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

   1 use std::fmt;
   2 use std::fmt::{Display, Formatter};
   3 use bech32::{ToBase32, u5, WriteBase32, Base32Len};
   4
   5 use super::{Invoice, Sha256, TaggedField, ExpiryTime, MinFinalCltvExpiry, Fallback, PayeePubKey, InvoiceSignature, PositiveTimestamp,
   6         RouteHint, Description, RawTaggedField, Currency, RawHrp, SiPrefix, constants, SignedRawInvoice, RawDataPart};
   7
   8 /// Converts a stream of bytes written to it to base32. On finalization the according padding will
   9 /// be applied. That means the results of writing two data blocks with one or two `BytesToBase32`
  10 /// converters will differ.
  11 struct BytesToBase32<'a, W: WriteBase32 + 'a> {
  12         /// Target for writing the resulting `u5`s resulting from the written bytes
  13         writer: &'a mut W,
  14         /// Holds all unwritten bits left over from last round. The bits are stored beginning from
  15         /// the most significant bit. E.g. if buffer_bits=3, then the byte with bits a, b and c will
  16         /// look as follows: [a, b, c, 0, 0, 0, 0, 0]
  17         buffer: u8,
  18         /// Amount of bits left over from last round, stored in buffer.
  19         buffer_bits: u8,
  20 }
  21
  22 impl<'a, W: WriteBase32> BytesToBase32<'a, W> {
  23         /// Create a new bytes-to-base32 converter with `writer` as  a sink for the resulting base32
  24         /// data.
  25         pub fn new(writer: &'a mut W) -> BytesToBase32<'a, W> {
  26                 BytesToBase32 {
  27                         writer,
  28                         buffer: 0,
  29                         buffer_bits: 0,
  30                 }
  31         }
  32
  33         /// Add more bytes to the current conversion unit
  34         pub fn append(&mut self, bytes: &[u8]) -> Result<(), W::Err> {
  35                 for b in bytes {
  36                         self.append_u8(*b)?;
  37                 }
  38                 Ok(())
  39         }
  40
  41         pub fn append_u8(&mut self, byte: u8) -> Result<(), W::Err> {
  42                 // Write first u5 if we have to write two u5s this round. That only happens if the
  43                 // buffer holds too many bits, so we don't have to combine buffer bits with new bits
  44                 // from this rounds byte.
  45                 if self.buffer_bits >= 5 {
  46                         self.writer.write_u5(
  47                                 u5::try_from_u8((self.buffer & 0b11111000) >> 3 ).expect("<32")
  48                         )?;
  49                         self.buffer = self.buffer << 5;
  50                         self.buffer_bits -= 5;
  51                 }
  52
  53                 // Combine all bits from buffer with enough bits from this rounds byte so that they fill
  54                 // a u5. Save reamining bits from byte to buffer.
  55                 let from_buffer = self.buffer >> 3;
  56                 let from_byte = byte >> (3 + self.buffer_bits); // buffer_bits <= 4
  57
  58                 self.writer.write_u5(u5::try_from_u8(from_buffer | from_byte).expect("<32"))?;
  59                 self.buffer = byte << (5 - self.buffer_bits);
  60                 self.buffer_bits = 3 + self.buffer_bits;
  61
  62                 Ok(())
  63         }
  64
  65         pub fn finalize(mut self) ->  Result<(), W::Err> {
  66                 self.inner_finalize()?;
  67                 std::mem::forget(self);
  68                 Ok(())
  69         }
  70
  71         fn inner_finalize(&mut self) -> Result<(), W::Err>{
  72                 // There can be at most two u5s left in the buffer after processing all bytes, write them.
  73                 if self.buffer_bits >= 5 {
  74                         self.writer.write_u5(
  75                                 u5::try_from_u8((self.buffer & 0b11111000) >> 3).expect("<32")
  76                         )?;
  77                         self.buffer = self.buffer << 5;
  78                         self.buffer_bits -= 5;
  79                 }
  80
  81                 if self.buffer_bits != 0 {
  82                         self.writer.write_u5(u5::try_from_u8(self.buffer >> 3).expect("<32"))?;
  83                 }
  84
  85                 Ok(())
  86         }
  87 }
  88
  89 impl<'a, W: WriteBase32> Drop for BytesToBase32<'a, W> {
  90         fn drop(&mut self) {
  91                 self.inner_finalize()
  92                         .expect("Unhandled error when finalizing conversion on drop. User finalize to handle.")
  93         }
  94 }
  95
  96 /// Calculates the base32 encoded size of a byte slice
  97 fn bytes_size_to_base32_size(byte_size: usize) -> usize {
  98         let bits = byte_size * 8;
  99         if bits % 5 == 0 {
 100                 // without padding bits
 101                 bits / 5
 102         } else {
 103                 // with padding bits
 104                 bits / 5 + 1
 105         }
 106 }
 107
 108 impl Display for Invoice {
 109         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 110                 self.signed_invoice.fmt(f)
 111         }
 112 }
 113
 114 impl Display for SignedRawInvoice {
 115         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 116                 let hrp = self.raw_invoice.hrp.to_string();
 117                 let mut data  = self.raw_invoice.data.to_base32();
 118                 data.extend_from_slice(&self.signature.to_base32());
 119
 120                 bech32::encode_to_fmt(f, &hrp, data).expect("HRP is valid")?;
 121
 122                 Ok(())
 123         }
 124 }
 125
 126 impl Display for RawHrp {
 127         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 128                 let amount = match self.raw_amount {
 129                         Some(ref amt) => amt.to_string(),
 130                         None => String::new(),
 131                 };
 132
 133                 let si_prefix = match self.si_prefix {
 134                         Some(ref si) => si.to_string(),
 135                         None => String::new(),
 136                 };
 137
 138                 write!(
 139                         f,
 140                         "ln{}{}{}",
 141                         self.currency,
 142                         amount,
 143                         si_prefix
 144                 )
 145         }
 146 }
 147
 148 impl Display for Currency {
 149         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 150                 let currency_code = match *self {
 151                         Currency::Bitcoin => "bc",
 152                         Currency::BitcoinTestnet => "tb",
 153                         Currency::Regtest => "bcrt",
 154                         Currency::Simnet => "sb",
 155                 };
 156                 write!(f, "{}", currency_code)
 157         }
 158 }
 159
 160 impl Display for SiPrefix {
 161         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 162                 write!(f, "{}",
 163                         match *self {
 164                                 SiPrefix::Milli => "m",
 165                                 SiPrefix::Micro => "u",
 166                                 SiPrefix::Nano => "n",
 167                                 SiPrefix::Pico => "p",
 168                         }
 169                 )
 170         }
 171 }
 172
 173 fn encode_int_be_base32(int: u64) -> Vec<u5> {
 174         let base = 32u64;
 175
 176         let mut out_vec = Vec::<u5>::new();
 177
 178         let mut rem_int = int;
 179         while rem_int != 0 {
 180                 out_vec.push(u5::try_from_u8((rem_int % base) as u8).expect("always <32"));
 181                 rem_int /= base;
 182         }
 183
 184         out_vec.reverse();
 185         out_vec
 186 }
 187
 188 fn encoded_int_be_base32_size(int: u64) -> usize {
 189         for pos in (0..13).rev() {
 190                 if int & (0x1f << (5 * pos)) != 0 {
 191                         return (pos + 1) as usize;
 192                 }
 193         }
 194         0usize
 195 }
 196
 197 fn encode_int_be_base256<T: Into<u64>>(int: T) -> Vec<u8> {
 198         let base = 256u64;
 199
 200         let mut out_vec = Vec::<u8>::new();
 201
 202         let mut rem_int: u64 = int.into();
 203         while rem_int != 0 {
 204                 out_vec.push((rem_int % base) as u8);
 205                 rem_int /= base;
 206         }
 207
 208         out_vec.reverse();
 209         out_vec
 210 }
 211
 212 /// Appends the default value of `T` to the front of the `in_vec` till it reaches the length
 213 /// `target_length`. If `in_vec` already is too lang `None` is returned.
 214 fn try_stretch<T>(mut in_vec: Vec<T>, target_len: usize) -> Option<Vec<T>>
 215         where T: Default + Copy
 216 {
 217         if in_vec.len() > target_len {
 218                 None
 219         } else if in_vec.len() == target_len {
 220                 Some(in_vec)
 221         } else {
 222                 let mut out_vec = Vec::<T>::with_capacity(target_len);
 223                 out_vec.append(&mut vec![T::default(); target_len - in_vec.len()]);
 224                 out_vec.append(&mut in_vec);
 225                 Some(out_vec)
 226         }
 227 }
 228
 229 impl ToBase32 for RawDataPart {
 230         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 231                 // encode timestamp
 232                 self.timestamp.write_base32(writer)?;
 233
 234                 // encode tagged fields
 235                 for tagged_field in self.tagged_fields.iter() {
 236                         tagged_field.write_base32(writer)?;
 237                 }
 238
 239                 Ok(())
 240         }
 241 }
 242
 243 impl ToBase32 for PositiveTimestamp {
 244         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 245                 // FIXME: use writer for int encoding
 246                 writer.write(
 247                         &try_stretch(encode_int_be_base32(self.as_unix_timestamp()), 7)
 248                                 .expect("Can't be longer due than 7 u5s due to timestamp bounds")
 249                 )
 250         }
 251 }
 252
 253 impl ToBase32 for RawTaggedField {
 254         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 255                 match *self {
 256                         RawTaggedField::UnknownSemantics(ref content) => {
 257                                 writer.write(content)
 258                         },
 259                         RawTaggedField::KnownSemantics(ref tagged_field) => {
 260                                 tagged_field.write_base32(writer)
 261                         }
 262                 }
 263         }
 264 }
 265
 266 impl ToBase32 for Sha256 {
 267         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 268                 (&self.0[..]).write_base32(writer)
 269         }
 270 }
 271 impl Base32Len for Sha256 {
 272         fn base32_len(&self) -> usize {
 273                 (&self.0[..]).base32_len()
 274         }
 275 }
 276
 277 impl ToBase32 for Description {
 278         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 279                 self.as_bytes().write_base32(writer)
 280         }
 281 }
 282
 283 impl Base32Len for Description {
 284         fn base32_len(&self) -> usize {
 285                 self.0.as_bytes().base32_len()
 286         }
 287 }
 288
 289 impl ToBase32 for PayeePubKey {
 290         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 291                 (&self.serialize()[..]).write_base32(writer)
 292         }
 293 }
 294
 295 impl Base32Len for PayeePubKey {
 296         fn base32_len(&self) -> usize {
 297                 bytes_size_to_base32_size(secp256k1::constants::PUBLIC_KEY_SIZE)
 298         }
 299 }
 300
 301 impl ToBase32 for ExpiryTime {
 302         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 303                 writer.write(&encode_int_be_base32(self.as_seconds()))
 304         }
 305 }
 306
 307 impl Base32Len for ExpiryTime {
 308         fn base32_len(&self) -> usize {
 309                 encoded_int_be_base32_size(self.0.as_secs())
 310         }
 311 }
 312
 313 impl ToBase32 for MinFinalCltvExpiry {
 314         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 315                 writer.write(&encode_int_be_base32(self.0))
 316         }
 317 }
 318
 319 impl Base32Len for MinFinalCltvExpiry {
 320         fn base32_len(&self) -> usize {
 321                 encoded_int_be_base32_size(self.0)
 322         }
 323 }
 324
 325 impl ToBase32 for Fallback {
 326         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 327                 match *self {
 328                         Fallback::SegWitProgram {version: v, program: ref p} => {
 329                                 writer.write_u5(v)?;
 330                                 p.write_base32(writer)
 331                         },
 332                         Fallback::PubKeyHash(ref hash) => {
 333                                 writer.write_u5(u5::try_from_u8(17).expect("17 < 32"))?;
 334                                 (&hash[..]).write_base32(writer)
 335                         },
 336                         Fallback::ScriptHash(ref hash) => {
 337                                 writer.write_u5(u5::try_from_u8(18).expect("18 < 32"))?;
 338                                 (&hash[..]).write_base32(writer)
 339                         }
 340                 }
 341         }
 342 }
 343
 344 impl Base32Len for Fallback {
 345         fn base32_len(&self) -> usize {
 346                 match *self {
 347                         Fallback::SegWitProgram {program: ref p, ..} => {
 348                                 bytes_size_to_base32_size(p.len()) + 1
 349                         },
 350                         Fallback::PubKeyHash(_) | Fallback::ScriptHash(_) => {
 351                                 33
 352                         },
 353                 }
 354         }
 355 }
 356
 357 impl ToBase32 for RouteHint {
 358         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 359                 let mut converter = BytesToBase32::new(writer);
 360
 361                 for hop in self.iter() {
 362                         converter.append(&hop.src_node_id.serialize()[..])?;
 363                         let short_channel_id = try_stretch(
 364                                 encode_int_be_base256(hop.short_channel_id),
 365                                 8
 366                         ).expect("sizeof(u64) == 8");
 367                         converter.append(&short_channel_id)?;
 368
 369                         let fee_base_msat = try_stretch(
 370                                 encode_int_be_base256(hop.fees.base_msat),
 371                                 4
 372                         ).expect("sizeof(u32) == 4");
 373                         converter.append(&fee_base_msat)?;
 374
 375                         let fee_proportional_millionths = try_stretch(
 376                                 encode_int_be_base256(hop.fees.proportional_millionths),
 377                                 4
 378                         ).expect("sizeof(u32) == 4");
 379                         converter.append(&fee_proportional_millionths)?;
 380
 381                         let cltv_expiry_delta = try_stretch(
 382                                 encode_int_be_base256(hop.cltv_expiry_delta),
 383                                 2
 384                         ).expect("sizeof(u16) == 2");
 385                         converter.append(&cltv_expiry_delta)?;
 386                 }
 387
 388                 converter.finalize()?;
 389                 Ok(())
 390         }
 391 }
 392
 393 impl Base32Len for RouteHint {
 394         fn base32_len(&self) -> usize {
 395                 bytes_size_to_base32_size(self.0.len() * 51)
 396         }
 397 }
 398
 399 impl ToBase32 for TaggedField {
 400         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 401                 /// Writes a tagged field: tag, length and data. `tag` should be in `0..32` otherwise the
 402                 /// function will panic.
 403                 fn write_tagged_field<W, P>(writer: &mut W, tag: u8, payload: &P) -> Result<(), W::Err>
 404                         where W: WriteBase32,
 405                                   P: ToBase32 + Base32Len,
 406                 {
 407                         let len = payload.base32_len();
 408                         assert!(len < 1024, "Every tagged field data can be at most 1023 bytes long.");
 409
 410                         writer.write_u5(u5::try_from_u8(tag).expect("invalid tag, not in 0..32"))?;
 411                         writer.write(&try_stretch(
 412                                 encode_int_be_base32(len as u64),
 413                                 2
 414                         ).expect("Can't be longer than 2, see assert above."))?;
 415                         payload.write_base32(writer)
 416                 }
 417
 418                 match *self {
 419                         TaggedField::PaymentHash(ref hash) => {
 420                                 write_tagged_field(writer, constants::TAG_PAYMENT_HASH, hash)
 421                         },
 422                         TaggedField::Description(ref description) => {
 423                                 write_tagged_field(writer, constants::TAG_DESCRIPTION, description)
 424                         },
 425                         TaggedField::PayeePubKey(ref pub_key) => {
 426                                 write_tagged_field(writer, constants::TAG_PAYEE_PUB_KEY, pub_key)
 427                         },
 428                         TaggedField::DescriptionHash(ref hash) => {
 429                                 write_tagged_field(writer, constants::TAG_DESCRIPTION_HASH, hash)
 430                         },
 431                         TaggedField::ExpiryTime(ref duration) => {
 432                                 write_tagged_field(writer, constants::TAG_EXPIRY_TIME, duration)
 433                         },
 434                         TaggedField::MinFinalCltvExpiry(ref expiry) => {
 435                                 write_tagged_field(writer, constants::TAG_MIN_FINAL_CLTV_EXPIRY, expiry)
 436                         },
 437                         TaggedField::Fallback(ref fallback_address) => {
 438                                 write_tagged_field(writer, constants::TAG_FALLBACK, fallback_address)
 439                         },
 440                         TaggedField::Route(ref route_hops) => {
 441                                 write_tagged_field(writer, constants::TAG_ROUTE, route_hops)
 442                         },
 443                         TaggedField::PaymentSecret(ref payment_secret) => {
 444                                   write_tagged_field(writer, constants::TAG_PAYMENT_SECRET, payment_secret)
 445                         },
 446                         TaggedField::Features(ref features) => {
 447                                 write_tagged_field(writer, constants::TAG_FEATURES, features)
 448                         },
 449                 }
 450         }
 451 }
 452
 453 impl ToBase32 for InvoiceSignature {
 454         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 455                 let mut converter = BytesToBase32::new(writer);
 456                 let (recovery_id, signature) = self.0.serialize_compact();
 457                 converter.append(&signature[..])?;
 458                 converter.append_u8(recovery_id.to_i32() as u8)?;
 459                 converter.finalize()
 460         }
 461 }
 462
 463 #[cfg(test)]
 464 mod test {
 465         use bech32::CheckBase32;
 466
 467         #[test]
 468         fn test_currency_code() {
 469                 use Currency;
 470
 471                 assert_eq!("bc", Currency::Bitcoin.to_string());
 472                 assert_eq!("tb", Currency::BitcoinTestnet.to_string());
 473                 assert_eq!("bcrt", Currency::Regtest.to_string());
 474                 assert_eq!("sb", Currency::Simnet.to_string());
 475         }
 476
 477         #[test]
 478         fn test_raw_hrp() {
 479                 use ::{Currency, RawHrp, SiPrefix};
 480
 481                 let hrp = RawHrp {
 482                         currency: Currency::Bitcoin,
 483                         raw_amount: Some(100),
 484                         si_prefix: Some(SiPrefix::Micro),
 485                 };
 486
 487                 assert_eq!(hrp.to_string(), "lnbc100u");
 488         }
 489
 490         #[test]
 491         fn test_encode_int_be_base32() {
 492                 use ser::encode_int_be_base32;
 493
 494                 let input: u64 = 33764;
 495                 let expected_out = CheckBase32::check_base32(&[1, 0, 31, 4]).unwrap();
 496
 497                 assert_eq!(expected_out, encode_int_be_base32(input));
 498         }
 499
 500         #[test]
 501         fn test_encode_int_be_base256() {
 502                 use ser::encode_int_be_base256;
 503
 504                 let input: u64 = 16842530;
 505                 let expected_out = vec![1, 0, 255, 34];
 506
 507                 assert_eq!(expected_out, encode_int_be_base256(input));
 508         }
 509 }