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