_ 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 std::io::{Read, Write};
  14 use std::collections::HashMap;
  15 use std::hash::Hash;
  16 use std::sync::Mutex;
  17 use std::cmp;
  18
  19 use bitcoin::secp256k1::Signature;
  20 use bitcoin::secp256k1::key::{PublicKey, SecretKey};
  21 use bitcoin::blockdata::script::Script;
  22 use bitcoin::blockdata::transaction::{OutPoint, Transaction, TxOut};
  23 use bitcoin::consensus;
  24 use bitcoin::consensus::Encodable;
  25 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
  26 use bitcoin::hash_types::{Txid, BlockHash};
  27 use std::marker::Sized;
  28 use ln::msgs::DecodeError;
  29 use ln::channelmanager::{PaymentPreimage, PaymentHash, PaymentSecret};
  30 use util::byte_utils;
  31
  32 use util::byte_utils::{be64_to_array, be48_to_array, be32_to_array, be16_to_array, slice_to_be16, slice_to_be32, slice_to_be48, slice_to_be64};
  33
  34 const MAX_BUF_SIZE: usize = 64 * 1024;
  35
  36 /// A trait that is similar to std::io::Write but has one extra function which can be used to size
  37 /// buffers being written into.
  38 /// An impl is provided for any type that also impls std::io::Write which simply ignores size
  39 /// hints.
  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<(), ::std::io::Error>;
  45         /// Hints that data of the given size is about the be written. This may not always be called
  46         /// prior to data being written and may be safely ignored.
  47         fn size_hint(&mut self, size: usize);
  48 }
  49
  50 impl<W: Write> Writer for W {
  51         #[inline]
  52         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  53                 <Self as ::std::io::Write>::write_all(self, buf)
  54         }
  55         #[inline]
  56         fn size_hint(&mut self, _size: usize) { }
  57 }
  58
  59 pub(crate) struct WriterWriteAdaptor<'a, W: Writer + 'a>(pub &'a mut W);
  60 impl<'a, W: Writer + 'a> Write for WriterWriteAdaptor<'a, W> {
  61         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  62                 self.0.write_all(buf)
  63         }
  64         fn write(&mut self, buf: &[u8]) -> Result<usize, ::std::io::Error> {
  65                 self.0.write_all(buf)?;
  66                 Ok(buf.len())
  67         }
  68         fn flush(&mut self) -> Result<(), ::std::io::Error> {
  69                 Ok(())
  70         }
  71 }
  72
  73 pub(crate) struct VecWriter(pub Vec<u8>);
  74 impl Writer for VecWriter {
  75         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  76                 self.0.extend_from_slice(buf);
  77                 Ok(())
  78         }
  79         fn size_hint(&mut self, size: usize) {
  80                 self.0.reserve_exact(size);
  81         }
  82 }
  83
  84 /// Writer that only tracks the amount of data written - useful if you need to calculate the length
  85 /// of some data when serialized but don't yet need the full data.
  86 pub(crate) struct LengthCalculatingWriter(pub usize);
  87 impl Writer for LengthCalculatingWriter {
  88         #[inline]
  89         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  90                 self.0 += buf.len();
  91                 Ok(())
  92         }
  93         #[inline]
  94         fn size_hint(&mut self, _size: usize) {}
  95 }
  96
  97 /// Essentially std::io::Take but a bit simpler and with a method to walk the underlying stream
  98 /// forward to ensure we always consume exactly the fixed length specified.
  99 pub(crate) struct FixedLengthReader<R: Read> {
 100         read: R,
 101         bytes_read: u64,
 102         total_bytes: u64,
 103 }
 104 impl<R: Read> FixedLengthReader<R> {
 105         pub fn new(read: R, total_bytes: u64) -> Self {
 106                 Self { read, bytes_read: 0, total_bytes }
 107         }
 108
 109         pub fn bytes_remain(&mut self) -> bool {
 110                 self.bytes_read != self.total_bytes
 111         }
 112
 113         pub fn eat_remaining(&mut self) -> Result<(), DecodeError> {
 114                 ::std::io::copy(self, &mut ::std::io::sink()).unwrap();
 115                 if self.bytes_read != self.total_bytes {
 116                         Err(DecodeError::ShortRead)
 117                 } else {
 118                         Ok(())
 119                 }
 120         }
 121 }
 122 impl<R: Read> Read for FixedLengthReader<R> {
 123         fn read(&mut self, dest: &mut [u8]) -> Result<usize, ::std::io::Error> {
 124                 if self.total_bytes == self.bytes_read {
 125                         Ok(0)
 126                 } else {
 127                         let read_len = cmp::min(dest.len() as u64, self.total_bytes - self.bytes_read);
 128                         match self.read.read(&mut dest[0..(read_len as usize)]) {
 129                                 Ok(v) => {
 130                                         self.bytes_read += v as u64;
 131                                         Ok(v)
 132                                 },
 133                                 Err(e) => Err(e),
 134                         }
 135                 }
 136         }
 137 }
 138
 139 /// A Read which tracks whether any bytes have been read at all. This allows us to distinguish
 140 /// between "EOF reached before we started" and "EOF reached mid-read".
 141 pub(crate) struct ReadTrackingReader<R: Read> {
 142         read: R,
 143         pub have_read: bool,
 144 }
 145 impl<R: Read> ReadTrackingReader<R> {
 146         pub fn new(read: R) -> Self {
 147                 Self { read, have_read: false }
 148         }
 149 }
 150 impl<R: Read> Read for ReadTrackingReader<R> {
 151         fn read(&mut self, dest: &mut [u8]) -> Result<usize, ::std::io::Error> {
 152                 match self.read.read(dest) {
 153                         Ok(0) => Ok(0),
 154                         Ok(len) => {
 155                                 self.have_read = true;
 156                                 Ok(len)
 157                         },
 158                         Err(e) => Err(e),
 159                 }
 160         }
 161 }
 162
 163 /// A trait that various rust-lightning types implement allowing them to be written out to a Writer
 164 ///
 165 /// (C-not exported) as we only export serialization to/from byte arrays instead
 166 pub trait Writeable {
 167         /// Writes self out to the given Writer
 168         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error>;
 169
 170         /// Writes self out to a Vec<u8>
 171         fn encode(&self) -> Vec<u8> {
 172                 let mut msg = VecWriter(Vec::new());
 173                 self.write(&mut msg).unwrap();
 174                 msg.0
 175         }
 176
 177         /// Writes self out to a Vec<u8>
 178         fn encode_with_len(&self) -> Vec<u8> {
 179                 let mut msg = VecWriter(Vec::new());
 180                 0u16.write(&mut msg).unwrap();
 181                 self.write(&mut msg).unwrap();
 182                 let len = msg.0.len();
 183                 msg.0[..2].copy_from_slice(&byte_utils::be16_to_array(len as u16 - 2));
 184                 msg.0
 185         }
 186 }
 187
 188 impl<'a, T: Writeable> Writeable for &'a T {
 189         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> { (*self).write(writer) }
 190 }
 191
 192 /// A trait that various rust-lightning types implement allowing them to be read in from a Read
 193 ///
 194 /// (C-not exported) as we only export serialization to/from byte arrays instead
 195 pub trait Readable
 196         where Self: Sized
 197 {
 198         /// Reads a Self in from the given Read
 199         fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError>;
 200 }
 201
 202 /// A trait that various higher-level rust-lightning types implement allowing them to be read in
 203 /// from a Read given some additional set of arguments which is required to deserialize.
 204 ///
 205 /// (C-not exported) as we only export serialization to/from byte arrays instead
 206 pub trait ReadableArgs<P>
 207         where Self: Sized
 208 {
 209         /// Reads a Self in from the given Read
 210         fn read<R: Read>(reader: &mut R, params: P) -> Result<Self, DecodeError>;
 211 }
 212
 213 /// A trait that various rust-lightning types implement allowing them to (maybe) be read in from a Read
 214 ///
 215 /// (C-not exported) as we only export serialization to/from byte arrays instead
 216 pub trait MaybeReadable
 217         where Self: Sized
 218 {
 219         /// Reads a Self in from the given Read
 220         fn read<R: Read>(reader: &mut R) -> Result<Option<Self>, DecodeError>;
 221 }
 222
 223 pub(crate) struct U48(pub u64);
 224 impl Writeable for U48 {
 225         #[inline]
 226         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 227                 writer.write_all(&be48_to_array(self.0))
 228         }
 229 }
 230 impl Readable for U48 {
 231         #[inline]
 232         fn read<R: Read>(reader: &mut R) -> Result<U48, DecodeError> {
 233                 let mut buf = [0; 6];
 234                 reader.read_exact(&mut buf)?;
 235                 Ok(U48(slice_to_be48(&buf)))
 236         }
 237 }
 238
 239 /// Lightning TLV uses a custom variable-length integer called BigSize. It is similar to Bitcoin's
 240 /// variable-length integers except that it is serialized in big-endian instead of little-endian.
 241 ///
 242 /// Like Bitcoin's variable-length integer, it exhibits ambiguity in that certain values can be
 243 /// encoded in several different ways, which we must check for at deserialization-time. Thus, if
 244 /// you're looking for an example of a variable-length integer to use for your own project, move
 245 /// along, this is a rather poor design.
 246 pub(crate) struct BigSize(pub u64);
 247 impl Writeable for BigSize {
 248         #[inline]
 249         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 250                 match self.0 {
 251                         0...0xFC => {
 252                                 (self.0 as u8).write(writer)
 253                         },
 254                         0xFD...0xFFFF => {
 255                                 0xFDu8.write(writer)?;
 256                                 (self.0 as u16).write(writer)
 257                         },
 258                         0x10000...0xFFFFFFFF => {
 259                                 0xFEu8.write(writer)?;
 260                                 (self.0 as u32).write(writer)
 261                         },
 262                         _ => {
 263                                 0xFFu8.write(writer)?;
 264                                 (self.0 as u64).write(writer)
 265                         },
 266                 }
 267         }
 268 }
 269 impl Readable for BigSize {
 270         #[inline]
 271         fn read<R: Read>(reader: &mut R) -> Result<BigSize, DecodeError> {
 272                 let n: u8 = Readable::read(reader)?;
 273                 match n {
 274                         0xFF => {
 275                                 let x: u64 = Readable::read(reader)?;
 276                                 if x < 0x100000000 {
 277                                         Err(DecodeError::InvalidValue)
 278                                 } else {
 279                                         Ok(BigSize(x))
 280                                 }
 281                         }
 282                         0xFE => {
 283                                 let x: u32 = Readable::read(reader)?;
 284                                 if x < 0x10000 {
 285                                         Err(DecodeError::InvalidValue)
 286                                 } else {
 287                                         Ok(BigSize(x as u64))
 288                                 }
 289                         }
 290                         0xFD => {
 291                                 let x: u16 = Readable::read(reader)?;
 292                                 if x < 0xFD {
 293                                         Err(DecodeError::InvalidValue)
 294                                 } else {
 295                                         Ok(BigSize(x as u64))
 296                                 }
 297                         }
 298                         n => Ok(BigSize(n as u64))
 299                 }
 300         }
 301 }
 302
 303 /// In TLV we occasionally send fields which only consist of, or potentially end with, a
 304 /// variable-length integer which is simply truncated by skipping high zero bytes. This type
 305 /// encapsulates such integers implementing Readable/Writeable for them.
 306 #[cfg_attr(test, derive(PartialEq, Debug))]
 307 pub(crate) struct HighZeroBytesDroppedVarInt<T>(pub T);
 308
 309 macro_rules! impl_writeable_primitive {
 310         ($val_type:ty, $meth_write:ident, $len: expr, $meth_read:ident) => {
 311                 impl Writeable for $val_type {
 312                         #[inline]
 313                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 314                                 writer.write_all(&$meth_write(*self))
 315                         }
 316                 }
 317                 impl Writeable for HighZeroBytesDroppedVarInt<$val_type> {
 318                         #[inline]
 319                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 320                                 // Skip any full leading 0 bytes when writing (in BE):
 321                                 writer.write_all(&$meth_write(self.0)[(self.0.leading_zeros()/8) as usize..$len])
 322                         }
 323                 }
 324                 impl Readable for $val_type {
 325                         #[inline]
 326                         fn read<R: Read>(reader: &mut R) -> Result<$val_type, DecodeError> {
 327                                 let mut buf = [0; $len];
 328                                 reader.read_exact(&mut buf)?;
 329                                 Ok($meth_read(&buf))
 330                         }
 331                 }
 332                 impl Readable for HighZeroBytesDroppedVarInt<$val_type> {
 333                         #[inline]
 334                         fn read<R: Read>(reader: &mut R) -> Result<HighZeroBytesDroppedVarInt<$val_type>, DecodeError> {
 335                                 // We need to accept short reads (read_len == 0) as "EOF" and handle them as simply
 336                                 // the high bytes being dropped. To do so, we start reading into the middle of buf
 337                                 // and then convert the appropriate number of bytes with extra high bytes out of
 338                                 // buf.
 339                                 let mut buf = [0; $len*2];
 340                                 let mut read_len = reader.read(&mut buf[$len..])?;
 341                                 let mut total_read_len = read_len;
 342                                 while read_len != 0 && total_read_len != $len {
 343                                         read_len = reader.read(&mut buf[($len + total_read_len)..])?;
 344                                         total_read_len += read_len;
 345                                 }
 346                                 if total_read_len == 0 || buf[$len] != 0 {
 347                                         let first_byte = $len - ($len - total_read_len);
 348                                         Ok(HighZeroBytesDroppedVarInt($meth_read(&buf[first_byte..first_byte + $len])))
 349                                 } else {
 350                                         // If the encoding had extra zero bytes, return a failure even though we know
 351                                         // what they meant (as the TLV test vectors require this)
 352                                         Err(DecodeError::InvalidValue)
 353                                 }
 354                         }
 355                 }
 356         }
 357 }
 358
 359 impl_writeable_primitive!(u64, be64_to_array, 8, slice_to_be64);
 360 impl_writeable_primitive!(u32, be32_to_array, 4, slice_to_be32);
 361 impl_writeable_primitive!(u16, be16_to_array, 2, slice_to_be16);
 362
 363 impl Writeable for u8 {
 364         #[inline]
 365         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 366                 writer.write_all(&[*self])
 367         }
 368 }
 369 impl Readable for u8 {
 370         #[inline]
 371         fn read<R: Read>(reader: &mut R) -> Result<u8, DecodeError> {
 372                 let mut buf = [0; 1];
 373                 reader.read_exact(&mut buf)?;
 374                 Ok(buf[0])
 375         }
 376 }
 377
 378 impl Writeable for bool {
 379         #[inline]
 380         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 381                 writer.write_all(&[if *self {1} else {0}])
 382         }
 383 }
 384 impl Readable for bool {
 385         #[inline]
 386         fn read<R: Read>(reader: &mut R) -> Result<bool, DecodeError> {
 387                 let mut buf = [0; 1];
 388                 reader.read_exact(&mut buf)?;
 389                 if buf[0] != 0 && buf[0] != 1 {
 390                         return Err(DecodeError::InvalidValue);
 391                 }
 392                 Ok(buf[0] == 1)
 393         }
 394 }
 395
 396 // u8 arrays
 397 macro_rules! impl_array {
 398         ( $size:expr ) => (
 399                 impl Writeable for [u8; $size]
 400                 {
 401                         #[inline]
 402                         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 403                                 w.write_all(self)
 404                         }
 405                 }
 406
 407                 impl Readable for [u8; $size]
 408                 {
 409                         #[inline]
 410                         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 411                                 let mut buf = [0u8; $size];
 412                                 r.read_exact(&mut buf)?;
 413                                 Ok(buf)
 414                         }
 415                 }
 416         );
 417 }
 418
 419 //TODO: performance issue with [u8; size] with impl_array!()
 420 impl_array!(3); // for rgb
 421 impl_array!(4); // for IPv4
 422 impl_array!(10); // for OnionV2
 423 impl_array!(16); // for IPv6
 424 impl_array!(32); // for channel id & hmac
 425 impl_array!(33); // for PublicKey
 426 impl_array!(64); // for Signature
 427 impl_array!(1300); // for OnionPacket.hop_data
 428
 429 // HashMap
 430 impl<K, V> Writeable for HashMap<K, V>
 431         where K: Writeable + Eq + Hash,
 432               V: Writeable
 433 {
 434         #[inline]
 435         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 436         (self.len() as u16).write(w)?;
 437                 for (key, value) in self.iter() {
 438                         key.write(w)?;
 439                         value.write(w)?;
 440                 }
 441                 Ok(())
 442         }
 443 }
 444
 445 impl<K, V> Readable for HashMap<K, V>
 446         where K: Readable + Eq + Hash,
 447               V: Readable
 448 {
 449         #[inline]
 450         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 451                 let len: u16 = Readable::read(r)?;
 452                 let mut ret = HashMap::with_capacity(len as usize);
 453                 for _ in 0..len {
 454                         ret.insert(K::read(r)?, V::read(r)?);
 455                 }
 456                 Ok(ret)
 457         }
 458 }
 459
 460 // Vectors
 461 impl Writeable for Vec<u8> {
 462         #[inline]
 463         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 464                 (self.len() as u16).write(w)?;
 465                 w.write_all(&self)
 466         }
 467 }
 468
 469 impl Readable for Vec<u8> {
 470         #[inline]
 471         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 472                 let len: u16 = Readable::read(r)?;
 473                 let mut ret = Vec::with_capacity(len as usize);
 474                 ret.resize(len as usize, 0);
 475                 r.read_exact(&mut ret)?;
 476                 Ok(ret)
 477         }
 478 }
 479 impl Writeable for Vec<Signature> {
 480         #[inline]
 481         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 482                 (self.len() as u16).write(w)?;
 483                 for e in self.iter() {
 484                         e.write(w)?;
 485                 }
 486                 Ok(())
 487         }
 488 }
 489
 490 impl Readable for Vec<Signature> {
 491         #[inline]
 492         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 493                 let len: u16 = Readable::read(r)?;
 494                 let byte_size = (len as usize)
 495                                 .checked_mul(33)
 496                                 .ok_or(DecodeError::BadLengthDescriptor)?;
 497                 if byte_size > MAX_BUF_SIZE {
 498                         return Err(DecodeError::BadLengthDescriptor);
 499                 }
 500                 let mut ret = Vec::with_capacity(len as usize);
 501                 for _ in 0..len { ret.push(Signature::read(r)?); }
 502                 Ok(ret)
 503         }
 504 }
 505
 506 impl Writeable for Script {
 507         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 508                 (self.len() as u16).write(w)?;
 509                 w.write_all(self.as_bytes())
 510         }
 511 }
 512
 513 impl Readable for Script {
 514         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 515                 let len = <u16 as Readable>::read(r)? as usize;
 516                 let mut buf = vec![0; len];
 517                 r.read_exact(&mut buf)?;
 518                 Ok(Script::from(buf))
 519         }
 520 }
 521
 522 impl Writeable for PublicKey {
 523         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 524                 self.serialize().write(w)
 525         }
 526 }
 527
 528 impl Readable for PublicKey {
 529         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 530                 let buf: [u8; 33] = Readable::read(r)?;
 531                 match PublicKey::from_slice(&buf) {
 532                         Ok(key) => Ok(key),
 533                         Err(_) => return Err(DecodeError::InvalidValue),
 534                 }
 535         }
 536 }
 537
 538 impl Writeable for SecretKey {
 539         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 540                 let mut ser = [0; 32];
 541                 ser.copy_from_slice(&self[..]);
 542                 ser.write(w)
 543         }
 544 }
 545
 546 impl Readable for SecretKey {
 547         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 548                 let buf: [u8; 32] = Readable::read(r)?;
 549                 match SecretKey::from_slice(&buf) {
 550                         Ok(key) => Ok(key),
 551                         Err(_) => return Err(DecodeError::InvalidValue),
 552                 }
 553         }
 554 }
 555
 556 impl Writeable for Sha256dHash {
 557         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 558                 w.write_all(&self[..])
 559         }
 560 }
 561
 562 impl Readable for Sha256dHash {
 563         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 564                 use bitcoin::hashes::Hash;
 565
 566                 let buf: [u8; 32] = Readable::read(r)?;
 567                 Ok(Sha256dHash::from_slice(&buf[..]).unwrap())
 568         }
 569 }
 570
 571 impl Writeable for Signature {
 572         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 573                 self.serialize_compact().write(w)
 574         }
 575 }
 576
 577 impl Readable for Signature {
 578         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 579                 let buf: [u8; 64] = Readable::read(r)?;
 580                 match Signature::from_compact(&buf) {
 581                         Ok(sig) => Ok(sig),
 582                         Err(_) => return Err(DecodeError::InvalidValue),
 583                 }
 584         }
 585 }
 586
 587 impl Writeable for PaymentPreimage {
 588         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 589                 self.0.write(w)
 590         }
 591 }
 592
 593 impl Readable for PaymentPreimage {
 594         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 595                 let buf: [u8; 32] = Readable::read(r)?;
 596                 Ok(PaymentPreimage(buf))
 597         }
 598 }
 599
 600 impl Writeable for PaymentHash {
 601         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 602                 self.0.write(w)
 603         }
 604 }
 605
 606 impl Readable for PaymentHash {
 607         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 608                 let buf: [u8; 32] = Readable::read(r)?;
 609                 Ok(PaymentHash(buf))
 610         }
 611 }
 612
 613 impl Writeable for PaymentSecret {
 614         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 615                 self.0.write(w)
 616         }
 617 }
 618
 619 impl Readable for PaymentSecret {
 620         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 621                 let buf: [u8; 32] = Readable::read(r)?;
 622                 Ok(PaymentSecret(buf))
 623         }
 624 }
 625
 626 impl<T: Writeable> Writeable for Option<T> {
 627         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 628                 match *self {
 629                         None => 0u8.write(w)?,
 630                         Some(ref data) => {
 631                                 let mut len_calc = LengthCalculatingWriter(0);
 632                                 data.write(&mut len_calc).expect("No in-memory data may fail to serialize");
 633                                 BigSize(len_calc.0 as u64 + 1).write(w)?;
 634                                 data.write(w)?;
 635                         }
 636                 }
 637                 Ok(())
 638         }
 639 }
 640
 641 impl<T: Readable> Readable for Option<T>
 642 {
 643         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 644                 match BigSize::read(r)?.0 {
 645                         0 => Ok(None),
 646                         len => {
 647                                 let mut reader = FixedLengthReader::new(r, len - 1);
 648                                 Ok(Some(Readable::read(&mut reader)?))
 649                         }
 650                 }
 651         }
 652 }
 653
 654 impl Writeable for Txid {
 655         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 656                 w.write_all(&self[..])
 657         }
 658 }
 659
 660 impl Readable for Txid {
 661         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 662                 use bitcoin::hashes::Hash;
 663
 664                 let buf: [u8; 32] = Readable::read(r)?;
 665                 Ok(Txid::from_slice(&buf[..]).unwrap())
 666         }
 667 }
 668
 669 impl Writeable for BlockHash {
 670         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 671                 w.write_all(&self[..])
 672         }
 673 }
 674
 675 impl Readable for BlockHash {
 676         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 677                 use bitcoin::hashes::Hash;
 678
 679                 let buf: [u8; 32] = Readable::read(r)?;
 680                 Ok(BlockHash::from_slice(&buf[..]).unwrap())
 681         }
 682 }
 683
 684 impl Writeable for OutPoint {
 685         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 686                 self.txid.write(w)?;
 687                 self.vout.write(w)?;
 688                 Ok(())
 689         }
 690 }
 691
 692 impl Readable for OutPoint {
 693         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 694                 let txid = Readable::read(r)?;
 695                 let vout = Readable::read(r)?;
 696                 Ok(OutPoint {
 697                         txid,
 698                         vout,
 699                 })
 700         }
 701 }
 702
 703 macro_rules! impl_consensus_ser {
 704         ($bitcoin_type: ty) => {
 705                 impl Writeable for $bitcoin_type {
 706                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 707                                 match self.consensus_encode(WriterWriteAdaptor(writer)) {
 708                                         Ok(_) => Ok(()),
 709                                         Err(consensus::encode::Error::Io(e)) => Err(e),
 710                                         Err(_) => panic!("We shouldn't get a consensus::encode::Error unless our Write generated an std::io::Error"),
 711                                 }
 712                         }
 713                 }
 714
 715                 impl Readable for $bitcoin_type {
 716                         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 717                                 match consensus::encode::Decodable::consensus_decode(r) {
 718                                         Ok(t) => Ok(t),
 719                                         Err(consensus::encode::Error::Io(ref e)) if e.kind() == ::std::io::ErrorKind::UnexpectedEof => Err(DecodeError::ShortRead),
 720                                         Err(consensus::encode::Error::Io(e)) => Err(DecodeError::Io(e)),
 721                                         Err(_) => Err(DecodeError::InvalidValue),
 722                                 }
 723                         }
 724                 }
 725         }
 726 }
 727 impl_consensus_ser!(Transaction);
 728 impl_consensus_ser!(TxOut);
 729
 730 impl<T: Readable> Readable for Mutex<T> {
 731         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 732                 let t: T = Readable::read(r)?;
 733                 Ok(Mutex::new(t))
 734         }
 735 }
 736 impl<T: Writeable> Writeable for Mutex<T> {
 737         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 738                 self.lock().unwrap().write(w)
 739         }
 740 }
 741
 742 impl<A: Readable, B: Readable> Readable for (A, B) {
 743         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 744                 let a: A = Readable::read(r)?;
 745                 let b: B = Readable::read(r)?;
 746                 Ok((a, b))
 747         }
 748 }
 749 impl<A: Writeable, B: Writeable> Writeable for (A, B) {
 750         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 751                 self.0.write(w)?;
 752                 self.1.write(w)
 753         }
 754 }