_ 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::Signature;
  21 use bitcoin::secp256k1::key::{PublicKey, SecretKey};
  22 use bitcoin::secp256k1::constants::{PUBLIC_KEY_SIZE, SECRET_KEY_SIZE, COMPACT_SIGNATURE_SIZE};
  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 ln::msgs::DecodeError;
  31 use ln::{PaymentPreimage, PaymentHash, PaymentSecret};
  32
  33 use util::byte_utils::{be48_to_array, slice_to_be48};
  34
  35 /// serialization buffer size
  36 pub const MAX_BUF_SIZE: usize = 64 * 1024;
  37
  38 /// A simplified version of std::io::Write that exists largely for backwards compatibility.
  39 /// An impl is provided for any type that also impls std::io::Write.
  40 ///
  41 /// (C-not exported) as we only export serialization to/from byte arrays instead
  42 pub trait Writer {
  43         /// Writes the given buf out. See std::io::Write::write_all for more
  44         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error>;
  45 }
  46
  47 impl<W: Write> Writer for W {
  48         #[inline]
  49         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
  50                 <Self as io::Write>::write_all(self, buf)
  51         }
  52 }
  53
  54 pub(crate) struct WriterWriteAdaptor<'a, W: Writer + 'a>(pub &'a mut W);
  55 impl<'a, W: Writer + 'a> Write for WriterWriteAdaptor<'a, W> {
  56         #[inline]
  57         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
  58                 self.0.write_all(buf)
  59         }
  60         #[inline]
  61         fn write(&mut self, buf: &[u8]) -> Result<usize, io::Error> {
  62                 self.0.write_all(buf)?;
  63                 Ok(buf.len())
  64         }
  65         #[inline]
  66         fn flush(&mut self) -> Result<(), io::Error> {
  67                 Ok(())
  68         }
  69 }
  70
  71 pub(crate) struct VecWriter(pub Vec<u8>);
  72 impl Writer for VecWriter {
  73         #[inline]
  74         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
  75                 self.0.extend_from_slice(buf);
  76                 Ok(())
  77         }
  78 }
  79
  80 /// Writer that only tracks the amount of data written - useful if you need to calculate the length
  81 /// of some data when serialized but don't yet need the full data.
  82 pub(crate) struct LengthCalculatingWriter(pub usize);
  83 impl Writer for LengthCalculatingWriter {
  84         #[inline]
  85         fn write_all(&mut self, buf: &[u8]) -> Result<(), io::Error> {
  86                 self.0 += buf.len();
  87                 Ok(())
  88         }
  89 }
  90
  91 /// Essentially std::io::Take but a bit simpler and with a method to walk the underlying stream
  92 /// forward to ensure we always consume exactly the fixed length specified.
  93 pub(crate) struct FixedLengthReader<R: Read> {
  94         read: R,
  95         bytes_read: u64,
  96         total_bytes: u64,
  97 }
  98 impl<R: Read> FixedLengthReader<R> {
  99         pub fn new(read: R, total_bytes: u64) -> Self {
 100                 Self { read, bytes_read: 0, total_bytes }
 101         }
 102
 103         #[inline]
 104         pub fn bytes_remain(&mut self) -> bool {
 105                 self.bytes_read != self.total_bytes
 106         }
 107
 108         #[inline]
 109         pub fn eat_remaining(&mut self) -> Result<(), DecodeError> {
 110                 copy(self, &mut sink()).unwrap();
 111                 if self.bytes_read != self.total_bytes {
 112                         Err(DecodeError::ShortRead)
 113                 } else {
 114                         Ok(())
 115                 }
 116         }
 117 }
 118 impl<R: Read> Read for FixedLengthReader<R> {
 119         #[inline]
 120         fn read(&mut self, dest: &mut [u8]) -> Result<usize, io::Error> {
 121                 if self.total_bytes == self.bytes_read {
 122                         Ok(0)
 123                 } else {
 124                         let read_len = cmp::min(dest.len() as u64, self.total_bytes - self.bytes_read);
 125                         match self.read.read(&mut dest[0..(read_len as usize)]) {
 126                                 Ok(v) => {
 127                                         self.bytes_read += v as u64;
 128                                         Ok(v)
 129                                 },
 130                                 Err(e) => Err(e),
 131                         }
 132                 }
 133         }
 134 }
 135
 136 /// A Read which tracks whether any bytes have been read at all. This allows us to distinguish
 137 /// between "EOF reached before we started" and "EOF reached mid-read".
 138 pub(crate) struct ReadTrackingReader<R: Read> {
 139         read: R,
 140         pub have_read: bool,
 141 }
 142 impl<R: Read> ReadTrackingReader<R> {
 143         pub fn new(read: R) -> Self {
 144                 Self { read, have_read: false }
 145         }
 146 }
 147 impl<R: Read> Read for ReadTrackingReader<R> {
 148         #[inline]
 149         fn read(&mut self, dest: &mut [u8]) -> Result<usize, io::Error> {
 150                 match self.read.read(dest) {
 151                         Ok(0) => Ok(0),
 152                         Ok(len) => {
 153                                 self.have_read = true;
 154                                 Ok(len)
 155                         },
 156                         Err(e) => Err(e),
 157                 }
 158         }
 159 }
 160
 161 /// A trait that various rust-lightning types implement allowing them to be written out to a Writer
 162 ///
 163 /// (C-not exported) as we only export serialization to/from byte arrays instead
 164 pub trait Writeable {
 165         /// Writes self out to the given Writer
 166         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error>;
 167
 168         /// Writes self out to a Vec<u8>
 169         fn encode(&self) -> Vec<u8> {
 170                 let mut msg = VecWriter(Vec::new());
 171                 self.write(&mut msg).unwrap();
 172                 msg.0
 173         }
 174
 175         /// Writes self out to a Vec<u8>
 176         fn encode_with_len(&self) -> Vec<u8> {
 177                 let mut msg = VecWriter(Vec::new());
 178                 0u16.write(&mut msg).unwrap();
 179                 self.write(&mut msg).unwrap();
 180                 let len = msg.0.len();
 181                 msg.0[..2].copy_from_slice(&(len as u16 - 2).to_be_bytes());
 182                 msg.0
 183         }
 184
 185         /// Gets the length of this object after it has been serialized. This can be overridden to
 186         /// optimize cases where we prepend an object with its length.
 187         // Note that LLVM optimizes this away in most cases! Check that it isn't before you override!
 188         #[inline]
 189         fn serialized_length(&self) -> usize {
 190                 let mut len_calc = LengthCalculatingWriter(0);
 191                 self.write(&mut len_calc).expect("No in-memory data may fail to serialize");
 192                 len_calc.0
 193         }
 194 }
 195
 196 impl<'a, T: Writeable> Writeable for &'a T {
 197         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> { (*self).write(writer) }
 198 }
 199
 200 /// A trait that various rust-lightning types implement allowing them to be read in from a Read
 201 ///
 202 /// (C-not exported) as we only export serialization to/from byte arrays instead
 203 pub trait Readable
 204         where Self: Sized
 205 {
 206         /// Reads a Self in from the given Read
 207         fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError>;
 208 }
 209
 210 /// A trait that various higher-level rust-lightning types implement allowing them to be read in
 211 /// from a Read given some additional set of arguments which is required to deserialize.
 212 ///
 213 /// (C-not exported) as we only export serialization to/from byte arrays instead
 214 pub trait ReadableArgs<P>
 215         where Self: Sized
 216 {
 217         /// Reads a Self in from the given Read
 218         fn read<R: Read>(reader: &mut R, params: P) -> Result<Self, DecodeError>;
 219 }
 220
 221 /// A trait that various rust-lightning types implement allowing them to (maybe) be read in from a Read
 222 ///
 223 /// (C-not exported) as we only export serialization to/from byte arrays instead
 224 pub trait MaybeReadable
 225         where Self: Sized
 226 {
 227         /// Reads a Self in from the given Read
 228         fn read<R: Read>(reader: &mut R) -> Result<Option<Self>, DecodeError>;
 229 }
 230
 231 impl<T: Readable> MaybeReadable for T {
 232         #[inline]
 233         fn read<R: Read>(reader: &mut R) -> Result<Option<T>, DecodeError> {
 234                 Ok(Some(Readable::read(reader)?))
 235         }
 236 }
 237
 238 pub(crate) struct OptionDeserWrapper<T: Readable>(pub Option<T>);
 239 impl<T: Readable> Readable for OptionDeserWrapper<T> {
 240         #[inline]
 241         fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError> {
 242                 Ok(Self(Some(Readable::read(reader)?)))
 243         }
 244 }
 245
 246 /// Wrapper to write each element of a Vec with no length prefix
 247 pub(crate) struct VecWriteWrapper<'a, T: Writeable>(pub &'a Vec<T>);
 248 impl<'a, T: Writeable> Writeable for VecWriteWrapper<'a, T> {
 249         #[inline]
 250         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 251                 for ref v in self.0.iter() {
 252                         v.write(writer)?;
 253                 }
 254                 Ok(())
 255         }
 256 }
 257
 258 /// Wrapper to read elements from a given stream until it reaches the end of the stream.
 259 pub(crate) struct VecReadWrapper<T>(pub Vec<T>);
 260 impl<T: MaybeReadable> Readable for VecReadWrapper<T> {
 261         #[inline]
 262         fn read<R: Read>(mut reader: &mut R) -> Result<Self, DecodeError> {
 263                 let mut values = Vec::new();
 264                 loop {
 265                         let mut track_read = ReadTrackingReader::new(&mut reader);
 266                         match MaybeReadable::read(&mut track_read) {
 267                                 Ok(Some(v)) => { values.push(v); },
 268                                 Ok(None) => { },
 269                                 // If we failed to read any bytes at all, we reached the end of our TLV
 270                                 // stream and have simply exhausted all entries.
 271                                 Err(ref e) if e == &DecodeError::ShortRead && !track_read.have_read => break,
 272                                 Err(e) => return Err(e),
 273                         }
 274                 }
 275                 Ok(Self(values))
 276         }
 277 }
 278
 279 pub(crate) struct U48(pub u64);
 280 impl Writeable for U48 {
 281         #[inline]
 282         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 283                 writer.write_all(&be48_to_array(self.0))
 284         }
 285 }
 286 impl Readable for U48 {
 287         #[inline]
 288         fn read<R: Read>(reader: &mut R) -> Result<U48, DecodeError> {
 289                 let mut buf = [0; 6];
 290                 reader.read_exact(&mut buf)?;
 291                 Ok(U48(slice_to_be48(&buf)))
 292         }
 293 }
 294
 295 /// Lightning TLV uses a custom variable-length integer called BigSize. It is similar to Bitcoin's
 296 /// variable-length integers except that it is serialized in big-endian instead of little-endian.
 297 ///
 298 /// Like Bitcoin's variable-length integer, it exhibits ambiguity in that certain values can be
 299 /// encoded in several different ways, which we must check for at deserialization-time. Thus, if
 300 /// you're looking for an example of a variable-length integer to use for your own project, move
 301 /// along, this is a rather poor design.
 302 pub(crate) struct BigSize(pub u64);
 303 impl Writeable for BigSize {
 304         #[inline]
 305         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 306                 match self.0 {
 307                         0...0xFC => {
 308                                 (self.0 as u8).write(writer)
 309                         },
 310                         0xFD...0xFFFF => {
 311                                 0xFDu8.write(writer)?;
 312                                 (self.0 as u16).write(writer)
 313                         },
 314                         0x10000...0xFFFFFFFF => {
 315                                 0xFEu8.write(writer)?;
 316                                 (self.0 as u32).write(writer)
 317                         },
 318                         _ => {
 319                                 0xFFu8.write(writer)?;
 320                                 (self.0 as u64).write(writer)
 321                         },
 322                 }
 323         }
 324 }
 325 impl Readable for BigSize {
 326         #[inline]
 327         fn read<R: Read>(reader: &mut R) -> Result<BigSize, DecodeError> {
 328                 let n: u8 = Readable::read(reader)?;
 329                 match n {
 330                         0xFF => {
 331                                 let x: u64 = Readable::read(reader)?;
 332                                 if x < 0x100000000 {
 333                                         Err(DecodeError::InvalidValue)
 334                                 } else {
 335                                         Ok(BigSize(x))
 336                                 }
 337                         }
 338                         0xFE => {
 339                                 let x: u32 = Readable::read(reader)?;
 340                                 if x < 0x10000 {
 341                                         Err(DecodeError::InvalidValue)
 342                                 } else {
 343                                         Ok(BigSize(x as u64))
 344                                 }
 345                         }
 346                         0xFD => {
 347                                 let x: u16 = Readable::read(reader)?;
 348                                 if x < 0xFD {
 349                                         Err(DecodeError::InvalidValue)
 350                                 } else {
 351                                         Ok(BigSize(x as u64))
 352                                 }
 353                         }
 354                         n => Ok(BigSize(n as u64))
 355                 }
 356         }
 357 }
 358
 359 /// In TLV we occasionally send fields which only consist of, or potentially end with, a
 360 /// variable-length integer which is simply truncated by skipping high zero bytes. This type
 361 /// encapsulates such integers implementing Readable/Writeable for them.
 362 #[cfg_attr(test, derive(PartialEq, Debug))]
 363 pub(crate) struct HighZeroBytesDroppedVarInt<T>(pub T);
 364
 365 macro_rules! impl_writeable_primitive {
 366         ($val_type:ty, $len: expr) => {
 367                 impl Writeable for $val_type {
 368                         #[inline]
 369                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 370                                 writer.write_all(&self.to_be_bytes())
 371                         }
 372                 }
 373                 impl Writeable for HighZeroBytesDroppedVarInt<$val_type> {
 374                         #[inline]
 375                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 376                                 // Skip any full leading 0 bytes when writing (in BE):
 377                                 writer.write_all(&self.0.to_be_bytes()[(self.0.leading_zeros()/8) as usize..$len])
 378                         }
 379                 }
 380                 impl Readable for $val_type {
 381                         #[inline]
 382                         fn read<R: Read>(reader: &mut R) -> Result<$val_type, DecodeError> {
 383                                 let mut buf = [0; $len];
 384                                 reader.read_exact(&mut buf)?;
 385                                 Ok(<$val_type>::from_be_bytes(buf))
 386                         }
 387                 }
 388                 impl Readable for HighZeroBytesDroppedVarInt<$val_type> {
 389                         #[inline]
 390                         fn read<R: Read>(reader: &mut R) -> Result<HighZeroBytesDroppedVarInt<$val_type>, DecodeError> {
 391                                 // We need to accept short reads (read_len == 0) as "EOF" and handle them as simply
 392                                 // the high bytes being dropped. To do so, we start reading into the middle of buf
 393                                 // and then convert the appropriate number of bytes with extra high bytes out of
 394                                 // buf.
 395                                 let mut buf = [0; $len*2];
 396                                 let mut read_len = reader.read(&mut buf[$len..])?;
 397                                 let mut total_read_len = read_len;
 398                                 while read_len != 0 && total_read_len != $len {
 399                                         read_len = reader.read(&mut buf[($len + total_read_len)..])?;
 400                                         total_read_len += read_len;
 401                                 }
 402                                 if total_read_len == 0 || buf[$len] != 0 {
 403                                         let first_byte = $len - ($len - total_read_len);
 404                                         let mut bytes = [0; $len];
 405                                         bytes.copy_from_slice(&buf[first_byte..first_byte + $len]);
 406                                         Ok(HighZeroBytesDroppedVarInt(<$val_type>::from_be_bytes(bytes)))
 407                                 } else {
 408                                         // If the encoding had extra zero bytes, return a failure even though we know
 409                                         // what they meant (as the TLV test vectors require this)
 410                                         Err(DecodeError::InvalidValue)
 411                                 }
 412                         }
 413                 }
 414         }
 415 }
 416
 417 impl_writeable_primitive!(u64, 8);
 418 impl_writeable_primitive!(u32, 4);
 419 impl_writeable_primitive!(u16, 2);
 420
 421 impl Writeable for u8 {
 422         #[inline]
 423         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 424                 writer.write_all(&[*self])
 425         }
 426 }
 427 impl Readable for u8 {
 428         #[inline]
 429         fn read<R: Read>(reader: &mut R) -> Result<u8, DecodeError> {
 430                 let mut buf = [0; 1];
 431                 reader.read_exact(&mut buf)?;
 432                 Ok(buf[0])
 433         }
 434 }
 435
 436 impl Writeable for bool {
 437         #[inline]
 438         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 439                 writer.write_all(&[if *self {1} else {0}])
 440         }
 441 }
 442 impl Readable for bool {
 443         #[inline]
 444         fn read<R: Read>(reader: &mut R) -> Result<bool, DecodeError> {
 445                 let mut buf = [0; 1];
 446                 reader.read_exact(&mut buf)?;
 447                 if buf[0] != 0 && buf[0] != 1 {
 448                         return Err(DecodeError::InvalidValue);
 449                 }
 450                 Ok(buf[0] == 1)
 451         }
 452 }
 453
 454 // u8 arrays
 455 macro_rules! impl_array {
 456         ( $size:expr ) => (
 457                 impl Writeable for [u8; $size]
 458                 {
 459                         #[inline]
 460                         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 461                                 w.write_all(self)
 462                         }
 463                 }
 464
 465                 impl Readable for [u8; $size]
 466                 {
 467                         #[inline]
 468                         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 469                                 let mut buf = [0u8; $size];
 470                                 r.read_exact(&mut buf)?;
 471                                 Ok(buf)
 472                         }
 473                 }
 474         );
 475 }
 476
 477 //TODO: performance issue with [u8; size] with impl_array!()
 478 impl_array!(3); // for rgb
 479 impl_array!(4); // for IPv4
 480 impl_array!(10); // for OnionV2
 481 impl_array!(16); // for IPv6
 482 impl_array!(32); // for channel id & hmac
 483 impl_array!(PUBLIC_KEY_SIZE); // for PublicKey
 484 impl_array!(COMPACT_SIGNATURE_SIZE); // for Signature
 485 impl_array!(1300); // for OnionPacket.hop_data
 486
 487 // HashMap
 488 impl<K, V> Writeable for HashMap<K, V>
 489         where K: Writeable + Eq + Hash,
 490               V: Writeable
 491 {
 492         #[inline]
 493         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 494         (self.len() as u16).write(w)?;
 495                 for (key, value) in self.iter() {
 496                         key.write(w)?;
 497                         value.write(w)?;
 498                 }
 499                 Ok(())
 500         }
 501 }
 502
 503 impl<K, V> Readable for HashMap<K, V>
 504         where K: Readable + Eq + Hash,
 505               V: Readable
 506 {
 507         #[inline]
 508         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 509                 let len: u16 = Readable::read(r)?;
 510                 let mut ret = HashMap::with_capacity(len as usize);
 511                 for _ in 0..len {
 512                         ret.insert(K::read(r)?, V::read(r)?);
 513                 }
 514                 Ok(ret)
 515         }
 516 }
 517
 518 // Vectors
 519 impl Writeable for Vec<u8> {
 520         #[inline]
 521         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 522                 (self.len() as u16).write(w)?;
 523                 w.write_all(&self)
 524         }
 525 }
 526
 527 impl Readable for Vec<u8> {
 528         #[inline]
 529         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 530                 let len: u16 = Readable::read(r)?;
 531                 let mut ret = Vec::with_capacity(len as usize);
 532                 ret.resize(len as usize, 0);
 533                 r.read_exact(&mut ret)?;
 534                 Ok(ret)
 535         }
 536 }
 537 impl Writeable for Vec<Signature> {
 538         #[inline]
 539         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 540                 (self.len() as u16).write(w)?;
 541                 for e in self.iter() {
 542                         e.write(w)?;
 543                 }
 544                 Ok(())
 545         }
 546 }
 547
 548 impl Readable for Vec<Signature> {
 549         #[inline]
 550         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 551                 let len: u16 = Readable::read(r)?;
 552                 let byte_size = (len as usize)
 553                                 .checked_mul(COMPACT_SIGNATURE_SIZE)
 554                                 .ok_or(DecodeError::BadLengthDescriptor)?;
 555                 if byte_size > MAX_BUF_SIZE {
 556                         return Err(DecodeError::BadLengthDescriptor);
 557                 }
 558                 let mut ret = Vec::with_capacity(len as usize);
 559                 for _ in 0..len { ret.push(Readable::read(r)?); }
 560                 Ok(ret)
 561         }
 562 }
 563
 564 impl Writeable for Script {
 565         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 566                 (self.len() as u16).write(w)?;
 567                 w.write_all(self.as_bytes())
 568         }
 569 }
 570
 571 impl Readable for Script {
 572         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 573                 let len = <u16 as Readable>::read(r)? as usize;
 574                 let mut buf = vec![0; len];
 575                 r.read_exact(&mut buf)?;
 576                 Ok(Script::from(buf))
 577         }
 578 }
 579
 580 impl Writeable for PublicKey {
 581         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 582                 self.serialize().write(w)
 583         }
 584         #[inline]
 585         fn serialized_length(&self) -> usize {
 586                 PUBLIC_KEY_SIZE
 587         }
 588 }
 589
 590 impl Readable for PublicKey {
 591         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 592                 let buf: [u8; PUBLIC_KEY_SIZE] = Readable::read(r)?;
 593                 match PublicKey::from_slice(&buf) {
 594                         Ok(key) => Ok(key),
 595                         Err(_) => return Err(DecodeError::InvalidValue),
 596                 }
 597         }
 598 }
 599
 600 impl Writeable for SecretKey {
 601         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 602                 let mut ser = [0; SECRET_KEY_SIZE];
 603                 ser.copy_from_slice(&self[..]);
 604                 ser.write(w)
 605         }
 606         #[inline]
 607         fn serialized_length(&self) -> usize {
 608                 SECRET_KEY_SIZE
 609         }
 610 }
 611
 612 impl Readable for SecretKey {
 613         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 614                 let buf: [u8; SECRET_KEY_SIZE] = Readable::read(r)?;
 615                 match SecretKey::from_slice(&buf) {
 616                         Ok(key) => Ok(key),
 617                         Err(_) => return Err(DecodeError::InvalidValue),
 618                 }
 619         }
 620 }
 621
 622 impl Writeable for Sha256dHash {
 623         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 624                 w.write_all(&self[..])
 625         }
 626 }
 627
 628 impl Readable for Sha256dHash {
 629         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 630                 use bitcoin::hashes::Hash;
 631
 632                 let buf: [u8; 32] = Readable::read(r)?;
 633                 Ok(Sha256dHash::from_slice(&buf[..]).unwrap())
 634         }
 635 }
 636
 637 impl Writeable for Signature {
 638         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 639                 self.serialize_compact().write(w)
 640         }
 641         #[inline]
 642         fn serialized_length(&self) -> usize {
 643                 COMPACT_SIGNATURE_SIZE
 644         }
 645 }
 646
 647 impl Readable for Signature {
 648         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 649                 let buf: [u8; COMPACT_SIGNATURE_SIZE] = Readable::read(r)?;
 650                 match Signature::from_compact(&buf) {
 651                         Ok(sig) => Ok(sig),
 652                         Err(_) => return Err(DecodeError::InvalidValue),
 653                 }
 654         }
 655 }
 656
 657 impl Writeable for PaymentPreimage {
 658         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 659                 self.0.write(w)
 660         }
 661 }
 662
 663 impl Readable for PaymentPreimage {
 664         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 665                 let buf: [u8; 32] = Readable::read(r)?;
 666                 Ok(PaymentPreimage(buf))
 667         }
 668 }
 669
 670 impl Writeable for PaymentHash {
 671         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 672                 self.0.write(w)
 673         }
 674 }
 675
 676 impl Readable for PaymentHash {
 677         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 678                 let buf: [u8; 32] = Readable::read(r)?;
 679                 Ok(PaymentHash(buf))
 680         }
 681 }
 682
 683 impl Writeable for PaymentSecret {
 684         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 685                 self.0.write(w)
 686         }
 687 }
 688
 689 impl Readable for PaymentSecret {
 690         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 691                 let buf: [u8; 32] = Readable::read(r)?;
 692                 Ok(PaymentSecret(buf))
 693         }
 694 }
 695
 696 impl<T: Writeable> Writeable for Box<T> {
 697         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 698                 T::write(&**self, w)
 699         }
 700 }
 701
 702 impl<T: Readable> Readable for Box<T> {
 703         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 704                 Ok(Box::new(Readable::read(r)?))
 705         }
 706 }
 707
 708 impl<T: Writeable> Writeable for Option<T> {
 709         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 710                 match *self {
 711                         None => 0u8.write(w)?,
 712                         Some(ref data) => {
 713                                 BigSize(data.serialized_length() as u64 + 1).write(w)?;
 714                                 data.write(w)?;
 715                         }
 716                 }
 717                 Ok(())
 718         }
 719 }
 720
 721 impl<T: Readable> Readable for Option<T>
 722 {
 723         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 724                 let len: BigSize = Readable::read(r)?;
 725                 match len.0 {
 726                         0 => Ok(None),
 727                         len => {
 728                                 let mut reader = FixedLengthReader::new(r, len - 1);
 729                                 Ok(Some(Readable::read(&mut reader)?))
 730                         }
 731                 }
 732         }
 733 }
 734
 735 impl Writeable for Txid {
 736         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 737                 w.write_all(&self[..])
 738         }
 739 }
 740
 741 impl Readable for Txid {
 742         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 743                 use bitcoin::hashes::Hash;
 744
 745                 let buf: [u8; 32] = Readable::read(r)?;
 746                 Ok(Txid::from_slice(&buf[..]).unwrap())
 747         }
 748 }
 749
 750 impl Writeable for BlockHash {
 751         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 752                 w.write_all(&self[..])
 753         }
 754 }
 755
 756 impl Readable for BlockHash {
 757         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 758                 use bitcoin::hashes::Hash;
 759
 760                 let buf: [u8; 32] = Readable::read(r)?;
 761                 Ok(BlockHash::from_slice(&buf[..]).unwrap())
 762         }
 763 }
 764
 765 impl Writeable for OutPoint {
 766         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 767                 self.txid.write(w)?;
 768                 self.vout.write(w)?;
 769                 Ok(())
 770         }
 771 }
 772
 773 impl Readable for OutPoint {
 774         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 775                 let txid = Readable::read(r)?;
 776                 let vout = Readable::read(r)?;
 777                 Ok(OutPoint {
 778                         txid,
 779                         vout,
 780                 })
 781         }
 782 }
 783
 784 macro_rules! impl_consensus_ser {
 785         ($bitcoin_type: ty) => {
 786                 impl Writeable for $bitcoin_type {
 787                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 788                                 match self.consensus_encode(WriterWriteAdaptor(writer)) {
 789                                         Ok(_) => Ok(()),
 790                                         Err(e) => Err(e),
 791                                 }
 792                         }
 793                 }
 794
 795                 impl Readable for $bitcoin_type {
 796                         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 797                                 match consensus::encode::Decodable::consensus_decode(r) {
 798                                         Ok(t) => Ok(t),
 799                                         Err(consensus::encode::Error::Io(ref e)) if e.kind() == io::ErrorKind::UnexpectedEof => Err(DecodeError::ShortRead),
 800                                         Err(consensus::encode::Error::Io(e)) => Err(DecodeError::Io(e.kind())),
 801                                         Err(_) => Err(DecodeError::InvalidValue),
 802                                 }
 803                         }
 804                 }
 805         }
 806 }
 807 impl_consensus_ser!(Transaction);
 808 impl_consensus_ser!(TxOut);
 809
 810 impl<T: Readable> Readable for Mutex<T> {
 811         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 812                 let t: T = Readable::read(r)?;
 813                 Ok(Mutex::new(t))
 814         }
 815 }
 816 impl<T: Writeable> Writeable for Mutex<T> {
 817         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 818                 self.lock().unwrap().write(w)
 819         }
 820 }
 821
 822 impl<A: Readable, B: Readable> Readable for (A, B) {
 823         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 824                 let a: A = Readable::read(r)?;
 825                 let b: B = Readable::read(r)?;
 826                 Ok((a, b))
 827         }
 828 }
 829 impl<A: Writeable, B: Writeable> Writeable for (A, B) {
 830         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 831                 self.0.write(w)?;
 832                 self.1.write(w)
 833         }
 834 }
 835
 836 impl<A: Readable, B: Readable, C: Readable> Readable for (A, B, C) {
 837         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 838                 let a: A = Readable::read(r)?;
 839                 let b: B = Readable::read(r)?;
 840                 let c: C = Readable::read(r)?;
 841                 Ok((a, b, c))
 842         }
 843 }
 844 impl<A: Writeable, B: Writeable, C: Writeable> Writeable for (A, B, C) {
 845         fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
 846                 self.0.write(w)?;
 847                 self.1.write(w)?;
 848                 self.2.write(w)
 849         }
 850 }
 851
 852 impl Readable for () {
 853         fn read<R: Read>(_r: &mut R) -> Result<Self, DecodeError> {
 854                 Ok(())
 855         }
 856 }