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

   1 //! A very simple serialization framework which is used to serialize/deserialize messages as well
   2 //! as ChannelsManagers and ChannelMonitors.
   3
   4 use std::result::Result;
   5 use std::io::{Read, Write};
   6 use std::collections::HashMap;
   7 use std::hash::Hash;
   8 use std::sync::Mutex;
   9 use std::cmp;
  10
  11 use bitcoin::secp256k1::Signature;
  12 use bitcoin::secp256k1::key::{PublicKey, SecretKey};
  13 use bitcoin::blockdata::script::Script;
  14 use bitcoin::blockdata::transaction::{OutPoint, Transaction, TxOut};
  15 use bitcoin::consensus;
  16 use bitcoin::consensus::Encodable;
  17 use bitcoin::hashes::sha256d::Hash as Sha256dHash;
  18 use std::marker::Sized;
  19 use ln::msgs::DecodeError;
  20 use ln::channelmanager::{PaymentPreimage, PaymentHash, PaymentSecret};
  21 use util::byte_utils;
  22
  23 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};
  24
  25 const MAX_BUF_SIZE: usize = 64 * 1024;
  26
  27 /// A trait that is similar to std::io::Write but has one extra function which can be used to size
  28 /// buffers being written into.
  29 /// An impl is provided for any type that also impls std::io::Write which simply ignores size
  30 /// hints.
  31 pub trait Writer {
  32         /// Writes the given buf out. See std::io::Write::write_all for more
  33         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error>;
  34         /// Hints that data of the given size is about the be written. This may not always be called
  35         /// prior to data being written and may be safely ignored.
  36         fn size_hint(&mut self, size: usize);
  37 }
  38
  39 impl<W: Write> Writer for W {
  40         #[inline]
  41         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  42                 <Self as ::std::io::Write>::write_all(self, buf)
  43         }
  44         #[inline]
  45         fn size_hint(&mut self, _size: usize) { }
  46 }
  47
  48 pub(crate) struct WriterWriteAdaptor<'a, W: Writer + 'a>(pub &'a mut W);
  49 impl<'a, W: Writer + 'a> Write for WriterWriteAdaptor<'a, W> {
  50         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  51                 self.0.write_all(buf)
  52         }
  53         fn write(&mut self, buf: &[u8]) -> Result<usize, ::std::io::Error> {
  54                 self.0.write_all(buf)?;
  55                 Ok(buf.len())
  56         }
  57         fn flush(&mut self) -> Result<(), ::std::io::Error> {
  58                 Ok(())
  59         }
  60 }
  61
  62 pub(crate) struct VecWriter(pub Vec<u8>);
  63 impl Writer for VecWriter {
  64         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  65                 self.0.extend_from_slice(buf);
  66                 Ok(())
  67         }
  68         fn size_hint(&mut self, size: usize) {
  69                 self.0.reserve_exact(size);
  70         }
  71 }
  72
  73 /// Writer that only tracks the amount of data written - useful if you need to calculate the length
  74 /// of some data when serialized but don't yet need the full data.
  75 pub(crate) struct LengthCalculatingWriter(pub usize);
  76 impl Writer for LengthCalculatingWriter {
  77         #[inline]
  78         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  79                 self.0 += buf.len();
  80                 Ok(())
  81         }
  82         #[inline]
  83         fn size_hint(&mut self, _size: usize) {}
  84 }
  85
  86 /// Essentially std::io::Take but a bit simpler and with a method to walk the underlying stream
  87 /// forward to ensure we always consume exactly the fixed length specified.
  88 pub(crate) struct FixedLengthReader<R: Read> {
  89         read: R,
  90         bytes_read: u64,
  91         total_bytes: u64,
  92 }
  93 impl<R: Read> FixedLengthReader<R> {
  94         pub fn new(read: R, total_bytes: u64) -> Self {
  95                 Self { read, bytes_read: 0, total_bytes }
  96         }
  97
  98         pub fn bytes_remain(&mut self) -> bool {
  99                 self.bytes_read != self.total_bytes
 100         }
 101
 102         pub fn eat_remaining(&mut self) -> Result<(), DecodeError> {
 103                 ::std::io::copy(self, &mut ::std::io::sink()).unwrap();
 104                 if self.bytes_read != self.total_bytes {
 105                         Err(DecodeError::ShortRead)
 106                 } else {
 107                         Ok(())
 108                 }
 109         }
 110 }
 111 impl<R: Read> Read for FixedLengthReader<R> {
 112         fn read(&mut self, dest: &mut [u8]) -> Result<usize, ::std::io::Error> {
 113                 if self.total_bytes == self.bytes_read {
 114                         Ok(0)
 115                 } else {
 116                         let read_len = cmp::min(dest.len() as u64, self.total_bytes - self.bytes_read);
 117                         match self.read.read(&mut dest[0..(read_len as usize)]) {
 118                                 Ok(v) => {
 119                                         self.bytes_read += v as u64;
 120                                         Ok(v)
 121                                 },
 122                                 Err(e) => Err(e),
 123                         }
 124                 }
 125         }
 126 }
 127
 128 /// A Read which tracks whether any bytes have been read at all. This allows us to distinguish
 129 /// between "EOF reached before we started" and "EOF reached mid-read".
 130 pub(crate) struct ReadTrackingReader<R: Read> {
 131         read: R,
 132         pub have_read: bool,
 133 }
 134 impl<R: Read> ReadTrackingReader<R> {
 135         pub fn new(read: R) -> Self {
 136                 Self { read, have_read: false }
 137         }
 138 }
 139 impl<R: Read> Read for ReadTrackingReader<R> {
 140         fn read(&mut self, dest: &mut [u8]) -> Result<usize, ::std::io::Error> {
 141                 match self.read.read(dest) {
 142                         Ok(0) => Ok(0),
 143                         Ok(len) => {
 144                                 self.have_read = true;
 145                                 Ok(len)
 146                         },
 147                         Err(e) => Err(e),
 148                 }
 149         }
 150 }
 151
 152 /// A trait that various rust-lightning types implement allowing them to be written out to a Writer
 153 pub trait Writeable {
 154         /// Writes self out to the given Writer
 155         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error>;
 156
 157         /// Writes self out to a Vec<u8>
 158         fn encode(&self) -> Vec<u8> {
 159                 let mut msg = VecWriter(Vec::new());
 160                 self.write(&mut msg).unwrap();
 161                 msg.0
 162         }
 163
 164         /// Writes self out to a Vec<u8>
 165         fn encode_with_len(&self) -> Vec<u8> {
 166                 let mut msg = VecWriter(Vec::new());
 167                 0u16.write(&mut msg).unwrap();
 168                 self.write(&mut msg).unwrap();
 169                 let len = msg.0.len();
 170                 msg.0[..2].copy_from_slice(&byte_utils::be16_to_array(len as u16 - 2));
 171                 msg.0
 172         }
 173 }
 174
 175 impl<'a, T: Writeable> Writeable for &'a T {
 176         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> { (*self).write(writer) }
 177 }
 178
 179 /// A trait that various rust-lightning types implement allowing them to be read in from a Read
 180 pub trait Readable
 181         where Self: Sized
 182 {
 183         /// Reads a Self in from the given Read
 184         fn read<R: Read>(reader: &mut R) -> Result<Self, DecodeError>;
 185 }
 186
 187 /// A trait that various higher-level rust-lightning types implement allowing them to be read in
 188 /// from a Read given some additional set of arguments which is required to deserialize.
 189 pub trait ReadableArgs<P>
 190         where Self: Sized
 191 {
 192         /// Reads a Self in from the given Read
 193         fn read<R: Read>(reader: &mut R, params: P) -> Result<Self, DecodeError>;
 194 }
 195
 196 /// A trait that various rust-lightning types implement allowing them to (maybe) be read in from a Read
 197 pub trait MaybeReadable
 198         where Self: Sized
 199 {
 200         /// Reads a Self in from the given Read
 201         fn read<R: Read>(reader: &mut R) -> Result<Option<Self>, DecodeError>;
 202 }
 203
 204 pub(crate) struct U48(pub u64);
 205 impl Writeable for U48 {
 206         #[inline]
 207         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 208                 writer.write_all(&be48_to_array(self.0))
 209         }
 210 }
 211 impl Readable for U48 {
 212         #[inline]
 213         fn read<R: Read>(reader: &mut R) -> Result<U48, DecodeError> {
 214                 let mut buf = [0; 6];
 215                 reader.read_exact(&mut buf)?;
 216                 Ok(U48(slice_to_be48(&buf)))
 217         }
 218 }
 219
 220 /// Lightning TLV uses a custom variable-length integer called BigSize. It is similar to Bitcoin's
 221 /// variable-length integers except that it is serialized in big-endian instead of little-endian.
 222 ///
 223 /// Like Bitcoin's variable-length integer, it exhibits ambiguity in that certain values can be
 224 /// encoded in several different ways, which we must check for at deserialization-time. Thus, if
 225 /// you're looking for an example of a variable-length integer to use for your own project, move
 226 /// along, this is a rather poor design.
 227 pub(crate) struct BigSize(pub u64);
 228 impl Writeable for BigSize {
 229         #[inline]
 230         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 231                 match self.0 {
 232                         0...0xFC => {
 233                                 (self.0 as u8).write(writer)
 234                         },
 235                         0xFD...0xFFFF => {
 236                                 0xFDu8.write(writer)?;
 237                                 (self.0 as u16).write(writer)
 238                         },
 239                         0x10000...0xFFFFFFFF => {
 240                                 0xFEu8.write(writer)?;
 241                                 (self.0 as u32).write(writer)
 242                         },
 243                         _ => {
 244                                 0xFFu8.write(writer)?;
 245                                 (self.0 as u64).write(writer)
 246                         },
 247                 }
 248         }
 249 }
 250 impl Readable for BigSize {
 251         #[inline]
 252         fn read<R: Read>(reader: &mut R) -> Result<BigSize, DecodeError> {
 253                 let n: u8 = Readable::read(reader)?;
 254                 match n {
 255                         0xFF => {
 256                                 let x: u64 = Readable::read(reader)?;
 257                                 if x < 0x100000000 {
 258                                         Err(DecodeError::InvalidValue)
 259                                 } else {
 260                                         Ok(BigSize(x))
 261                                 }
 262                         }
 263                         0xFE => {
 264                                 let x: u32 = Readable::read(reader)?;
 265                                 if x < 0x10000 {
 266                                         Err(DecodeError::InvalidValue)
 267                                 } else {
 268                                         Ok(BigSize(x as u64))
 269                                 }
 270                         }
 271                         0xFD => {
 272                                 let x: u16 = Readable::read(reader)?;
 273                                 if x < 0xFD {
 274                                         Err(DecodeError::InvalidValue)
 275                                 } else {
 276                                         Ok(BigSize(x as u64))
 277                                 }
 278                         }
 279                         n => Ok(BigSize(n as u64))
 280                 }
 281         }
 282 }
 283
 284 /// In TLV we occasionally send fields which only consist of, or potentially end with, a
 285 /// variable-length integer which is simply truncated by skipping high zero bytes. This type
 286 /// encapsulates such integers implementing Readable/Writeable for them.
 287 #[cfg_attr(test, derive(PartialEq, Debug))]
 288 pub(crate) struct HighZeroBytesDroppedVarInt<T>(pub T);
 289
 290 macro_rules! impl_writeable_primitive {
 291         ($val_type:ty, $meth_write:ident, $len: expr, $meth_read:ident) => {
 292                 impl Writeable for $val_type {
 293                         #[inline]
 294                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 295                                 writer.write_all(&$meth_write(*self))
 296                         }
 297                 }
 298                 impl Writeable for HighZeroBytesDroppedVarInt<$val_type> {
 299                         #[inline]
 300                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 301                                 // Skip any full leading 0 bytes when writing (in BE):
 302                                 writer.write_all(&$meth_write(self.0)[(self.0.leading_zeros()/8) as usize..$len])
 303                         }
 304                 }
 305                 impl Readable for $val_type {
 306                         #[inline]
 307                         fn read<R: Read>(reader: &mut R) -> Result<$val_type, DecodeError> {
 308                                 let mut buf = [0; $len];
 309                                 reader.read_exact(&mut buf)?;
 310                                 Ok($meth_read(&buf))
 311                         }
 312                 }
 313                 impl Readable for HighZeroBytesDroppedVarInt<$val_type> {
 314                         #[inline]
 315                         fn read<R: Read>(reader: &mut R) -> Result<HighZeroBytesDroppedVarInt<$val_type>, DecodeError> {
 316                                 // We need to accept short reads (read_len == 0) as "EOF" and handle them as simply
 317                                 // the high bytes being dropped. To do so, we start reading into the middle of buf
 318                                 // and then convert the appropriate number of bytes with extra high bytes out of
 319                                 // buf.
 320                                 let mut buf = [0; $len*2];
 321                                 let mut read_len = reader.read(&mut buf[$len..])?;
 322                                 let mut total_read_len = read_len;
 323                                 while read_len != 0 && total_read_len != $len {
 324                                         read_len = reader.read(&mut buf[($len + total_read_len)..])?;
 325                                         total_read_len += read_len;
 326                                 }
 327                                 if total_read_len == 0 || buf[$len] != 0 {
 328                                         let first_byte = $len - ($len - total_read_len);
 329                                         Ok(HighZeroBytesDroppedVarInt($meth_read(&buf[first_byte..first_byte + $len])))
 330                                 } else {
 331                                         // If the encoding had extra zero bytes, return a failure even though we know
 332                                         // what they meant (as the TLV test vectors require this)
 333                                         Err(DecodeError::InvalidValue)
 334                                 }
 335                         }
 336                 }
 337         }
 338 }
 339
 340 impl_writeable_primitive!(u64, be64_to_array, 8, slice_to_be64);
 341 impl_writeable_primitive!(u32, be32_to_array, 4, slice_to_be32);
 342 impl_writeable_primitive!(u16, be16_to_array, 2, slice_to_be16);
 343
 344 impl Writeable for u8 {
 345         #[inline]
 346         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 347                 writer.write_all(&[*self])
 348         }
 349 }
 350 impl Readable for u8 {
 351         #[inline]
 352         fn read<R: Read>(reader: &mut R) -> Result<u8, DecodeError> {
 353                 let mut buf = [0; 1];
 354                 reader.read_exact(&mut buf)?;
 355                 Ok(buf[0])
 356         }
 357 }
 358
 359 impl Writeable for bool {
 360         #[inline]
 361         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 362                 writer.write_all(&[if *self {1} else {0}])
 363         }
 364 }
 365 impl Readable for bool {
 366         #[inline]
 367         fn read<R: Read>(reader: &mut R) -> Result<bool, DecodeError> {
 368                 let mut buf = [0; 1];
 369                 reader.read_exact(&mut buf)?;
 370                 if buf[0] != 0 && buf[0] != 1 {
 371                         return Err(DecodeError::InvalidValue);
 372                 }
 373                 Ok(buf[0] == 1)
 374         }
 375 }
 376
 377 // u8 arrays
 378 macro_rules! impl_array {
 379         ( $size:expr ) => (
 380                 impl Writeable for [u8; $size]
 381                 {
 382                         #[inline]
 383                         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 384                                 w.write_all(self)
 385                         }
 386                 }
 387
 388                 impl Readable for [u8; $size]
 389                 {
 390                         #[inline]
 391                         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 392                                 let mut buf = [0u8; $size];
 393                                 r.read_exact(&mut buf)?;
 394                                 Ok(buf)
 395                         }
 396                 }
 397         );
 398 }
 399
 400 //TODO: performance issue with [u8; size] with impl_array!()
 401 impl_array!(3); // for rgb
 402 impl_array!(4); // for IPv4
 403 impl_array!(10); // for OnionV2
 404 impl_array!(16); // for IPv6
 405 impl_array!(32); // for channel id & hmac
 406 impl_array!(33); // for PublicKey
 407 impl_array!(64); // for Signature
 408 impl_array!(1300); // for OnionPacket.hop_data
 409
 410 // HashMap
 411 impl<K, V> Writeable for HashMap<K, V>
 412         where K: Writeable + Eq + Hash,
 413               V: Writeable
 414 {
 415         #[inline]
 416         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 417         (self.len() as u16).write(w)?;
 418                 for (key, value) in self.iter() {
 419                         key.write(w)?;
 420                         value.write(w)?;
 421                 }
 422                 Ok(())
 423         }
 424 }
 425
 426 impl<K, V> Readable for HashMap<K, V>
 427         where K: Readable + Eq + Hash,
 428               V: Readable
 429 {
 430         #[inline]
 431         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 432                 let len: u16 = Readable::read(r)?;
 433                 let mut ret = HashMap::with_capacity(len as usize);
 434                 for _ in 0..len {
 435                         ret.insert(K::read(r)?, V::read(r)?);
 436                 }
 437                 Ok(ret)
 438         }
 439 }
 440
 441 // Vectors
 442 impl Writeable for Vec<u8> {
 443         #[inline]
 444         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 445                 (self.len() as u16).write(w)?;
 446                 w.write_all(&self)
 447         }
 448 }
 449
 450 impl Readable for Vec<u8> {
 451         #[inline]
 452         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 453                 let len: u16 = Readable::read(r)?;
 454                 let mut ret = Vec::with_capacity(len as usize);
 455                 ret.resize(len as usize, 0);
 456                 r.read_exact(&mut ret)?;
 457                 Ok(ret)
 458         }
 459 }
 460 impl Writeable for Vec<Signature> {
 461         #[inline]
 462         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 463                 (self.len() as u16).write(w)?;
 464                 for e in self.iter() {
 465                         e.write(w)?;
 466                 }
 467                 Ok(())
 468         }
 469 }
 470
 471 impl Readable for Vec<Signature> {
 472         #[inline]
 473         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 474                 let len: u16 = Readable::read(r)?;
 475                 let byte_size = (len as usize)
 476                                 .checked_mul(33)
 477                                 .ok_or(DecodeError::BadLengthDescriptor)?;
 478                 if byte_size > MAX_BUF_SIZE {
 479                         return Err(DecodeError::BadLengthDescriptor);
 480                 }
 481                 let mut ret = Vec::with_capacity(len as usize);
 482                 for _ in 0..len { ret.push(Signature::read(r)?); }
 483                 Ok(ret)
 484         }
 485 }
 486
 487 impl Writeable for Script {
 488         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 489                 (self.len() as u16).write(w)?;
 490                 w.write_all(self.as_bytes())
 491         }
 492 }
 493
 494 impl Readable for Script {
 495         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 496                 let len = <u16 as Readable>::read(r)? as usize;
 497                 let mut buf = vec![0; len];
 498                 r.read_exact(&mut buf)?;
 499                 Ok(Script::from(buf))
 500         }
 501 }
 502
 503 impl Writeable for PublicKey {
 504         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 505                 self.serialize().write(w)
 506         }
 507 }
 508
 509 impl Readable for PublicKey {
 510         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 511                 let buf: [u8; 33] = Readable::read(r)?;
 512                 match PublicKey::from_slice(&buf) {
 513                         Ok(key) => Ok(key),
 514                         Err(_) => return Err(DecodeError::InvalidValue),
 515                 }
 516         }
 517 }
 518
 519 impl Writeable for SecretKey {
 520         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 521                 let mut ser = [0; 32];
 522                 ser.copy_from_slice(&self[..]);
 523                 ser.write(w)
 524         }
 525 }
 526
 527 impl Readable for SecretKey {
 528         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 529                 let buf: [u8; 32] = Readable::read(r)?;
 530                 match SecretKey::from_slice(&buf) {
 531                         Ok(key) => Ok(key),
 532                         Err(_) => return Err(DecodeError::InvalidValue),
 533                 }
 534         }
 535 }
 536
 537 impl Writeable for Sha256dHash {
 538         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 539                 w.write_all(&self[..])
 540         }
 541 }
 542
 543 impl Readable for Sha256dHash {
 544         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 545                 use bitcoin::hashes::Hash;
 546
 547                 let buf: [u8; 32] = Readable::read(r)?;
 548                 Ok(Sha256dHash::from_slice(&buf[..]).unwrap())
 549         }
 550 }
 551
 552 impl Writeable for Signature {
 553         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 554                 self.serialize_compact().write(w)
 555         }
 556 }
 557
 558 impl Readable for Signature {
 559         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 560                 let buf: [u8; 64] = Readable::read(r)?;
 561                 match Signature::from_compact(&buf) {
 562                         Ok(sig) => Ok(sig),
 563                         Err(_) => return Err(DecodeError::InvalidValue),
 564                 }
 565         }
 566 }
 567
 568 impl Writeable for PaymentPreimage {
 569         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 570                 self.0.write(w)
 571         }
 572 }
 573
 574 impl Readable for PaymentPreimage {
 575         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 576                 let buf: [u8; 32] = Readable::read(r)?;
 577                 Ok(PaymentPreimage(buf))
 578         }
 579 }
 580
 581 impl Writeable for PaymentHash {
 582         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 583                 self.0.write(w)
 584         }
 585 }
 586
 587 impl Readable for PaymentHash {
 588         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 589                 let buf: [u8; 32] = Readable::read(r)?;
 590                 Ok(PaymentHash(buf))
 591         }
 592 }
 593
 594 impl Writeable for PaymentSecret {
 595         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 596                 self.0.write(w)
 597         }
 598 }
 599
 600 impl Readable for PaymentSecret {
 601         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 602                 let buf: [u8; 32] = Readable::read(r)?;
 603                 Ok(PaymentSecret(buf))
 604         }
 605 }
 606
 607 impl<T: Writeable> Writeable for Option<T> {
 608         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 609                 match *self {
 610                         None => 0u8.write(w)?,
 611                         Some(ref data) => {
 612                                 let mut len_calc = LengthCalculatingWriter(0);
 613                                 data.write(&mut len_calc).expect("No in-memory data may fail to serialize");
 614                                 BigSize(len_calc.0 as u64 + 1).write(w)?;
 615                                 data.write(w)?;
 616                         }
 617                 }
 618                 Ok(())
 619         }
 620 }
 621
 622 impl<T: Readable> Readable for Option<T>
 623 {
 624         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 625                 match BigSize::read(r)?.0 {
 626                         0 => Ok(None),
 627                         len => {
 628                                 let mut reader = FixedLengthReader::new(r, len - 1);
 629                                 Ok(Some(Readable::read(&mut reader)?))
 630                         }
 631                 }
 632         }
 633 }
 634
 635 impl Writeable for OutPoint {
 636         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 637                 self.txid.write(w)?;
 638                 self.vout.write(w)?;
 639                 Ok(())
 640         }
 641 }
 642
 643 impl Readable for OutPoint {
 644         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 645                 let txid = Readable::read(r)?;
 646                 let vout = Readable::read(r)?;
 647                 Ok(OutPoint {
 648                         txid,
 649                         vout,
 650                 })
 651         }
 652 }
 653
 654 macro_rules! impl_consensus_ser {
 655         ($bitcoin_type: ty) => {
 656                 impl Writeable for $bitcoin_type {
 657                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 658                                 match self.consensus_encode(WriterWriteAdaptor(writer)) {
 659                                         Ok(_) => Ok(()),
 660                                         Err(consensus::encode::Error::Io(e)) => Err(e),
 661                                         Err(_) => panic!("We shouldn't get a consensus::encode::Error unless our Write generated an std::io::Error"),
 662                                 }
 663                         }
 664                 }
 665
 666                 impl Readable for $bitcoin_type {
 667                         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 668                                 match consensus::encode::Decodable::consensus_decode(r) {
 669                                         Ok(t) => Ok(t),
 670                                         Err(consensus::encode::Error::Io(ref e)) if e.kind() == ::std::io::ErrorKind::UnexpectedEof => Err(DecodeError::ShortRead),
 671                                         Err(consensus::encode::Error::Io(e)) => Err(DecodeError::Io(e)),
 672                                         Err(_) => Err(DecodeError::InvalidValue),
 673                                 }
 674                         }
 675                 }
 676         }
 677 }
 678 impl_consensus_ser!(Transaction);
 679 impl_consensus_ser!(TxOut);
 680
 681 impl<T: Readable> Readable for Mutex<T> {
 682         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 683                 let t: T = Readable::read(r)?;
 684                 Ok(Mutex::new(t))
 685         }
 686 }
 687 impl<T: Writeable> Writeable for Mutex<T> {
 688         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 689                 self.lock().unwrap().write(w)
 690         }
 691 }
 692
 693 impl<A: Readable, B: Readable> Readable for (A, B) {
 694         fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
 695                 let a: A = Readable::read(r)?;
 696                 let b: B = Readable::read(r)?;
 697                 Ok((a, b))
 698         }
 699 }
 700 impl<A: Writeable, B: Writeable> Writeable for (A, B) {
 701         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 702                 self.0.write(w)?;
 703                 self.1.write(w)
 704         }
 705 }