_ 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<(), ::std::io::Error>;
  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 $val_type {
  56                         #[inline]
  57                         fn write(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
  58                                 writer.write_all(&$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<(), ::std::io::Error> {
  79                 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<(), ::std::io::Error> {
  94                 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<(), ::std::io::Error> {
 116                                 w.write_all(self)
 117                         }
 118                 }
 119
 120                 impl<R: Read> Readable<R> for [u8; $size]
 121                 {
 122                         #[inline]
 123                         fn read(r: &mut R) -> Result<Self, DecodeError> {
 124                                 let mut buf = [0u8; $size];
 125                                 r.read_exact(&mut buf)?;
 126                                 Ok(buf)
 127                         }
 128                 }
 129         );
 130 }
 131
 132 //TODO: performance issue with [u8; size] with impl_array!()
 133 impl_array!(32); // for channel id & hmac
 134 impl_array!(33); // for PublicKey
 135 impl_array!(64); // for Signature
 136 impl_array!(1300); // for OnionPacket.hop_data
 137
 138 // HashMap
 139 impl<W, K, V> Writeable<W> for HashMap<K, V>
 140         where W: Writer,
 141               K: Writeable<W> + Eq + Hash,
 142               V: Writeable<W>
 143 {
 144         #[inline]
 145         fn write(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 146         (self.len() as u16).write(w)?;
 147                 for (key, value) in self.iter() {
 148                         key.write(w)?;
 149                         value.write(w)?;
 150                 }
 151                 Ok(())
 152         }
 153 }
 154
 155 impl<R, K, V> Readable<R> for HashMap<K, V>
 156         where R: Read,
 157               K: Readable<R> + Eq + Hash,
 158               V: Readable<R>
 159 {
 160         #[inline]
 161         fn read(r: &mut R) -> Result<Self, DecodeError> {
 162                 let len: u16 = Readable::read(r)?;
 163                 let mut ret = HashMap::with_capacity(len as usize);
 164                 for _ in 0..len {
 165                         ret.insert(K::read(r)?, V::read(r)?);
 166                 }
 167                 Ok(ret)
 168         }
 169 }
 170
 171 // Vectors
 172 impl<W: Writer> Writeable<W> for Vec<u8> {
 173         #[inline]
 174         fn write(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 175                 (self.len() as u16).write(w)?;
 176                 w.write_all(&self)
 177         }
 178 }
 179
 180 impl<R: Read> Readable<R> for Vec<u8> {
 181         #[inline]
 182         fn read(r: &mut R) -> Result<Self, DecodeError> {
 183                 let len: u16 = Readable::read(r)?;
 184                 let mut ret = Vec::with_capacity(len as usize);
 185                 ret.resize(len as usize, 0);
 186                 r.read_exact(&mut ret)?;
 187                 Ok(ret)
 188         }
 189 }
 190 impl<W: Writer> Writeable<W> for Vec<Signature> {
 191         #[inline]
 192         fn write(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 193                 (self.len() as u16).write(w)?;
 194                 for e in self.iter() {
 195                         e.write(w)?;
 196                 }
 197                 Ok(())
 198         }
 199 }
 200
 201 impl<R: Read> Readable<R> for Vec<Signature> {
 202         #[inline]
 203         fn read(r: &mut R) -> Result<Self, DecodeError> {
 204                 let len: u16 = Readable::read(r)?;
 205                 let byte_size = (len as usize)
 206                                 .checked_mul(33)
 207                                 .ok_or(DecodeError::BadLengthDescriptor)?;
 208                 if byte_size > MAX_BUF_SIZE {
 209                         return Err(DecodeError::BadLengthDescriptor);
 210                 }
 211                 let mut ret = Vec::with_capacity(len as usize);
 212                 for _ in 0..len { ret.push(Signature::read(r)?); }
 213                 Ok(ret)
 214         }
 215 }
 216
 217 impl<W: Writer> Writeable<W> for Script {
 218         fn write(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 219                 (self.len() as u16).write(w)?;
 220                 w.write_all(self.as_bytes())
 221         }
 222 }
 223
 224 impl<R: Read> Readable<R> for Script {
 225         fn read(r: &mut R) -> Result<Self, DecodeError> {
 226                 let len = <u16 as Readable<R>>::read(r)? as usize;
 227                 let mut buf = vec![0; len];
 228                 r.read_exact(&mut buf)?;
 229                 Ok(Script::from(buf))
 230         }
 231 }
 232
 233 impl<W: Writer> Writeable<W> for Option<Script> {
 234         fn write(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 235                 if let &Some(ref script) = self {
 236                         script.write(w)?;
 237                 }
 238                 Ok(())
 239         }
 240 }
 241
 242 impl<R: Read> Readable<R> for Option<Script> {
 243         fn read(r: &mut R) -> Result<Self, DecodeError> {
 244                 match <u16 as Readable<R>>::read(r) {
 245                         Ok(len) => {
 246                                 let mut buf = vec![0; len as usize];
 247                                 r.read_exact(&mut buf)?;
 248                                 Ok(Some(Script::from(buf)))
 249                         },
 250                         Err(DecodeError::ShortRead) => Ok(None),
 251                         Err(e) => Err(e)
 252                 }
 253         }
 254 }
 255
 256 impl<W: Writer> Writeable<W> for PublicKey {
 257         fn write(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 258                 self.serialize().write(w)
 259         }
 260 }
 261
 262 impl<R: Read> Readable<R> for PublicKey {
 263         fn read(r: &mut R) -> Result<Self, DecodeError> {
 264                 let buf: [u8; 33] = Readable::read(r)?;
 265                 match PublicKey::from_slice(&Secp256k1::without_caps(), &buf) {
 266                         Ok(key) => Ok(key),
 267                         Err(_) => return Err(DecodeError::BadPublicKey),
 268                 }
 269         }
 270 }
 271
 272 impl<W: Writer> Writeable<W> for Sha256dHash {
 273         fn write(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 274                 self.as_bytes().write(w)
 275         }
 276 }
 277
 278 impl<R: Read> Readable<R> for Sha256dHash {
 279         fn read(r: &mut R) -> Result<Self, DecodeError> {
 280                 let buf: [u8; 32] = Readable::read(r)?;
 281                 Ok(From::from(&buf[..]))
 282         }
 283 }
 284
 285 impl<W: Writer> Writeable<W> for Signature {
 286         fn write(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 287                 self.serialize_compact(&Secp256k1::without_caps()).write(w)
 288         }
 289 }
 290
 291 impl<R: Read> Readable<R> for Signature {
 292         fn read(r: &mut R) -> Result<Self, DecodeError> {
 293                 let buf: [u8; 64] = Readable::read(r)?;
 294                 match Signature::from_compact(&Secp256k1::without_caps(), &buf) {
 295                         Ok(sig) => Ok(sig),
 296                         Err(_) => return Err(DecodeError::BadSignature),
 297                 }
 298         }
 299 }