoice).is_ok());
1635
1636                 // Missing payment secret
1637                 let invoice = {
1638                         let mut invoice = invoice_template.clone();
1639                         invoice.data.tagged_fields.push(Features(InvoiceFeatures::known()).into());
1640                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_recoverable(hash, &private_key)))
1641                 }.unwrap();
1642                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::InvalidFeatures));
1643
1644                 // Multiple payment secrets
1645                 let invoice = {
1646                         let mut invoice = invoice_template.clone();
1647                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1648                         invoice.data.tagged_fields.push(PaymentSecret(payment_secret).into());
1649                         invoice.sign::<_, ()>(|hash| Ok(Secp256k1::new().sign_recoverable(hash, &private_key)))
1650                 }.unwrap();
1651                 assert_eq!(Invoice::from_signed(invoice), Err(SemanticError::MultiplePaymentSecrets));
1652         }
1653
1654         #[test]
1655         fn test_builder_amount() {
1656                 use ::*;
1657
1658                 let builder = InvoiceBuilder::new(Currency::Bitcoin)
1659                         .description("Test".into())
1660                         .payment_hash(sha256::Hash::from_slice(&[0;32][..]).unwrap())
1661                         .current_timestamp();
1662
1663                 let invoice = builder.clone()
1664                         .amount_pico_btc(15000)
1665                         .build_raw()
1666                         .unwrap();
1667
1668                 assert_eq!(invoice.hrp.si_prefix, Some(SiPrefix::Nano));
1669                 assert_eq!(invoice.hrp.raw_amount, Some(15));
1670
1671
1672                 let invoice = builder.clone()
1673                         .amount_pico_btc(1500)
1674                         .build_raw()
1675                         .unwrap();
1676
1677                 assert_eq!(invoice.hrp.si_prefix, Some(SiPrefix::Pico));
1678                 assert_eq!(invoice.hrp.raw_amount, Some(1500));
1679         }
1680
1681         #[test]
1682         fn test_builder_fail() {
1683                 use ::*;
1684                 use lightning::routing::router::RouteHintHop;
1685                 use std::iter::FromIterator;
1686                 use secp256k1::key::PublicKey;
1687
1688                 let builder = InvoiceBuilder::new(Currency::Bitcoin)
1689                         .payment_hash(sha256::Hash::from_slice(&[0;32][..]).unwrap())
1690                         .current_timestamp()
1691                         .min_final_cltv_expiry(144);
1692
1693                 let too_long_string = String::from_iter(
1694                         (0..1024).map(|_| '?')
1695                 );
1696
1697                 let long_desc_res = builder.clone()
1698                         .description(too_long_string)
1699                         .build_raw();
1700                 assert_eq!(long_desc_res, Err(CreationError::DescriptionTooLong));
1701
1702                 let route_hop = RouteHintHop {
1703                         src_node_id: PublicKey::from_slice(
1704                                         &[
1705                                                 0x03, 0x9e, 0x03, 0xa9, 0x01, 0xb8, 0x55, 0x34, 0xff, 0x1e, 0x92, 0xc4,
1706                                                 0x3c, 0x74, 0x43, 0x1f, 0x7c, 0xe7, 0x20, 0x46, 0x06, 0x0f, 0xcf, 0x7a,
1707                                                 0x95, 0xc3, 0x7e, 0x14, 0x8f, 0x78, 0xc7, 0x72, 0x55
1708                                         ][..]
1709                                 ).unwrap(),
1710                         short_channel_id: 0,
1711                         fees: RoutingFees {
1712                                 base_msat: 0,
1713                                 proportional_millionths: 0,
1714                         },
1715                         cltv_expiry_delta: 0,
1716                         htlc_minimum_msat: None,
1717                         htlc_maximum_msat: None,
1718                 };
1719                 let too_long_route = RouteHint(vec![route_hop; 13]);
1720                 let long_route_res = builder.clone()
1721                         .description("Test".into())
1722                         .private_route(too_long_route)
1723                         .build_raw();
1724                 assert_eq!(long_route_res, Err(CreationError::RouteTooLong));
1725
1726                 let sign_error_res = builder.clone()
1727                         .description("Test".into())
1728                         .try_build_signed(|_| {
1729                                 Err("ImaginaryError")
1730                         });
1731                 assert_eq!(sign_error_res, Err(SignOrCreationError::SignError("ImaginaryError")));
1732         }
1733
1734         #[test]
1735         fn test_builder_ok() {
1736                 use ::*;
1737                 use lightning::routing::router::RouteHintHop;
1738                 use secp256k1::Secp256k1;
1739                 use secp256k1::key::{SecretKey, PublicKey};
1740                 use std::time::{UNIX_EPOCH, Duration};
1741
1742                 let secp_ctx = Secp256k1::new();
1743
1744                 let private_key = SecretKey::from_slice(
1745                         &[
1746                                 0xe1, 0x26, 0xf6, 0x8f, 0x7e, 0xaf, 0xcc, 0x8b, 0x74, 0xf5, 0x4d, 0x26, 0x9f, 0xe2,
1747                                 0x06, 0xbe, 0x71, 0x50, 0x00, 0xf9, 0x4d, 0xac, 0x06, 0x7d, 0x1c, 0x04, 0xa8, 0xca,
1748                                 0x3b, 0x2d, 0xb7, 0x34
1749                         ][..]
1750                 ).unwrap();
1751                 let public_key = PublicKey::from_secret_key(&secp_ctx, &private_key);
1752
1753                 let route_1 = RouteHint(vec![
1754                         RouteHintHop {
1755                                 src_node_id: public_key.clone(),
1756                                 short_channel_id: de::parse_int_be(&[123; 8], 256).expect("short chan ID slice too big?"),
1757                                 fees: RoutingFees {
1758                                         base_msat: 2,
1759                                         proportional_millionths: 1,
1760                                 },
1761                                 cltv_expiry_delta: 145,
1762                                 htlc_minimum_msat: None,
1763                                 htlc_maximum_msat: None,
1764                         },
1765                         RouteHintHop {
1766                                 src_node_id: public_key.clone(),
1767                                 short_channel_id: de::parse_int_be(&[42; 8], 256).expect("short chan ID slice too big?"),
1768                                 fees: RoutingFees {
1769                                         base_msat: 3,
1770                                         proportional_millionths: 2,
1771                                 },
1772                                 cltv_expiry_delta: 146,
1773                                 htlc_minimum_msat: None,
1774                                 htlc_maximum_msat: None,
1775                         }
1776                 ]);
1777
1778                 let route_2 = RouteHint(vec![
1779                         RouteHintHop {
1780                                 src_node_id: public_key.clone(),
1781                                 short_channel_id: 0,
1782                                 fees: RoutingFees {
1783                                         base_msat: 4,
1784                                         proportional_millionths: 3,
1785                                 },
1786                                 cltv_expiry_delta: 147,
1787                                 htlc_minimum_msat: None,
1788                                 htlc_maximum_msat: None,
1789                         },
1790                         RouteHintHop {
1791                                 src_node_id: public_key.clone(),
1792                                 short_channel_id: de::parse_int_be(&[1; 8], 256).expect("short chan ID slice too big?"),
1793                                 fees: RoutingFees {
1794                                         base_msat: 5,
1795                                         proportional_millionths: 4,
1796                                 },
1797                                 cltv_expiry_delta: 148,
1798                                 htlc_minimum_msat: None,
1799                                 htlc_maximum_msat: None,
1800                         }
1801                 ]);
1802
1803                 let builder = InvoiceBuilder::new(Currency::BitcoinTestnet)
1804                         .amount_pico_btc(123)
1805                         .timestamp(UNIX_EPOCH + Duration::from_secs(1234567))
1806                         .payee_pub_key(public_key.clone())
1807                         .expiry_time(Duration::from_secs(54321))
1808                         .min_final_cltv_expiry(144)
1809                         .fallback(Fallback::PubKeyHash([0;20]))
1810                         .private_route(route_1.clone())
1811                         .private_route(route_2.clone())
1812                         .description_hash(sha256::Hash::from_slice(&[3;32][..]).unwrap())
1813                         .payment_hash(sha256::Hash::from_slice(&[21;32][..]).unwrap())
1814                         .payment_secret(PaymentSecret([42; 32]))
1815                         .basic_mpp();
1816
1817                 let invoice = builder.clone().build_signed(|hash| {
1818                         secp_ctx.sign_recoverable(hash, &private_key)
1819                 }).unwrap();
1820
1821                 assert!(invoice.check_signature().is_ok());
1822                 assert_eq!(invoice.tagged_fields().count(), 10);
1823
1824                 assert_eq!(invoice.amount_pico_btc(), Some(123));
1825                 assert_eq!(invoice.currency(), Currency::BitcoinTestnet);
1826                 assert_eq!(
1827                         invoice.timestamp().duration_since(UNIX_EPOCH).unwrap().as_secs(),
1828                         1234567
1829                 );
1830                 assert_eq!(invoice.payee_pub_key(), Some(&public_key));
1831                 assert_eq!(invoice.expiry_time(), Duration::from_secs(54321));
1832                 assert_eq!(invoice.min_final_cltv_expiry(), 144);
1833                 assert_eq!(invoice.fallbacks(), vec![&Fallback::PubKeyHash([0;20])]);
1834                 assert_eq!(invoice.private_routes(), vec![&PrivateRoute(route_1), &PrivateRoute(route_2)]);
1835                 assert_eq!(
1836                         invoice.description(),
1837                         InvoiceDescription::Hash(&Sha256(sha256::Hash::from_slice(&[3;32][..]).unwrap()))
1838                 );
1839                 assert_eq!(invoice.payment_hash(), &sha256::Hash::from_slice(&[21;32][..]).unwrap());
1840                 assert_eq!(invoice.payment_secret(), Some(&PaymentSecret([42; 32])));
1841                 assert_eq!(invoice.features(), Some(&InvoiceFeatures::known()));
1842
1843                 let raw_invoice = builder.build_raw().unwrap();
1844                 assert_eq!(raw_invoice, *invoice.into_signed_raw().raw_invoice())
1845         }
1846
1847         #[test]
1848         fn test_default_values() {
1849                 use ::*;
1850                 use secp256k1::Secp256k1;
1851                 use secp256k1::key::SecretKey;
1852
1853                 let signed_invoice = InvoiceBuilder::new(Currency::Bitcoin)
1854                         .description("Test".into())
1855                         .payment_hash(sha256::Hash::from_slice(&[0;32][..]).unwrap())
1856                         .current_timestamp()
1857                         .build_raw()
1858                         .unwrap()
1859                         .sign::<_, ()>(|hash| {
1860                                 let privkey = SecretKey::from_slice(&[41; 32]).unwrap();
1861                                 let secp_ctx = Secp256k1::new();
1862                                 Ok(secp_ctx.sign_recoverable(hash, &privkey))
1863                         })
1864                         .unwrap();
1865                 let invoice = Invoice::from_signed(signed_invoice).unwrap();
1866
1867                 assert_eq!(invoice.min_final_cltv_expiry(), DEFAULT_MIN_FINAL_CLTV_EXPIRY);
1868                 assert_eq!(invoice.expiry_time(), Duration::from_secs(DEFAULT_EXPIRY_TIME));
1869         }
1870 }