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

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! A very simple serialization framework which is used to serialize/deserialize messages as well
  11 //! as [`ChannelManager`]s and [`ChannelMonitor`]s.
  12 //!
  13 //! [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
  14 //! [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
  15
  16 use crate::prelude::*;
  17 use crate::io::{self, Read, Seek, Write};
  18 use crate::io_extras::{copy, sink};
  19 use core::hash::Hash;
  20 use crate::sync::Mutex;
  21 use core::cmp;
  22 use core::convert::TryFrom;
  23 use core::ops::Deref;
  24
  25 use bitcoin::secp256k1::{PublicKey, SecretKey};
  26 use bitcoin::secp256k1::constants::{PUBLIC_KEY_SIZE, SECRET_KEY_SIZE, COMPACT_SIGNATURE_SIZE, SCHNORR_SIGNATURE_SIZE};
  27 use bitcoin::secp256k1::ecdsa;
  28 use bitcoin::secp256k1::schnorr;
  29 use bitcoin::blockdata::constants::ChainHash;
  30 use bitcoin::blockdata::script::Script;
  31 use bitcoin::blockdata::transaction::{OutPoint, Transaction, TxOut};
  32 use bitcoin::consensus;
  33 use bitcoin::consensus::Encodable;
  34 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
  35 use bitcoin::hash_types::{Txid, BlockHash};
  36 use core::marker::Sized;
  37 use core::time::Duration;
  38 use crate::ln::msgs::DecodeError;
  39 use crate::ln::{PaymentPreimage, PaymentHash, PaymentSecret};
  40
  41 use crate::util::byte_utils::{be48_to_array, slice_to_be48};
  42
  43 /// serialization buffer size
  44 pub const MAX_BUF_SIZE: usize = 64 * 1024;
  45
  46 /// A simplified version of [`std::io::Write`] that exists largely for backwards compatibility.
  47 /// An impl is provided for any type that also impls [`std::io::Write`].
  48 ///
  49 /// (C-not exported) as we only export serialization to/from byte arrays instead
  50 pub trait Writer {
  51         /// Writes the given buf out. See std::io::Write::write_all for more
  52         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error>;
  53 }
  54
  55 impl<W: Write> Writer for W {
  56         #[inline]
  57         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
  58                 <Self as io::Write>::write_all(self, buf)
  59         }
  60 }
  61
  62 pub(crate) struct WriterWriteAdaptor<'a, W: Writer + 'a>(pub &'a mut W);
  63 impl<'a, W: Writer + 'a> Write for WriterWriteAdaptor<'a, W> {
  64         #[inline]
  65         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
  66                 self.0.write_all(buf)
  67         }
  68         #[inline]
  69         fn write(&mut self, buf: &[u8]) -> Result<usize, io::Error> {
  70                 self.0.write_all(buf)?;
  71                 Ok(buf.len())
  72         }
  73         #[inline]
  74         fn flush(&mut self) -> Result<(), io::Error> {
  75                 Ok(())
  76         }
  77 }
  78
  79 pub(crate) struct VecWriter(pub Vec<u8>);
  80 impl Writer for VecWriter {
  81         #[inline]
  82         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
  83                 self.0.extend_from_slice(buf);
  84                 Ok(())
  85         }
  86 }
  87
  88 /// Writer that only tracks the amount of data written - useful if you need to calculate the length
  89 /// of some data when serialized but don't yet need the full data.
  90 pub struct LengthCalculatingWriter(pub usize);
  91 impl Writer for LengthCalculatingWriter {
  92         #[inline]
  93         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
  94                 self.0 += buf.len();
  95                 Ok(())
  96         }
  97 }
  98
  99 /// Essentially [`std::io::Take`] but a bit simpler and with a method to walk the underlying stream
 100 /// forward to ensure we always consume exactly the fixed length specified.
 101 pub struct FixedLengthReader<R: Read> {
 102         read: R,
 103         bytes_read: u64,
 104         total_bytes: u64,
 105 }
 106 impl<R: Read> FixedLengthReader<R> {
 107         /// Returns a new [`FixedLengthReader`].
 108         pub fn new(read: R, total_bytes: u64) -> Self {
 109                 Self { read, bytes_read: 0, total_bytes }
 110         }
 111
 112         /// Returns whether some bytes are remaining or not.
 113         #[inline]
 114         pub fn bytes_remain(&mut self) -> bool {
 115                 self.bytes_read != self.total_bytes
 116         }
 117
 118         /// Consumes the remaining bytes.
 119         #[inline]
 120         pub fn eat_remaining(&mut self) -> Result<(), DecodeError> {
 121                 copy(self, &mut sink()).unwrap();
 122                 if self.bytes_read != self.total_bytes {
 123                         Err(DecodeError::ShortRead)
 124                 } else {
 125                         Ok(())
 126                 }
 127         }
 128 }
 129 impl<R: Read> Read for FixedLengthReader<R> {
 130         #[inline]
 131         fn read(&mut self, dest: &mut [u8]) -> Result<usize, io::Error> {
 132                 if self.total_bytes == self.bytes_read {
 133                         Ok(0)
 134                 } else {
 135                         let read_len = cmp::min(dest.len() as u64, self.total_bytes - self.bytes_read);
 136                         match self.read.read(&mut dest[0..(read_len as usize)]) {
 137                                 Ok(v) => {
 138                                         self.bytes_read += v as u64;
 139                                         Ok(v)
 140                                 },
 141                                 Err(e) => Err(e),
 142                         }
 143                 }
 144         }
 145 }
 146
 147 impl<R: Read> LengthRead for FixedLengthReader<R> {
 148         #[inline]
 149         fn total_bytes(&self) -> u64 {
 150                 self.total_bytes
 151         }
 152 }
 153
 154 /// A [`Read`] implementation which tracks whether any bytes have been read at all. This allows us to distinguish
 155 /// between "EOF reached before we started" and "EOF reached mid-read".
 156 pub struct ReadTrackingReader<R: Read> {
 157         read: R,
 158         /// Returns whether we have read from this reader or not yet.
 159         pub have_read: bool,
 160 }
 161 impl<R: Read> ReadTrackingReader<R> {
 162         /// Returns a new [`ReadTrackingReader`].
 163         pub fn new(read: R) -> Self {
 164                 Self { read, have_read: false }
 165         }
 166 }
 167 impl<R: Read> Read for ReadTrackingReader<R> {
 168         #[inline]
 169         fn read(&mut self, dest: &mut [u8]) -> Result<usize, io::Error> {
 170                 match self.read.read(dest) {
 171                         Ok(0) => Ok(0),
 172                         Ok(len) => {
 173                                 self.have_read = true;
 174                                 Ok(len)
 175                         },
 176                         Err(e) => Err(e),
 177                 }
 178         }
 179 }
 180
 181 /// A trait that various LDK types implement allowing them to be written out to a [`Writer`].
 182 ///
 183 /// (C-not exported) as we only export serialization to/from byte arrays instead
 184 pub trait Writeable {
 185         /// Writes `self` out to the given [`Writer`].
 186         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error>;
 187
 188         /// Writes `self` out to a `Vec<u8>`.
 189         fn encode(&self) -> Vec<u8> {
 190                 let mut msg = VecWriter(Vec::new());
 191                 self.write(&mut msg).unwrap();
 192                 msg.0
 193         }
 194
 195         /// Writes `self` out to a `Vec<u8>`.
 196         #[cfg(test)]
 197         fn encode_with_len(&self) -> Vec<u8> {
 198                 let mut msg = VecWriter(Vec::new());
 199                 0u16.write(&mut msg).unwrap();
 200                 self.write(&mut msg).unwrap();
 201                 let len = msg.0.len();
 202                 msg.0[..2].copy_from_slice(&(len as u16 - 2).to_be_bytes());
 203                 msg.0
 204         }
 205
 206         /// Gets the length of this object after it has been serialized. This can be overridden to
 207         /// optimize cases where we prepend an object with its length.
 208         // Note that LLVM optimizes this away in most cases! Check that it isn't before you override!
 209         #[inline]
 210         fn serialized_length(&self) -> usize {
 211                 let mut len_calc = LengthCalculatingWriter(0);
 212                 self.write(&mut len_calc).expect("No in-memory data may fail to serialize");
 213                 len_calc.0
 214         }
 215 }
 216
 217 impl<'a, T: Writeable> Writeable for &'a T {
 218         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { (*self).write(writer) }
 219 }
 220
 221 /// A trait that various LDK types implement allowing them to be read in from a [`Read`].
 222 ///
 223 /// (C-not exported) as we only export serialization to/from byte arrays instead
 224 pub trait Readable
 225         where Self: Sized
 226 {
 227         /// Reads a `Self` in from the given [`Read`].
 228         fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError>;
 229 }
 230
 231 /// A trait that various LDK types implement allowing them to be read in from a
 232 /// [`Read`]` + `[`Seek`].
 233 pub(crate) trait SeekReadable where Self: Sized {
 234         /// Reads a `Self` in from the given [`Read`].
 235         fn read<R: Read + Seek>(reader: &mut R) -> Result<Self, DecodeError>;
 236 }
 237
 238 /// A trait that various higher-level LDK types implement allowing them to be read in
 239 /// from a [`Read`] given some additional set of arguments which is required to deserialize.
 240 ///
 241 /// (C-not exported) as we only export serialization to/from byte arrays instead
 242 pub trait ReadableArgs<P>
 243         where Self: Sized
 244 {
 245         /// Reads a `Self` in from the given [`Read`].
 246         fn read<R: Read>(reader: &mut R, params: P) -> Result<Self, DecodeError>;
 247 }
 248
 249 /// A [`std::io::Read`] that also provides the total bytes available to be read.
 250 pub(crate) trait LengthRead: Read {
 251         /// The total number of bytes available to be read.
 252         fn total_bytes(&self) -> u64;
 253 }
 254
 255 /// A trait that various higher-level LDK types implement allowing them to be read in
 256 /// from a Read given some additional set of arguments which is required to deserialize, requiring
 257 /// the implementer to provide the total length of the read.
 258 pub(crate) trait LengthReadableArgs<P> where Self: Sized
 259 {
 260         /// Reads a `Self` in from the given [`LengthRead`].
 261         fn read<R: LengthRead>(reader: &mut R, params: P) -> Result<Self, DecodeError>;
 262 }
 263
 264 /// A trait that various higher-level LDK types implement allowing them to be read in
 265 /// from a [`Read`], requiring the implementer to provide the total length of the read.
 266 pub(crate) trait LengthReadable where Self: Sized
 267 {
 268         /// Reads a `Self` in from the given [`LengthRead`].
 269         fn read<R: LengthRead>(reader: &mut R) -> Result<Self, DecodeError>;
 270 }
 271
 272 /// A trait that various LDK types implement allowing them to (maybe) be read in from a [`Read`].
 273 ///
 274 /// (C-not exported) as we only export serialization to/from byte arrays instead
 275 pub trait MaybeReadable
 276         where Self: Sized
 277 {
 278         /// Reads a `Self` in from the given [`Read`].
 279         fn read<R: Read>(reader: &mut R) -> Result<Option<Self>, DecodeError>;
 280 }
 281
 282 impl<T: Readable> MaybeReadable for T {
 283         #[inline]
 284         fn read<R: Read>(reader: &mut R) -> Result<Option<T>, DecodeError> {
 285                 Ok(Some(Readable::read(reader)?))
 286         }
 287 }
 288
 289 /// Wrapper to read a required (non-optional) TLV record.
 290 pub struct OptionDeserWrapper<T: Readable>(pub Option<T>);
 291 impl<T: Readable> Readable for OptionDeserWrapper<T> {
 292         #[inline]
 293         fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError> {
 294                 Ok(Self(Some(Readable::read(reader)?)))
 295         }
 296 }
 297 /// When handling `default_values`, we want to map the default-value T directly
 298 /// to a `OptionDeserWrapper<T>` in a way that works for `field: T = t;` as
 299 /// well. Thus, we assume `Into<T> for T` does nothing and use that.
 300 impl<T: Readable> From<T> for OptionDeserWrapper<T> {
 301         fn from(t: T) -> OptionDeserWrapper<T> { OptionDeserWrapper(Some(t)) }
 302 }
 303
 304 pub(crate) struct U48(pub u64);
 305 impl Writeable for U48 {
 306         #[inline]
 307         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 308                 writer.write_all(&be48_to_array(self.0))
 309         }
 310 }
 311 impl Readable for U48 {
 312         #[inline]
 313         fn read<R: Read>(reader: &mut R) -> Result<U48, DecodeError> {
 314                 let mut buf = [0; 6];
 315                 reader.read_exact(&mut buf)?;
 316                 Ok(U48(slice_to_be48(&buf)))
 317         }
 318 }
 319
 320 /// Lightning TLV uses a custom variable-length integer called `BigSize`. It is similar to Bitcoin's
 321 /// variable-length integers except that it is serialized in big-endian instead of little-endian.
 322 ///
 323 /// Like Bitcoin's variable-length integer, it exhibits ambiguity in that certain values can be
 324 /// encoded in several different ways, which we must check for at deserialization-time. Thus, if
 325 /// you're looking for an example of a variable-length integer to use for your own project, move
 326 /// along, this is a rather poor design.
 327 pub struct BigSize(pub u64);
 328 impl Writeable for BigSize {
 329         #[inline]
 330         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 331                 match self.0 {
 332                         0...0xFC => {
 333                                 (self.0 as u8).write(writer)
 334                         },
 335                         0xFD...0xFFFF => {
 336                                 0xFDu8.write(writer)?;
 337                                 (self.0 as u16).write(writer)
 338                         },
 339                         0x10000...0xFFFFFFFF => {
 340                                 0xFEu8.write(writer)?;
 341                                 (self.0 as u32).write(writer)
 342                         },
 343                         _ => {
 344                                 0xFFu8.write(writer)?;
 345                                 (self.0 as u64).write(writer)
 346                         },
 347                 }
 348         }
 349 }
 350 impl Readable for BigSize {
 351         #[inline]
 352         fn read<R: Read>(reader: &mut R) -> Result<BigSize, DecodeError> {
 353                 let n: u8 = Readable::read(reader)?;
 354                 match n {
 355                         0xFF => {
 356                                 let x: u64 = Readable::read(reader)?;
 357                                 if x < 0x100000000 {
 358                                         Err(DecodeError::InvalidValue)
 359                                 } else {
 360                                         Ok(BigSize(x))
 361                                 }
 362                         }
 363                         0xFE => {
 364                                 let x: u32 = Readable::read(reader)?;
 365                                 if x < 0x10000 {
 366                                         Err(DecodeError::InvalidValue)
 367                                 } else {
 368                                         Ok(BigSize(x as u64))
 369                                 }
 370                         }
 371                         0xFD => {
 372                                 let x: u16 = Readable::read(reader)?;
 373                                 if x < 0xFD {
 374                                         Err(DecodeError::InvalidValue)
 375                                 } else {
 376                                         Ok(BigSize(x as u64))
 377                                 }
 378                         }
 379                         n => Ok(BigSize(n as u64))
 380                 }
 381         }
 382 }
 383
 384 /// In TLV we occasionally send fields which only consist of, or potentially end with, a
 385 /// variable-length integer which is simply truncated by skipping high zero bytes. This type
 386 /// encapsulates such integers implementing [`Readable`]/[`Writeable`] for them.
 387 #[cfg_attr(test, derive(PartialEq, Eq, Debug))]
 388 pub(crate) struct HighZeroBytesDroppedBigSize<T>(pub T);
 389
 390 macro_rules! impl_writeable_primitive {
 391         ($val_type:ty, $len: expr) => {
 392                 impl Writeable for $val_type {
 393                         #[inline]
 394                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 395                                 writer.write_all(&self.to_be_bytes())
 396                         }
 397                 }
 398                 impl Writeable for HighZeroBytesDroppedBigSize<$val_type> {
 399                         #[inline]
 400                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 401                                 // Skip any full leading 0 bytes when writing (in BE):
 402                                 writer.write_all(&self.0.to_be_bytes()[(self.0.leading_zeros()/8) as usize..$len])
 403                         }
 404                 }
 405                 impl Readable for $val_type {
 406                         #[inline]
 407                         fn read<R: Read>(reader: &mut R) -> Result<$val_type, DecodeError> {
 408                                 let mut buf = [0; $len];
 409                                 reader.read_exact(&mut buf)?;
 410                                 Ok(<$val_type>::from_be_bytes(buf))
 411                         }
 412                 }
 413                 impl Readable for HighZeroBytesDroppedBigSize<$val_type> {
 414                         #[inline]
 415                         fn read<R: Read>(reader: &mut R) -> Result<HighZeroBytesDroppedBigSize<$val_type>, DecodeError> {
 416                                 // We need to accept short reads (read_len == 0) as "EOF" and handle them as simply
 417                                 // the high bytes being dropped. To do so, we start reading into the middle of buf
 418                                 // and then convert the appropriate number of bytes with extra high bytes out of
 419                                 // buf.
 420                                 let mut buf = [0; $len*2];
 421                                 let mut read_len = reader.read(&mut buf[$len..])?;
 422                                 let mut total_read_len = read_len;
 423                                 while read_len != 0 && total_read_len != $len {
 424                                         read_len = reader.read(&mut buf[($len + total_read_len)..])?;
 425                                         total_read_len += read_len;
 426                                 }
 427                                 if total_read_len == 0 || buf[$len] != 0 {
 428                                         let first_byte = $len - ($len - total_read_len);
 429                                         let mut bytes = [0; $len];
 430                                         bytes.copy_from_slice(&buf[first_byte..first_byte + $len]);
 431                                         Ok(HighZeroBytesDroppedBigSize(<$val_type>::from_be_bytes(bytes)))
 432                                 } else {
 433                                         // If the encoding had extra zero bytes, return a failure even though we know
 434                                         // what they meant (as the TLV test vectors require this)
 435                                         Err(DecodeError::InvalidValue)
 436                                 }
 437                         }
 438                 }
 439                 impl From<$val_type> for HighZeroBytesDroppedBigSize<$val_type> {
 440                         fn from(val: $val_type) -> Self { Self(val) }
 441                 }
 442         }
 443 }
 444
 445 impl_writeable_primitive!(u128, 16);
 446 impl_writeable_primitive!(u64, 8);
 447 impl_writeable_primitive!(u32, 4);
 448 impl_writeable_primitive!(u16, 2);
 449
 450 impl Writeable for u8 {
 451         #[inline]
 452         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 453                 writer.write_all(&[*self])
 454         }
 455 }
 456 impl Readable for u8 {
 457         #[inline]
 458         fn read<R: Read>(reader: &mut R) -> Result<u8, DecodeError> {
 459                 let mut buf = [0; 1];
 460                 reader.read_exact(&mut buf)?;
 461                 Ok(buf[0])
 462         }
 463 }
 464
 465 impl Writeable for bool {
 466         #[inline]
 467         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 468                 writer.write_all(&[if *self {1} else {0}])
 469         }
 470 }
 471 impl Readable for bool {
 472         #[inline]
 473         fn read<R: Read>(reader: &mut R) -> Result<bool, DecodeError> {
 474                 let mut buf = [0; 1];
 475                 reader.read_exact(&mut buf)?;
 476                 if buf[0] != 0 && buf[0] != 1 {
 477                         return Err(DecodeError::InvalidValue);
 478                 }
 479                 Ok(buf[0] == 1)
 480         }
 481 }
 482
 483 // u8 arrays
 484 macro_rules! impl_array {
 485         ( $size:expr ) => (
 486                 impl Writeable for [u8; $size]
 487                 {
 488                         #[inline]
 489                         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 490                                 w.write_all(self)
 491                         }
 492                 }
 493
 494                 impl Readable for [u8; $size]
 495                 {
 496                         #[inline]
 497                         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 498                                 let mut buf = [0u8; $size];
 499                                 r.read_exact(&mut buf)?;
 500                                 Ok(buf)
 501                         }
 502                 }
 503         );
 504 }
 505
 506 impl_array!(3); // for rgb, ISO 4712 code
 507 impl_array!(4); // for IPv4
 508 impl_array!(12); // for OnionV2
 509 impl_array!(16); // for IPv6
 510 impl_array!(32); // for channel id & hmac
 511 impl_array!(PUBLIC_KEY_SIZE); // for PublicKey
 512 impl_array!(64); // for ecdsa::Signature and schnorr::Signature
 513 impl_array!(1300); // for OnionPacket.hop_data
 514
 515 impl Writeable for [u16; 8] {
 516         #[inline]
 517         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 518                 for v in self.iter() {
 519                         w.write_all(&v.to_be_bytes())?
 520                 }
 521                 Ok(())
 522         }
 523 }
 524
 525 impl Readable for [u16; 8] {
 526         #[inline]
 527         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 528                 let mut buf = [0u8; 16];
 529                 r.read_exact(&mut buf)?;
 530                 let mut res = [0u16; 8];
 531                 for (idx, v) in res.iter_mut().enumerate() {
 532                         *v = (buf[idx] as u16) << 8 | (buf[idx + 1] as u16)
 533                 }
 534                 Ok(res)
 535         }
 536 }
 537
 538 /// A type for variable-length values within TLV record where the length is encoded as part of the record.
 539 /// Used to prevent encoding the length twice.
 540 pub struct WithoutLength<T>(pub T);
 541
 542 impl Writeable for WithoutLength<&String> {
 543         #[inline]
 544         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 545                 w.write_all(self.0.as_bytes())
 546         }
 547 }
 548 impl Readable for WithoutLength<String> {
 549         #[inline]
 550         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 551                 let v: WithoutLength<Vec<u8>> = Readable::read(r)?;
 552                 Ok(Self(String::from_utf8(v.0).map_err(|_| DecodeError::InvalidValue)?))
 553         }
 554 }
 555 impl<'a> From<&'a String> for WithoutLength<&'a String> {
 556         fn from(s: &'a String) -> Self { Self(s) }
 557 }
 558
 559 impl<'a, T: Writeable> Writeable for WithoutLength<&'a Vec<T>> {
 560         #[inline]
 561         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 562                 for ref v in self.0.iter() {
 563                         v.write(writer)?;
 564                 }
 565                 Ok(())
 566         }
 567 }
 568
 569 impl<T: MaybeReadable> Readable for WithoutLength<Vec<T>> {
 570         #[inline]
 571         fn read<R: Read>(mut reader: &mut R) -> Result<Self, DecodeError> {
 572                 let mut values = Vec::new();
 573                 loop {
 574                         let mut track_read = ReadTrackingReader::new(&mut reader);
 575                         match MaybeReadable::read(&mut track_read) {
 576                                 Ok(Some(v)) => { values.push(v); },
 577                                 Ok(None) => { },
 578                                 // If we failed to read any bytes at all, we reached the end of our TLV
 579                                 // stream and have simply exhausted all entries.
 580                                 Err(ref e) if e == &DecodeError::ShortRead && !track_read.have_read => break,
 581                                 Err(e) => return Err(e),
 582                         }
 583                 }
 584                 Ok(Self(values))
 585         }
 586 }
 587 impl<'a, T> From<&'a Vec<T>> for WithoutLength<&'a Vec<T>> {
 588         fn from(v: &'a Vec<T>) -> Self { Self(v) }
 589 }
 590
 591 // HashMap
 592 impl<K, V> Writeable for HashMap<K, V>
 593         where K: Writeable + Eq + Hash,
 594               V: Writeable
 595 {
 596         #[inline]
 597         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 598         (self.len() as u16).write(w)?;
 599                 for (key, value) in self.iter() {
 600                         key.write(w)?;
 601                         value.write(w)?;
 602                 }
 603                 Ok(())
 604         }
 605 }
 606
 607 impl<K, V> Readable for HashMap<K, V>
 608         where K: Readable + Eq + Hash,
 609               V: MaybeReadable
 610 {
 611         #[inline]
 612         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 613                 let len: u16 = Readable::read(r)?;
 614                 let mut ret = HashMap::with_capacity(len as usize);
 615                 for _ in 0..len {
 616                         let k = K::read(r)?;
 617                         let v_opt = V::read(r)?;
 618                         if let Some(v) = v_opt {
 619                                 if ret.insert(k, v).is_some() {
 620                                         return Err(DecodeError::InvalidValue);
 621                                 }
 622                         }
 623                 }
 624                 Ok(ret)
 625         }
 626 }
 627
 628 // HashSet
 629 impl<T> Writeable for HashSet<T>
 630 where T: Writeable + Eq + Hash
 631 {
 632         #[inline]
 633         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 634                 (self.len() as u16).write(w)?;
 635                 for item in self.iter() {
 636                         item.write(w)?;
 637                 }
 638                 Ok(())
 639         }
 640 }
 641
 642 impl<T> Readable for HashSet<T>
 643 where T: Readable + Eq + Hash
 644 {
 645         #[inline]
 646         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 647                 let len: u16 = Readable::read(r)?;
 648                 let mut ret = HashSet::with_capacity(len as usize);
 649                 for _ in 0..len {
 650                         if !ret.insert(T::read(r)?) {
 651                                 return Err(DecodeError::InvalidValue)
 652                         }
 653                 }
 654                 Ok(ret)
 655         }
 656 }
 657
 658 // Vectors
 659 impl Writeable for Vec<u8> {
 660         #[inline]
 661         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 662                 (self.len() as u16).write(w)?;
 663                 w.write_all(&self)
 664         }
 665 }
 666
 667 impl Readable for Vec<u8> {
 668         #[inline]
 669         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 670                 let len: u16 = Readable::read(r)?;
 671                 let mut ret = Vec::with_capacity(len as usize);
 672                 ret.resize(len as usize, 0);
 673                 r.read_exact(&mut ret)?;
 674                 Ok(ret)
 675         }
 676 }
 677 impl Writeable for Vec<ecdsa::Signature> {
 678         #[inline]
 679         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 680                 (self.len() as u16).write(w)?;
 681                 for e in self.iter() {
 682                         e.write(w)?;
 683                 }
 684                 Ok(())
 685         }
 686 }
 687
 688 impl Readable for Vec<ecdsa::Signature> {
 689         #[inline]
 690         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 691                 let len: u16 = Readable::read(r)?;
 692                 let byte_size = (len as usize)
 693                                 .checked_mul(COMPACT_SIGNATURE_SIZE)
 694                                 .ok_or(DecodeError::BadLengthDescriptor)?;
 695                 if byte_size > MAX_BUF_SIZE {
 696                         return Err(DecodeError::BadLengthDescriptor);
 697                 }
 698                 let mut ret = Vec::with_capacity(len as usize);
 699                 for _ in 0..len { ret.push(Readable::read(r)?); }
 700                 Ok(ret)
 701         }
 702 }
 703
 704 impl Writeable for Script {
 705         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 706                 (self.len() as u16).write(w)?;
 707                 w.write_all(self.as_bytes())
 708         }
 709 }
 710
 711 impl Readable for Script {
 712         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 713                 let len = <u16 as Readable>::read(r)? as usize;
 714                 let mut buf = vec![0; len];
 715                 r.read_exact(&mut buf)?;
 716                 Ok(Script::from(buf))
 717         }
 718 }
 719
 720 impl Writeable for PublicKey {
 721         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 722                 self.serialize().write(w)
 723         }
 724         #[inline]
 725         fn serialized_length(&self) -> usize {
 726                 PUBLIC_KEY_SIZE
 727         }
 728 }
 729
 730 impl Readable for PublicKey {
 731         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 732                 let buf: [u8; PUBLIC_KEY_SIZE] = Readable::read(r)?;
 733                 match PublicKey::from_slice(&buf) {
 734                         Ok(key) => Ok(key),
 735                         Err(_) => return Err(DecodeError::InvalidValue),
 736                 }
 737         }
 738 }
 739
 740 impl Writeable for SecretKey {
 741         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 742                 let mut ser = [0; SECRET_KEY_SIZE];
 743                 ser.copy_from_slice(&self[..]);
 744                 ser.write(w)
 745         }
 746         #[inline]
 747         fn serialized_length(&self) -> usize {
 748                 SECRET_KEY_SIZE
 749         }
 750 }
 751
 752 impl Readable for SecretKey {
 753         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 754                 let buf: [u8; SECRET_KEY_SIZE] = Readable::read(r)?;
 755                 match SecretKey::from_slice(&buf) {
 756                         Ok(key) => Ok(key),
 757                         Err(_) => return Err(DecodeError::InvalidValue),
 758                 }
 759         }
 760 }
 761
 762 impl Writeable for Sha256dHash {
 763         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 764                 w.write_all(&self[..])
 765         }
 766 }
 767
 768 impl Readable for Sha256dHash {
 769         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 770                 use bitcoin::hashes::Hash;
 771
 772                 let buf: [u8; 32] = Readable::read(r)?;
 773                 Ok(Sha256dHash::from_slice(&buf[..]).unwrap())
 774         }
 775 }
 776
 777 impl Writeable for ecdsa::Signature {
 778         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 779                 self.serialize_compact().write(w)
 780         }
 781 }
 782
 783 impl Readable for ecdsa::Signature {
 784         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 785                 let buf: [u8; COMPACT_SIGNATURE_SIZE] = Readable::read(r)?;
 786                 match ecdsa::Signature::from_compact(&buf) {
 787                         Ok(sig) => Ok(sig),
 788                         Err(_) => return Err(DecodeError::InvalidValue),
 789                 }
 790         }
 791 }
 792
 793 impl Writeable for schnorr::Signature {
 794         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 795                 self.as_ref().write(w)
 796         }
 797 }
 798
 799 impl Readable for schnorr::Signature {
 800         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 801                 let buf: [u8; SCHNORR_SIGNATURE_SIZE] = Readable::read(r)?;
 802                 match schnorr::Signature::from_slice(&buf) {
 803                         Ok(sig) => Ok(sig),
 804                         Err(_) => return Err(DecodeError::InvalidValue),
 805                 }
 806         }
 807 }
 808
 809 impl Writeable for PaymentPreimage {
 810         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 811                 self.0.write(w)
 812         }
 813 }
 814
 815 impl Readable for PaymentPreimage {
 816         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 817                 let buf: [u8; 32] = Readable::read(r)?;
 818                 Ok(PaymentPreimage(buf))
 819         }
 820 }
 821
 822 impl Writeable for PaymentHash {
 823         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 824                 self.0.write(w)
 825         }
 826 }
 827
 828 impl Readable for PaymentHash {
 829         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 830                 let buf: [u8; 32] = Readable::read(r)?;
 831                 Ok(PaymentHash(buf))
 832         }
 833 }
 834
 835 impl Writeable for PaymentSecret {
 836         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 837                 self.0.write(w)
 838         }
 839 }
 840
 841 impl Readable for PaymentSecret {
 842         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 843                 let buf: [u8; 32] = Readable::read(r)?;
 844                 Ok(PaymentSecret(buf))
 845         }
 846 }
 847
 848 impl<T: Writeable> Writeable for Box<T> {
 849         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 850                 T::write(&**self, w)
 851         }
 852 }
 853
 854 impl<T: Readable> Readable for Box<T> {
 855         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 856                 Ok(Box::new(Readable::read(r)?))
 857         }
 858 }
 859
 860 impl<T: Writeable> Writeable for Option<T> {
 861         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 862                 match *self {
 863                         None => 0u8.write(w)?,
 864                         Some(ref data) => {
 865                                 BigSize(data.serialized_length() as u64 + 1).write(w)?;
 866                                 data.write(w)?;
 867                         }
 868                 }
 869                 Ok(())
 870         }
 871 }
 872
 873 impl<T: Readable> Readable for Option<T>
 874 {
 875         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 876                 let len: BigSize = Readable::read(r)?;
 877                 match len.0 {
 878                         0 => Ok(None),
 879                         len => {
 880                                 let mut reader = FixedLengthReader::new(r, len - 1);
 881                                 Ok(Some(Readable::read(&mut reader)?))
 882                         }
 883                 }
 884         }
 885 }
 886
 887 impl Writeable for Txid {
 888         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 889                 w.write_all(&self[..])
 890         }
 891 }
 892
 893 impl Readable for Txid {
 894         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 895                 use bitcoin::hashes::Hash;
 896
 897                 let buf: [u8; 32] = Readable::read(r)?;
 898                 Ok(Txid::from_slice(&buf[..]).unwrap())
 899         }
 900 }
 901
 902 impl Writeable for BlockHash {
 903         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 904                 w.write_all(&self[..])
 905         }
 906 }
 907
 908 impl Readable for BlockHash {
 909         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 910                 use bitcoin::hashes::Hash;
 911
 912                 let buf: [u8; 32] = Readable::read(r)?;
 913                 Ok(BlockHash::from_slice(&buf[..]).unwrap())
 914         }
 915 }
 916
 917 impl Writeable for ChainHash {
 918         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 919                 w.write_all(self.as_bytes())
 920         }
 921 }
 922
 923 impl Readable for ChainHash {
 924         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 925                 let buf: [u8; 32] = Readable::read(r)?;
 926                 Ok(ChainHash::from(&buf[..]))
 927         }
 928 }
 929
 930 impl Writeable for OutPoint {
 931         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 932                 self.txid.write(w)?;
 933                 self.vout.write(w)?;
 934                 Ok(())
 935         }
 936 }
 937
 938 impl Readable for OutPoint {
 939         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 940                 let txid = Readable::read(r)?;
 941                 let vout = Readable::read(r)?;
 942                 Ok(OutPoint {
 943                         txid,
 944                         vout,
 945                 })
 946         }
 947 }
 948
 949 macro_rules! impl_consensus_ser {
 950         ($bitcoin_type: ty) => {
 951                 impl Writeable for $bitcoin_type {
 952                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 953                                 match self.consensus_encode(&mut WriterWriteAdaptor(writer)) {
 954                                         Ok(_) => Ok(()),
 955                                         Err(e) => Err(e),
 956                                 }
 957                         }
 958                 }
 959
 960                 impl Readable for $bitcoin_type {
 961                         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 962                                 match consensus::encode::Decodable::consensus_decode(r) {
 963                                         Ok(t) => Ok(t),
 964                                         Err(consensus::encode::Error::Io(ref e)) if e.kind() == io::ErrorKind::UnexpectedEof => Err(DecodeError::ShortRead),
 965                                         Err(consensus::encode::Error::Io(e)) => Err(DecodeError::Io(e.kind())),
 966                                         Err(_) => Err(DecodeError::InvalidValue),
 967                                 }
 968                         }
 969                 }
 970         }
 971 }
 972 impl_consensus_ser!(Transaction);
 973 impl_consensus_ser!(TxOut);
 974
 975 impl<T: Readable> Readable for Mutex<T> {
 976         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 977                 let t: T = Readable::read(r)?;
 978                 Ok(Mutex::new(t))
 979         }
 980 }
 981 impl<T: Writeable> Writeable for Mutex<T> {
 982         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 983                 self.lock().unwrap().write(w)
 984         }
 985 }
 986
 987 impl<A: Readable, B: Readable> Readable for (A, B) {
 988         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 989                 let a: A = Readable::read(r)?;
 990                 let b: B = Readable::read(r)?;
 991                 Ok((a, b))
 992         }
 993 }
 994 impl<A: Writeable, B: Writeable> Writeable for (A, B) {
 995         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 996                 self.0.write(w)?;
 997                 self.1.write(w)
 998         }
 999 }
1000
1001 impl<A: Readable, B: Readable, C: Readable> Readable for (A, B, C) {
1002         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
1003                 let a: A = Readable::read(r)?;
1004                 let b: B = Readable::read(r)?;
1005                 let c: C = Readable::read(r)?;
1006                 Ok((a, b, c))
1007         }
1008 }
1009 impl<A: Writeable, B: Writeable, C: Writeable> Writeable for (A, B, C) {
1010         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
1011                 self.0.write(w)?;
1012                 self.1.write(w)?;
1013                 self.2.write(w)
1014         }
1015 }
1016
1017 impl Writeable for () {
1018         fn write<W: Writer>(&self, _: &mut W) -> Result<(), io::Error> {
1019                 Ok(())
1020         }
1021 }
1022 impl Readable for () {
1023         fn read<R: Read>(_r: &mut R) -> Result<Self, DecodeError> {
1024                 Ok(())
1025         }
1026 }
1027
1028 impl Writeable for String {
1029         #[inline]
1030         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
1031                 (self.len() as u16).write(w)?;
1032                 w.write_all(self.as_bytes())
1033         }
1034 }
1035 impl Readable for String {
1036         #[inline]
1037         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
1038                 let v: Vec<u8> = Readable::read(r)?;
1039                 let ret = String::from_utf8(v).map_err(|_| DecodeError::InvalidValue)?;
1040                 Ok(ret)
1041         }
1042 }
1043
1044 /// Represents a hostname for serialization purposes.
1045 /// Only the character set and length will be validated.
1046 /// The character set consists of ASCII alphanumeric characters, hyphens, and periods.
1047 /// Its length is guaranteed to be representable by a single byte.
1048 /// This serialization is used by [`BOLT 7`] hostnames.
1049 ///
1050 /// [`BOLT 7`]: https://github.com/lightning/bolts/blob/master/07-routing-gossip.md
1051 #[derive(Clone, Debug, PartialEq, Eq)]
1052 pub struct Hostname(String);
1053 impl Hostname {
1054         /// Returns the length of the hostname.
1055         pub fn len(&self) -> u8 {
1056                 (&self.0).len() as u8
1057         }
1058 }
1059 impl Deref for Hostname {
1060         type Target = String;
1061
1062         fn deref(&self) -> &Self::Target {
1063                 &self.0
1064         }
1065 }
1066 impl From<Hostname> for String {
1067         fn from(hostname: Hostname) -> Self {
1068                 hostname.0
1069         }
1070 }
1071 impl TryFrom<Vec<u8>> for Hostname {
1072         type Error = ();
1073
1074         fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
1075                 if let Ok(s) = String::from_utf8(bytes) {
1076                         Hostname::try_from(s)
1077                 } else {
1078                         Err(())
1079                 }
1080         }
1081 }
1082 impl TryFrom<String> for Hostname {
1083         type Error = ();
1084
1085         fn try_from(s: String) -> Result<Self, Self::Error> {
1086                 if s.len() <= 255 && s.chars().all(|c|
1087                         c.is_ascii_alphanumeric() ||
1088                         c == '.' ||
1089                         c == '-'
1090                 ) {
1091                         Ok(Hostname(s))
1092                 } else {
1093                         Err(())
1094                 }
1095         }
1096 }
1097 impl Writeable for Hostname {
1098         #[inline]
1099         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
1100                 self.len().write(w)?;
1101                 w.write_all(self.as_bytes())
1102         }
1103 }
1104 impl Readable for Hostname {
1105         #[inline]
1106         fn read<R: Read>(r: &mut R) -> Result<Hostname, DecodeError> {
1107                 let len: u8 = Readable::read(r)?;
1108                 let mut vec = Vec::with_capacity(len.into());
1109                 vec.resize(len.into(), 0);
1110                 r.read_exact(&mut vec)?;
1111                 Hostname::try_from(vec).map_err(|_| DecodeError::InvalidValue)
1112         }
1113 }
1114
1115 impl Writeable for Duration {
1116         #[inline]
1117         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
1118                 self.as_secs().write(w)?;
1119                 self.subsec_nanos().write(w)
1120         }
1121 }
1122 impl Readable for Duration {
1123         #[inline]
1124         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
1125                 let secs = Readable::read(r)?;
1126                 let nanos = Readable::read(r)?;
1127                 Ok(Duration::new(secs, nanos))
1128         }
1129 }
1130
1131 #[cfg(test)]
1132 mod tests {
1133         use core::convert::TryFrom;
1134         use crate::util::ser::{Readable, Hostname, Writeable};
1135
1136         #[test]
1137         fn hostname_conversion() {
1138                 assert_eq!(Hostname::try_from(String::from("a-test.com")).unwrap().as_str(), "a-test.com");
1139
1140                 assert!(Hostname::try_from(String::from("\"")).is_err());
1141                 assert!(Hostname::try_from(String::from("$")).is_err());
1142                 assert!(Hostname::try_from(String::from("⚡")).is_err());
1143                 let mut large_vec = Vec::with_capacity(256);
1144                 large_vec.resize(256, b'A');
1145                 assert!(Hostname::try_from(String::from_utf8(large_vec).unwrap()).is_err());
1146         }
1147
1148         #[test]
1149         fn hostname_serialization() {
1150                 let hostname = Hostname::try_from(String::from("test")).unwrap();
1151                 let mut buf: Vec<u8> = Vec::new();
1152                 hostname.write(&mut buf).unwrap();
1153                 assert_eq!(Hostname::read(&mut buf.as_slice()).unwrap().as_str(), "test");
1154         }
1155 }