_ 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 /// (C-not exported)
 127 impl Display for RawHrp {
 128         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 129                 let amount = match self.raw_amount {
 130                         Some(ref amt) => amt.to_string(),
 131                         None => String::new(),
 132                 };
 133
 134                 let si_prefix = match self.si_prefix {
 135                         Some(ref si) => si.to_string(),
 136                         None => String::new(),
 137                 };
 138
 139                 write!(
 140                         f,
 141                         "ln{}{}{}",
 142                         self.currency,
 143                         amount,
 144                         si_prefix
 145                 )
 146         }
 147 }
 148
 149 impl Display for Currency {
 150         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 151                 let currency_code = match *self {
 152                         Currency::Bitcoin => "bc",
 153                         Currency::BitcoinTestnet => "tb",
 154                         Currency::Regtest => "bcrt",
 155                         Currency::Simnet => "sb",
 156                 };
 157                 write!(f, "{}", currency_code)
 158         }
 159 }
 160
 161 impl Display for SiPrefix {
 162         fn fmt(&self, f: &mut Formatter) -> Result<(), fmt::Error> {
 163                 write!(f, "{}",
 164                         match *self {
 165                                 SiPrefix::Milli => "m",
 166                                 SiPrefix::Micro => "u",
 167                                 SiPrefix::Nano => "n",
 168                                 SiPrefix::Pico => "p",
 169                         }
 170                 )
 171         }
 172 }
 173
 174 fn encode_int_be_base32(int: u64) -> Vec<u5> {
 175         let base = 32u64;
 176
 177         let mut out_vec = Vec::<u5>::new();
 178
 179         let mut rem_int = int;
 180         while rem_int != 0 {
 181                 out_vec.push(u5::try_from_u8((rem_int % base) as u8).expect("always <32"));
 182                 rem_int /= base;
 183         }
 184
 185         out_vec.reverse();
 186         out_vec
 187 }
 188
 189 fn encoded_int_be_base32_size(int: u64) -> usize {
 190         for pos in (0..13).rev() {
 191                 if int & (0x1f << (5 * pos)) != 0 {
 192                         return (pos + 1) as usize;
 193                 }
 194         }
 195         0usize
 196 }
 197
 198 fn encode_int_be_base256<T: Into<u64>>(int: T) -> Vec<u8> {
 199         let base = 256u64;
 200
 201         let mut out_vec = Vec::<u8>::new();
 202
 203         let mut rem_int: u64 = int.into();
 204         while rem_int != 0 {
 205                 out_vec.push((rem_int % base) as u8);
 206                 rem_int /= base;
 207         }
 208
 209         out_vec.reverse();
 210         out_vec
 211 }
 212
 213 /// Appends the default value of `T` to the front of the `in_vec` till it reaches the length
 214 /// `target_length`. If `in_vec` already is too lang `None` is returned.
 215 fn try_stretch<T>(mut in_vec: Vec<T>, target_len: usize) -> Option<Vec<T>>
 216         where T: Default + Copy
 217 {
 218         if in_vec.len() > target_len {
 219                 None
 220         } else if in_vec.len() == target_len {
 221                 Some(in_vec)
 222         } else {
 223                 let mut out_vec = Vec::<T>::with_capacity(target_len);
 224                 out_vec.append(&mut vec![T::default(); target_len - in_vec.len()]);
 225                 out_vec.append(&mut in_vec);
 226                 Some(out_vec)
 227         }
 228 }
 229
 230 impl ToBase32 for RawDataPart {
 231         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 232                 // encode timestamp
 233                 self.timestamp.write_base32(writer)?;
 234
 235                 // encode tagged fields
 236                 for tagged_field in self.tagged_fields.iter() {
 237                         tagged_field.write_base32(writer)?;
 238                 }
 239
 240                 Ok(())
 241         }
 242 }
 243
 244 impl ToBase32 for PositiveTimestamp {
 245         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 246                 // FIXME: use writer for int encoding
 247                 writer.write(
 248                         &try_stretch(encode_int_be_base32(self.as_unix_timestamp()), 7)
 249                                 .expect("Can't be longer due than 7 u5s due to timestamp bounds")
 250                 )
 251         }
 252 }
 253
 254 impl ToBase32 for RawTaggedField {
 255         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 256                 match *self {
 257                         RawTaggedField::UnknownSemantics(ref content) => {
 258                                 writer.write(content)
 259                         },
 260                         RawTaggedField::KnownSemantics(ref tagged_field) => {
 261                                 tagged_field.write_base32(writer)
 262                         }
 263                 }
 264         }
 265 }
 266
 267 impl ToBase32 for Sha256 {
 268         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 269                 (&self.0[..]).write_base32(writer)
 270         }
 271 }
 272 impl Base32Len for Sha256 {
 273         fn base32_len(&self) -> usize {
 274                 (&self.0[..]).base32_len()
 275         }
 276 }
 277
 278 impl ToBase32 for Description {
 279         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 280                 self.as_bytes().write_base32(writer)
 281         }
 282 }
 283
 284 impl Base32Len for Description {
 285         fn base32_len(&self) -> usize {
 286                 self.0.as_bytes().base32_len()
 287         }
 288 }
 289
 290 impl ToBase32 for PayeePubKey {
 291         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 292                 (&self.serialize()[..]).write_base32(writer)
 293         }
 294 }
 295
 296 impl Base32Len for PayeePubKey {
 297         fn base32_len(&self) -> usize {
 298                 bytes_size_to_base32_size(secp256k1::constants::PUBLIC_KEY_SIZE)
 299         }
 300 }
 301
 302 impl ToBase32 for ExpiryTime {
 303         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 304                 writer.write(&encode_int_be_base32(self.as_seconds()))
 305         }
 306 }
 307
 308 impl Base32Len for ExpiryTime {
 309         fn base32_len(&self) -> usize {
 310                 encoded_int_be_base32_size(self.0.as_secs())
 311         }
 312 }
 313
 314 impl ToBase32 for MinFinalCltvExpiry {
 315         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 316                 writer.write(&encode_int_be_base32(self.0))
 317         }
 318 }
 319
 320 impl Base32Len for MinFinalCltvExpiry {
 321         fn base32_len(&self) -> usize {
 322                 encoded_int_be_base32_size(self.0)
 323         }
 324 }
 325
 326 impl ToBase32 for Fallback {
 327         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 328                 match *self {
 329                         Fallback::SegWitProgram {version: v, program: ref p} => {
 330                                 writer.write_u5(v)?;
 331                                 p.write_base32(writer)
 332                         },
 333                         Fallback::PubKeyHash(ref hash) => {
 334                                 writer.write_u5(u5::try_from_u8(17).expect("17 < 32"))?;
 335                                 (&hash[..]).write_base32(writer)
 336                         },
 337                         Fallback::ScriptHash(ref hash) => {
 338                                 writer.write_u5(u5::try_from_u8(18).expect("18 < 32"))?;
 339                                 (&hash[..]).write_base32(writer)
 340                         }
 341                 }
 342         }
 343 }
 344
 345 impl Base32Len for Fallback {
 346         fn base32_len(&self) -> usize {
 347                 match *self {
 348                         Fallback::SegWitProgram {program: ref p, ..} => {
 349                                 bytes_size_to_base32_size(p.len()) + 1
 350                         },
 351                         Fallback::PubKeyHash(_) | Fallback::ScriptHash(_) => {
 352                                 33
 353                         },
 354                 }
 355         }
 356 }
 357
 358 impl ToBase32 for RouteHint {
 359         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 360                 let mut converter = BytesToBase32::new(writer);
 361
 362                 for hop in self.iter() {
 363                         converter.append(&hop.src_node_id.serialize()[..])?;
 364                         let short_channel_id = try_stretch(
 365                                 encode_int_be_base256(hop.short_channel_id),
 366                                 8
 367                         ).expect("sizeof(u64) == 8");
 368                         converter.append(&short_channel_id)?;
 369
 370                         let fee_base_msat = try_stretch(
 371                                 encode_int_be_base256(hop.fees.base_msat),
 372                                 4
 373                         ).expect("sizeof(u32) == 4");
 374                         converter.append(&fee_base_msat)?;
 375
 376                         let fee_proportional_millionths = try_stretch(
 377                                 encode_int_be_base256(hop.fees.proportional_millionths),
 378                                 4
 379                         ).expect("sizeof(u32) == 4");
 380                         converter.append(&fee_proportional_millionths)?;
 381
 382                         let cltv_expiry_delta = try_stretch(
 383                                 encode_int_be_base256(hop.cltv_expiry_delta),
 384                                 2
 385                         ).expect("sizeof(u16) == 2");
 386                         converter.append(&cltv_expiry_delta)?;
 387                 }
 388
 389                 converter.finalize()?;
 390                 Ok(())
 391         }
 392 }
 393
 394 impl Base32Len for RouteHint {
 395         fn base32_len(&self) -> usize {
 396                 bytes_size_to_base32_size(self.0.len() * 51)
 397         }
 398 }
 399
 400 impl ToBase32 for TaggedField {
 401         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 402                 /// Writes a tagged field: tag, length and data. `tag` should be in `0..32` otherwise the
 403                 /// function will panic.
 404                 fn write_tagged_field<W, P>(writer: &mut W, tag: u8, payload: &P) -> Result<(), W::Err>
 405                         where W: WriteBase32,
 406                                   P: ToBase32 + Base32Len,
 407                 {
 408                         let len = payload.base32_len();
 409                         assert!(len < 1024, "Every tagged field data can be at most 1023 bytes long.");
 410
 411                         writer.write_u5(u5::try_from_u8(tag).expect("invalid tag, not in 0..32"))?;
 412                         writer.write(&try_stretch(
 413                                 encode_int_be_base32(len as u64),
 414                                 2
 415                         ).expect("Can't be longer than 2, see assert above."))?;
 416                         payload.write_base32(writer)
 417                 }
 418
 419                 match *self {
 420                         TaggedField::PaymentHash(ref hash) => {
 421                                 write_tagged_field(writer, constants::TAG_PAYMENT_HASH, hash)
 422                         },
 423                         TaggedField::Description(ref description) => {
 424                                 write_tagged_field(writer, constants::TAG_DESCRIPTION, description)
 425                         },
 426                         TaggedField::PayeePubKey(ref pub_key) => {
 427                                 write_tagged_field(writer, constants::TAG_PAYEE_PUB_KEY, pub_key)
 428                         },
 429                         TaggedField::DescriptionHash(ref hash) => {
 430                                 write_tagged_field(writer, constants::TAG_DESCRIPTION_HASH, hash)
 431                         },
 432                         TaggedField::ExpiryTime(ref duration) => {
 433                                 write_tagged_field(writer, constants::TAG_EXPIRY_TIME, duration)
 434                         },
 435                         TaggedField::MinFinalCltvExpiry(ref expiry) => {
 436                                 write_tagged_field(writer, constants::TAG_MIN_FINAL_CLTV_EXPIRY, expiry)
 437                         },
 438                         TaggedField::Fallback(ref fallback_address) => {
 439                                 write_tagged_field(writer, constants::TAG_FALLBACK, fallback_address)
 440                         },
 441                         TaggedField::Route(ref route_hops) => {
 442                                 write_tagged_field(writer, constants::TAG_ROUTE, route_hops)
 443                         },
 444                         TaggedField::PaymentSecret(ref payment_secret) => {
 445                                   write_tagged_field(writer, constants::TAG_PAYMENT_SECRET, payment_secret)
 446                         },
 447                         TaggedField::Features(ref features) => {
 448                                 write_tagged_field(writer, constants::TAG_FEATURES, features)
 449                         },
 450                 }
 451         }
 452 }
 453
 454 impl ToBase32 for InvoiceSignature {
 455         fn write_base32<W: WriteBase32>(&self, writer: &mut W) -> Result<(), <W as WriteBase32>::Err> {
 456                 let mut converter = BytesToBase32::new(writer);
 457                 let (recovery_id, signature) = self.0.serialize_compact();
 458                 converter.append(&signature[..])?;
 459                 converter.append_u8(recovery_id.to_i32() as u8)?;
 460                 converter.finalize()
 461         }
 462 }
 463
 464 #[cfg(test)]
 465 mod test {
 466         use bech32::CheckBase32;
 467
 468         #[test]
 469         fn test_currency_code() {
 470                 use Currency;
 471
 472                 assert_eq!("bc", Currency::Bitcoin.to_string());
 473                 assert_eq!("tb", Currency::BitcoinTestnet.to_string());
 474                 assert_eq!("bcrt", Currency::Regtest.to_string());
 475                 assert_eq!("sb", Currency::Simnet.to_string());
 476         }
 477
 478         #[test]
 479         fn test_raw_hrp() {
 480                 use ::{Currency, RawHrp, SiPrefix};
 481
 482                 let hrp = RawHrp {
 483                         currency: Currency::Bitcoin,
 484                         raw_amount: Some(100),
 485                         si_prefix: Some(SiPrefix::Micro),
 486                 };
 487
 488                 assert_eq!(hrp.to_string(), "lnbc100u");
 489         }
 490
 491         #[test]
 492         fn test_encode_int_be_base32() {
 493                 use ser::encode_int_be_base32;
 494
 495                 let input: u64 = 33764;
 496                 let expected_out = CheckBase32::check_base32(&[1, 0, 31, 4]).unwrap();
 497
 498                 assert_eq!(expected_out, encode_int_be_base32(input));
 499         }
 500
 501         #[test]
 502         fn test_encode_int_be_base256() {
 503                 use ser::encode_int_be_base256;
 504
 505                 let input: u64 = 16842530;
 506                 let expected_out = vec![1, 0, 255, 34];
 507
 508                 assert_eq!(expected_out, encode_int_be_base256(input));
 509         }
 510 }