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

   1 use std::result::Result;
   2 use std::io::Read;
   3 use std::collections::HashMap;
   4 use std::hash::Hash;
   5
   6 use secp256k1::{Secp256k1, Signature};
   7 use secp256k1::key::PublicKey;
   8 use bitcoin::util::hash::Sha256dHash;
   9 use bitcoin::blockdata::script::Script;
  10 use std::marker::Sized;
  11 use ln::msgs::DecodeError;
  12
  13 use util::byte_utils::{be64_to_array, be32_to_array, be16_to_array, slice_to_be16, slice_to_be32, slice_to_be64};
  14
  15 const MAX_BUF_SIZE: usize = 64 * 1024;
  16
  17 /// A trait that is similar to std::io::Write but has one extra function which can be used to size
  18 /// buffers being written into.
  19 /// An impl is provided for any type that also impls std::io::Write which simply ignores size
  20 /// hints.
  21 pub trait Writer {
  22         /// Writes the given buf out. See std::io::Write::write_all for more
  23         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error>;
  24         /// Hints that data of the given size is about the be written. This may not always be called
  25         /// prior to data being written and may be safely ignored.
  26         fn size_hint(&mut self, size: usize);
  27 }
  28
  29 impl<W: ::std::io::Write> Writer for W {
  30         #[inline]
  31         fn write_all(&mut self, buf: &[u8]) -> Result<(), ::std::io::Error> {
  32                 <Self as ::std::io::Write>::write_all(self, buf)
  33         }
  34         #[inline]
  35         fn size_hint(&mut self, _size: usize) { }
  36 }
  37
  38 /// A trait that various rust-lightning types implement allowing them to be written out to a Writer
  39 pub trait Writeable<W: Writer> {
  40         /// Writes self out to the given Writer
  41         fn write(&self, writer: &mut W) -> Result<(), DecodeError>;
  42 }
  43
  44 /// A trait that various rust-lightning types implement allowing them to be read in from a Read
  45 pub trait Readable<R>
  46         where Self: Sized,
  47               R: Read
  48 {
  49         /// Reads a Self in from the given Read
  50         fn read(reader: &mut R) -> Result<Self, DecodeError>;
  51 }
  52
  53 macro_rules! impl_writeable_primitive {
  54         ($val_type:ty, $meth_write:ident, $len: expr, $meth_read:ident) => {
  55                 impl<W: Writer> Writeable<W> for $val_type {
  56                         #[inline]
  57                         fn write(&self, writer: &mut W) -> Result<(), DecodeError> {
  58                                 Ok(writer.write_all(&$meth_write(*self))?)
  59                         }
  60                 }
  61                 impl<R: Read> Readable<R> for $val_type {
  62                         #[inline]
  63                         fn read(reader: &mut R) -> Result<$val_type, DecodeError> {
  64                                 let mut buf = [0; $len];
  65                                 reader.read_exact(&mut buf)?;
  66                                 Ok($meth_read(&buf))
  67                         }
  68                 }
  69         }
  70 }
  71
  72 impl_writeable_primitive!(u64, be64_to_array, 8, slice_to_be64);
  73 impl_writeable_primitive!(u32, be32_to_array, 4, slice_to_be32);
  74 impl_writeable_primitive!(u16, be16_to_array, 2, slice_to_be16);
  75
  76 impl<W: Writer> Writeable<W> for u8 {
  77         #[inline]
  78         fn write(&self, writer: &mut W) -> Result<(), DecodeError> {
  79                 Ok(writer.write_all(&[*self])?)
  80         }
  81 }
  82 impl<R: Read> Readable<R> for u8 {
  83         #[inline]
  84         fn read(reader: &mut R) -> Result<u8, DecodeError> {
  85                 let mut buf = [0; 1];
  86                 reader.read_exact(&mut buf)?;
  87                 Ok(buf[0])
  88         }
  89 }
  90
  91 impl<W: Writer> Writeable<W> for bool {
  92         #[inline]
  93         fn write(&self, writer: &mut W) -> Result<(), DecodeError> {
  94                 Ok(writer.write_all(&[if *self {1} else {0}])?)
  95         }
  96 }
  97 impl<R: Read> Readable<R> for bool {
  98         #[inline]
  99         fn read(reader: &mut R) -> Result<bool, DecodeError> {
 100                 let mut buf = [0; 1];
 101                 reader.read_exact(&mut buf)?;
 102                 if buf[0] != 0 && buf[0] != 1 {
 103                         return Err(DecodeError::InvalidValue);
 104                 }
 105                 Ok(buf[0] == 1)
 106         }
 107 }
 108
 109 // u8 arrays
 110 macro_rules! impl_array {
 111         ( $size:expr ) => (
 112                 impl<W: Writer> Writeable<W> for [u8; $size]
 113                 {
 114                         #[inline]
 115                         fn write(&self, w: &mut W) -> Result<(), DecodeError> {
 116                                 w.write_all(self)?;
 117                                 Ok(())
 118                         }
 119                 }
 120
 121                 impl<R: Read> Readable<R> for [u8; $size]
 122                 {
 123                         #[inline]
 124                         fn read(r: &mut R) -> Result<Self, DecodeError> {
 125                                 let mut buf = [0u8; $size];
 126                                 r.read_exact(&mut buf)?;
 127                                 Ok(buf)
 128                         }
 129                 }
 130         );
 131 }
 132
 133 //TODO: performance issue with [u8; size] with impl_array!()
 134 impl_array!(32); // for channel id & hmac
 135 impl_array!(33); // for PublicKey
 136 impl_array!(64); // for Signature
 137 impl_array!(1300); // for OnionPacket.hop_data
 138
 139 // HashMap
 140 impl<W, K, V> Writeable<W> for HashMap<K, V>
 141         where W: Writer,
 142               K: Writeable<W> + Eq + Hash,
 143               V: Writeable<W>
 144 {
 145         #[inline]
 146         fn write(&self, w: &mut W) -> Result<(), DecodeError> {
 147         (self.len() as u16).write(w)?;
 148                 for (key, value) in self.iter() {
 149                         key.write(w)?;
 150                         value.write(w)?;
 151                 }
 152                 Ok(())
 153         }
 154 }
 155
 156 impl<R, K, V> Readable<R> for HashMap<K, V>
 157         where R: Read,
 158               K: Readable<R> + Eq + Hash,
 159               V: Readable<R>
 160 {
 161         #[inline]
 162         fn read(r: &mut R) -> Result<Self, DecodeError> {
 163                 let len: u16 = Readable::read(r)?;
 164                 let mut ret = HashMap::with_capacity(len as usize);
 165                 for _ in 0..len {
 166                         ret.insert(K::read(r)?, V::read(r)?);
 167                 }
 168                 Ok(ret)
 169         }
 170 }
 171
 172 // Vectors
 173 impl<W: Writer> Writeable<W> for Vec<u8> {
 174         #[inline]
 175         fn write(&self, w: &mut W) -> Result<(), DecodeError> {
 176                 (self.len() as u16).write(w)?;
 177                 Ok(w.write_all(&self)?)
 178         }
 179 }
 180
 181 impl<R: Read> Readable<R> for Vec<u8> {
 182         #[inline]
 183         fn read(r: &mut R) -> Result<Self, DecodeError> {
 184                 let len: u16 = Readable::read(r)?;
 185                 let mut ret = Vec::with_capacity(len as usize);
 186                 ret.resize(len as usize, 0);
 187                 r.read_exact(&mut ret)?;
 188                 Ok(ret)
 189         }
 190 }
 191 impl<W: Writer> Writeable<W> for Vec<Signature> {
 192         #[inline]
 193         fn write(&self, w: &mut W) -> Result<(), DecodeError> {
 194                 let byte_size = (self.len() as usize)
 195                                 .checked_mul(33)
 196                                 .ok_or(DecodeError::BadLengthDescriptor)?;
 197                 if byte_size > MAX_BUF_SIZE {
 198                         return Err(DecodeError::BadLengthDescriptor);
 199                 }
 200                 (self.len() as u16).write(w)?;
 201                 for e in self.iter() {
 202                         e.write(w)?;
 203                 }
 204                 Ok(())
 205         }
 206 }
 207
 208 impl<R: Read> Readable<R> for Vec<Signature> {
 209         #[inline]
 210         fn read(r: &mut R) -> Result<Self, DecodeError> {
 211                 let len: u16 = Readable::read(r)?;
 212                 let byte_size = (len as usize)
 213                                 .checked_mul(33)
 214                                 .ok_or(DecodeError::BadLengthDescriptor)?;
 215                 if byte_size > MAX_BUF_SIZE {
 216                         return Err(DecodeError::BadLengthDescriptor);
 217                 }
 218                 let mut ret = Vec::with_capacity(len as usize);
 219                 for _ in 0..len { ret.push(Signature::read(r)?); }
 220                 Ok(ret)
 221         }
 222 }
 223
 224 impl<W: Writer> Writeable<W> for Script {
 225         fn write(&self, w: &mut W) -> Result<(), DecodeError> {
 226                 (self.len() as u16).write(w)?;
 227                 Ok(w.write_all(self.as_bytes())?)
 228         }
 229 }
 230
 231 impl<R: Read> Readable<R> for Script {
 232         fn read(r: &mut R) -> Result<Self, DecodeError> {
 233                 let len = <u16 as Readable<R>>::read(r)? as usize;
 234                 let mut buf = vec![0; len];
 235                 r.read_exact(&mut buf)?;
 236                 Ok(Script::from(buf))
 237         }
 238 }
 239
 240 impl<W: Writer> Writeable<W> for Option<Script> {
 241         fn write(&self, w: &mut W) -> Result<(), DecodeError> {
 242                 if let &Some(ref script) = self {
 243                         script.write(w)?;
 244                 }
 245                 Ok(())
 246         }
 247 }
 248
 249 impl<R: Read> Readable<R> for Option<Script> {
 250         fn read(r: &mut R) -> Result<Self, DecodeError> {
 251                 match <u16 as Readable<R>>::read(r) {
 252                         Ok(len) => {
 253                                 let mut buf = vec![0; len as usize];
 254                                 r.read_exact(&mut buf)?;
 255                                 Ok(Some(Script::from(buf)))
 256                         },
 257                         Err(DecodeError::ShortRead) => Ok(None),
 258                         Err(e) => Err(e)
 259                 }
 260         }
 261 }
 262
 263 impl<W: Writer> Writeable<W> for PublicKey {
 264         fn write(&self, w: &mut W) -> Result<(), DecodeError> {
 265                 self.serialize().write(w)
 266         }
 267 }
 268
 269 impl<R: Read> Readable<R> for PublicKey {
 270         fn read(r: &mut R) -> Result<Self, DecodeError> {
 271                 let buf: [u8; 33] = Readable::read(r)?;
 272                 match PublicKey::from_slice(&Secp256k1::without_caps(), &buf) {
 273                         Ok(key) => Ok(key),
 274                         Err(_) => return Err(DecodeError::BadPublicKey),
 275                 }
 276         }
 277 }
 278
 279 impl<W: Writer> Writeable<W> for Sha256dHash {
 280         fn write(&self, w: &mut W) -> Result<(), DecodeError> {
 281                 self.as_bytes().write(w)
 282         }
 283 }
 284
 285 impl<R: Read> Readable<R> for Sha256dHash {
 286         fn read(r: &mut R) -> Result<Self, DecodeError> {
 287                 let buf: [u8; 32] = Readable::read(r)?;
 288                 Ok(From::from(&buf[..]))
 289         }
 290 }
 291
 292 impl<W: Writer> Writeable<W> for Signature {
 293         fn write(&self, w: &mut W) -> Result<(), DecodeError> {
 294                 self.serialize_compact(&Secp256k1::without_caps()).write(w)
 295         }
 296 }
 297
 298 impl<R: Read> Readable<R> for Signature {
 299         fn read(r: &mut R) -> Result<Self, DecodeError> {
 300                 let buf: [u8; 64] = Readable::read(r)?;
 301                 match Signature::from_compact(&Secp256k1::without_caps(), &buf) {
 302                         Ok(sig) => Ok(sig),
 303                         Err(_) => return Err(DecodeError::BadSignature),
 304                 }
 305         }
 306 }