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

   1 use std::result::Result;
   2 use std::io::{Read, Write};
   3 use std::collections::HashMap;
   4 use std::hash::Hash;
   5 use std::mem;
   6
   7 use secp256k1::{Secp256k1, Signature};
   8 use secp256k1::key::PublicKey;
   9 use bitcoin::util::hash::Sha256dHash;
  10 use bitcoin::blockdata::script::Script;
  11 use std::marker::Sized;
  12 use ln::msgs::DecodeError;
  13
  14 use util::byte_utils::{be64_to_array, be32_to_array, be16_to_array, slice_to_be16, slice_to_be32, slice_to_be64};
  15
  16 const MAX_BUF_SIZE: usize = 64 * 1024;
  17
  18 /// A struct that holds an std::io::Write-impl'ing object and implements various
  19 /// rust-lightning-specific write functions.
  20 pub struct Writer<W: Write> { writer: W }
  21 /// A struct that holds an std::io::Read-impl'ing object and implements various
  22 /// rust-lightning-specific read functions.
  23 pub struct Reader<R: Read> { reader: R }
  24
  25 /// A trait that various rust-lightning types implement allowing them to be written out to a Writer
  26 pub trait Writeable<W: Write> {
  27         /// Writes self out to the given Writer
  28         fn write(&self, writer: &mut Writer<W>) -> Result<(), DecodeError>;
  29 }
  30
  31 /// A trait that various rust-lightning types implement allowing them to be read in from a Reader
  32 pub trait Readable<R>
  33         where Self: Sized,
  34               R: Read
  35 {
  36         /// Reads a Self in from the given Reader
  37         fn read(reader: &mut Reader<R>) -> Result<Self, DecodeError>;
  38 }
  39
  40 impl<W: Write> Writer<W> {
  41         /// Creates a new Writer from an std::io::Write-impl'ing object
  42         pub fn new(writer: W) -> Writer<W> {
  43                 return Writer { writer }
  44         }
  45         /// Consumes this object and returns the original writer
  46         pub fn into_inner(self) -> W { self.writer }
  47         /// Gets a reference to the original writer
  48         pub fn get_ref(&self) -> &W { &self.writer }
  49         fn write_u64(&mut self, v: u64) -> Result<(), DecodeError> {
  50                 Ok(self.writer.write_all(&be64_to_array(v))?)
  51         }
  52         fn write_u32(&mut self, v: u32) -> Result<(), DecodeError> {
  53                 Ok(self.writer.write_all(&be32_to_array(v))?)
  54         }
  55         fn write_u16(&mut self, v: u16) -> Result<(), DecodeError> {
  56                 Ok(self.writer.write_all(&be16_to_array(v))?)
  57         }
  58         fn write_u8(&mut self, v: u8) -> Result<(), DecodeError> {
  59                 Ok(self.writer.write_all(&[v])?)
  60         }
  61         fn write_bool(&mut self, v: bool) -> Result<(), DecodeError> {
  62                 Ok(self.writer.write_all(&[if v {1} else {0}])?)
  63         }
  64         pub(crate) fn write_all(&mut self, v: &[u8]) -> Result<(), DecodeError> {
  65                 Ok(self.writer.write_all(v)?)
  66         }
  67 }
  68
  69 impl<R: Read> Reader<R> {
  70         /// Creates a new Reader from an std::io::Read-impl'ing object
  71         pub fn new(reader: R) -> Reader<R> {
  72                 return Reader { reader }
  73         }
  74         /// Consumes this object and returns the original reader
  75         pub fn into_inner(self) -> R { self.reader }
  76         /// Gets a reference to the original reader
  77         pub fn get_ref(&self) -> &R { &self.reader }
  78
  79         fn read_u64(&mut self) -> Result<u64, DecodeError> {
  80                 let mut buf = [0; 8];
  81                 self.reader.read_exact(&mut buf)?;
  82                 Ok(slice_to_be64(&buf))
  83         }
  84
  85         fn read_u32(&mut self) -> Result<u32, DecodeError> {
  86                 let mut buf = [0; 4];
  87                 self.reader.read_exact(&mut buf)?;
  88                 Ok(slice_to_be32(&buf))
  89         }
  90
  91         fn read_u16(&mut self) -> Result<u16, DecodeError> {
  92                 let mut buf = [0; 2];
  93                 self.reader.read_exact(&mut buf)?;
  94                 Ok(slice_to_be16(&buf))
  95         }
  96
  97         fn read_u8(&mut self) -> Result<u8, DecodeError> {
  98                 let mut buf = [0; 1];
  99                 self.reader.read_exact(&mut buf)?;
 100                 Ok(buf[0])
 101         }
 102         fn read_bool(&mut self) -> Result<bool, DecodeError> {
 103                 let mut buf = [0; 1];
 104                 self.reader.read_exact(&mut buf)?;
 105                 if buf[0] != 0 && buf[0] != 1 {
 106                         return Err(DecodeError::InvalidValue);
 107                 }
 108                 Ok(buf[0] == 1)
 109         }
 110         pub(crate) fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), DecodeError> {
 111                 Ok(self.reader.read_exact(buf)?)
 112         }
 113         pub(crate) fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, DecodeError> {
 114                 Ok(self.reader.read_to_end(buf)?)
 115         }
 116 }
 117
 118 macro_rules! impl_writeable_primitive {
 119         ($val_type:ty, $meth_write:ident, $meth_read:ident) => {
 120                 impl<W:Write> Writeable<W> for $val_type {
 121                         #[inline]
 122                         fn write(&self, writer: &mut Writer<W>) -> Result<(), DecodeError> {
 123                                 writer.$meth_write(*self)
 124                         }
 125                 }
 126                 impl<R:Read> Readable<R> for $val_type {
 127                         #[inline]
 128                         fn read(reader: &mut Reader<R>) -> Result<$val_type, DecodeError> {
 129                                 reader.$meth_read()
 130                         }
 131                 }
 132         }
 133 }
 134
 135 impl_writeable_primitive!(u64, write_u64, read_u64);
 136 impl_writeable_primitive!(u32, write_u32, read_u32);
 137 impl_writeable_primitive!(u16, write_u16, read_u16);
 138 impl_writeable_primitive!(u8, write_u8, read_u8);
 139 impl_writeable_primitive!(bool, write_bool, read_bool);
 140
 141 // u8 arrays
 142 macro_rules! impl_array {
 143         ( $size:expr ) => (
 144                 impl<W> Writeable<W> for [u8; $size]
 145                         where W: Write
 146                 {
 147                         #[inline]
 148                         fn write(&self, w: &mut Writer<W>) -> Result<(), DecodeError> {
 149                                 w.write_all(self)?;
 150                                 Ok(())
 151                         }
 152                 }
 153
 154                 impl<R> Readable<R> for [u8; $size]
 155                         where R: Read
 156                 {
 157                         #[inline]
 158                         fn read(r: &mut Reader<R>) -> Result<Self, DecodeError> {
 159                                 let mut buf = [0u8; $size];
 160                                 r.read_exact(&mut buf)?;
 161                                 Ok(buf)
 162                         }
 163                 }
 164         );
 165 }
 166
 167 //TODO: performance issue with [u8; size] with impl_array!()
 168 impl_array!(32); // for channel id & hmac
 169 impl_array!(33); // for PublicKey
 170 impl_array!(64); // for Signature
 171 impl_array!(1300); // for OnionPacket.hop_data
 172
 173 // HashMap
 174 impl<W, K, V> Writeable<W> for HashMap<K, V>
 175         where W: Write,
 176               K: Writeable<W> + Eq + Hash,
 177               V: Writeable<W>
 178 {
 179         #[inline]
 180         fn write(&self, w: &mut Writer<W>) -> Result<(), DecodeError> {
 181         (self.len() as u16).write(w)?;
 182                 for (key, value) in self.iter() {
 183                         key.write(w)?;
 184                         value.write(w)?;
 185                 }
 186                 Ok(())
 187         }
 188 }
 189
 190 impl<R, K, V> Readable<R> for HashMap<K, V>
 191         where R: Read,
 192               K: Readable<R> + Eq + Hash,
 193               V: Readable<R>
 194 {
 195         #[inline]
 196         fn read(r: &mut Reader<R>) -> Result<Self, DecodeError> {
 197                 let len: u16 = Readable::read(r)?;
 198                 let mut ret = HashMap::with_capacity(len as usize);
 199                 for _ in 0..len {
 200                         ret.insert(K::read(r)?, V::read(r)?);
 201                 }
 202                 Ok(ret)
 203         }
 204 }
 205
 206 // Vectors
 207 impl<W: Write, T: Writeable<W>> Writeable<W> for Vec<T> {
 208         #[inline]
 209         fn write(&self, w: &mut Writer<W>) -> Result<(), DecodeError> {
 210                 let byte_size = (self.len() as usize)
 211                                 .checked_mul(mem::size_of::<T>())
 212                                 .ok_or(DecodeError::BadLengthDescriptor)?;
 213                 if byte_size > MAX_BUF_SIZE {
 214                         return Err(DecodeError::BadLengthDescriptor);
 215                 }
 216                 (self.len() as u16).write(w)?;
 217                 // performance with Vec<u8>
 218                 for e in self.iter() {
 219                         e.write(w)?;
 220                 }
 221                 Ok(())
 222         }
 223 }
 224
 225 impl<R: Read, T: Readable<R>> Readable<R> for Vec<T> {
 226         #[inline]
 227         fn read(r: &mut Reader<R>) -> Result<Self, DecodeError> {
 228                 let len: u16 = Readable::read(r)?;
 229                 let byte_size = (len as usize)
 230                                 .checked_mul(mem::size_of::<T>())
 231                                 .ok_or(DecodeError::BadLengthDescriptor)?;
 232                 if byte_size > MAX_BUF_SIZE {
 233                         return Err(DecodeError::BadLengthDescriptor);
 234                 }
 235                 let mut ret = Vec::with_capacity(len as usize);
 236                 for _ in 0..len { ret.push(T::read(r)?); }
 237                 Ok(ret)
 238         }
 239 }
 240
 241 impl<W: Write> Writeable<W> for Script {
 242         fn write(&self, w: &mut Writer<W>) -> Result<(), DecodeError> {
 243                 self.to_bytes().to_vec().write(w)
 244         }
 245 }
 246
 247 impl<R: Read> Readable<R> for Script {
 248         fn read(r: &mut Reader<R>) -> Result<Self, DecodeError> {
 249                 let len = <u16 as Readable<R>>::read(r)? as usize;
 250                 let mut buf = vec![0; len];
 251                 r.read_exact(&mut buf)?;
 252                 Ok(Script::from(buf))
 253         }
 254 }
 255
 256 impl<W: Write> Writeable<W> for Option<Script> {
 257         fn write(&self, w: &mut Writer<W>) -> Result<(), DecodeError> {
 258                 if let &Some(ref script) = self {
 259                         script.write(w)?;
 260                 }
 261                 Ok(())
 262         }
 263 }
 264
 265 impl<R: Read> Readable<R> for Option<Script> {
 266         fn read(r: &mut Reader<R>) -> Result<Self, DecodeError> {
 267                 match <u16 as Readable<R>>::read(r) {
 268                         Ok(len) => {
 269                                 let mut buf = vec![0; len as usize];
 270                                 r.read_exact(&mut buf)?;
 271                                 Ok(Some(Script::from(buf)))
 272                         },
 273                         Err(DecodeError::ShortRead) => Ok(None),
 274                         Err(e) => Err(e)
 275                 }
 276         }
 277 }
 278
 279 impl<W: Write> Writeable<W> for PublicKey {
 280         fn write(&self, w: &mut Writer<W>) -> Result<(), DecodeError> {
 281                 self.serialize().write(w)
 282         }
 283 }
 284
 285 impl<R: Read> Readable<R> for PublicKey {
 286         fn read(r: &mut Reader<R>) -> Result<Self, DecodeError> {
 287                 let buf: [u8; 33] = Readable::read(r)?;
 288                 match PublicKey::from_slice(&Secp256k1::without_caps(), &buf) {
 289                         Ok(key) => Ok(key),
 290                         Err(_) => return Err(DecodeError::BadPublicKey),
 291                 }
 292         }
 293 }
 294
 295 impl<W: Write> Writeable<W> for Sha256dHash {
 296         fn write(&self, w: &mut Writer<W>) -> Result<(), DecodeError> {
 297                 self.as_bytes().write(w)
 298         }
 299 }
 300
 301 impl<R: Read> Readable<R> for Sha256dHash {
 302         fn read(r: &mut Reader<R>) -> Result<Self, DecodeError> {
 303                 let buf: [u8; 32] = Readable::read(r)?;
 304                 Ok(From::from(&buf[..]))
 305         }
 306 }
 307
 308 impl<W: Write> Writeable<W> for Signature {
 309         fn write(&self, w: &mut Writer<W>) -> Result<(), DecodeError> {
 310                 self.serialize_compact(&Secp256k1::without_caps()).write(w)
 311         }
 312 }
 313
 314 impl<R: Read> Readable<R> for Signature {
 315         fn read(r: &mut Reader<R>) -> Result<Self, DecodeError> {
 316                 let buf: [u8; 64] = Readable::read(r)?;
 317                 match Signature::from_compact(&Secp256k1::without_caps(), &buf) {
 318                         Ok(sig) => Ok(sig),
 319                         Err(_) => return Err(DecodeError::BadSignature),
 320                 }
 321         }
 322 }