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