_ 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 {
  40         /// Writes self out to the given Writer
  41         fn write<W: Writer>(&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 Writeable for $val_type {
  56                         #[inline]
  57                         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
  58                                 writer.write_all(&$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 Writeable for u8 {
  77         #[inline]
  78         fn write<W: Writer>(&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 Writeable for bool {
  92         #[inline]
  93         fn write<W: Writer>(&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 Writeable for [u8; $size]
 113                 {
 114                         #[inline]
 115                         fn write<W: Writer>(&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<K, V> Writeable for HashMap<K, V>
 140         where K: Writeable + Eq + Hash,
 141               V: Writeable
 142 {
 143         #[inline]
 144         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 145         (self.len() as u16).write(w)?;
 146                 for (key, value) in self.iter() {
 147                         key.write(w)?;
 148                         value.write(w)?;
 149                 }
 150                 Ok(())
 151         }
 152 }
 153
 154 impl<R, K, V> Readable<R> for HashMap<K, V>
 155         where R: Read,
 156               K: Readable<R> + Eq + Hash,
 157               V: Readable<R>
 158 {
 159         #[inline]
 160         fn read(r: &mut R) -> Result<Self, DecodeError> {
 161                 let len: u16 = Readable::read(r)?;
 162                 let mut ret = HashMap::with_capacity(len as usize);
 163                 for _ in 0..len {
 164                         ret.insert(K::read(r)?, V::read(r)?);
 165                 }
 166                 Ok(ret)
 167         }
 168 }
 169
 170 // Vectors
 171 impl Writeable for Vec<u8> {
 172         #[inline]
 173         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 174                 (self.len() as u16).write(w)?;
 175                 w.write_all(&self)
 176         }
 177 }
 178
 179 impl<R: Read> Readable<R> for Vec<u8> {
 180         #[inline]
 181         fn read(r: &mut R) -> Result<Self, DecodeError> {
 182                 let len: u16 = Readable::read(r)?;
 183                 let mut ret = Vec::with_capacity(len as usize);
 184                 ret.resize(len as usize, 0);
 185                 r.read_exact(&mut ret)?;
 186                 Ok(ret)
 187         }
 188 }
 189 impl Writeable for Vec<Signature> {
 190         #[inline]
 191         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 192                 (self.len() as u16).write(w)?;
 193                 for e in self.iter() {
 194                         e.write(w)?;
 195                 }
 196                 Ok(())
 197         }
 198 }
 199
 200 impl<R: Read> Readable<R> for Vec<Signature> {
 201         #[inline]
 202         fn read(r: &mut R) -> Result<Self, DecodeError> {
 203                 let len: u16 = Readable::read(r)?;
 204                 let byte_size = (len as usize)
 205                                 .checked_mul(33)
 206                                 .ok_or(DecodeError::BadLengthDescriptor)?;
 207                 if byte_size > MAX_BUF_SIZE {
 208                         return Err(DecodeError::BadLengthDescriptor);
 209                 }
 210                 let mut ret = Vec::with_capacity(len as usize);
 211                 for _ in 0..len { ret.push(Signature::read(r)?); }
 212                 Ok(ret)
 213         }
 214 }
 215
 216 impl Writeable for Script {
 217         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 218                 (self.len() as u16).write(w)?;
 219                 w.write_all(self.as_bytes())
 220         }
 221 }
 222
 223 impl<R: Read> Readable<R> for Script {
 224         fn read(r: &mut R) -> Result<Self, DecodeError> {
 225                 let len = <u16 as Readable<R>>::read(r)? as usize;
 226                 let mut buf = vec![0; len];
 227                 r.read_exact(&mut buf)?;
 228                 Ok(Script::from(buf))
 229         }
 230 }
 231
 232 impl Writeable for Option<Script> {
 233         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 234                 if let &Some(ref script) = self {
 235                         script.write(w)?;
 236                 }
 237                 Ok(())
 238         }
 239 }
 240
 241 impl<R: Read> Readable<R> for Option<Script> {
 242         fn read(r: &mut R) -> Result<Self, DecodeError> {
 243                 match <u16 as Readable<R>>::read(r) {
 244                         Ok(len) => {
 245                                 let mut buf = vec![0; len as usize];
 246                                 r.read_exact(&mut buf)?;
 247                                 Ok(Some(Script::from(buf)))
 248                         },
 249                         Err(DecodeError::ShortRead) => Ok(None),
 250                         Err(e) => Err(e)
 251                 }
 252         }
 253 }
 254
 255 impl Writeable for PublicKey {
 256         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 257                 self.serialize().write(w)
 258         }
 259 }
 260
 261 impl<R: Read> Readable<R> for PublicKey {
 262         fn read(r: &mut R) -> Result<Self, DecodeError> {
 263                 let buf: [u8; 33] = Readable::read(r)?;
 264                 match PublicKey::from_slice(&Secp256k1::without_caps(), &buf) {
 265                         Ok(key) => Ok(key),
 266                         Err(_) => return Err(DecodeError::BadPublicKey),
 267                 }
 268         }
 269 }
 270
 271 impl Writeable for Sha256dHash {
 272         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 273                 self.as_bytes().write(w)
 274         }
 275 }
 276
 277 impl<R: Read> Readable<R> for Sha256dHash {
 278         fn read(r: &mut R) -> Result<Self, DecodeError> {
 279                 let buf: [u8; 32] = Readable::read(r)?;
 280                 Ok(From::from(&buf[..]))
 281         }
 282 }
 283
 284 impl Writeable for Signature {
 285         fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
 286                 self.serialize_compact(&Secp256k1::without_caps()).write(w)
 287         }
 288 }
 289
 290 impl<R: Read> Readable<R> for Signature {
 291         fn read(r: &mut R) -> Result<Self, DecodeError> {
 292                 let buf: [u8; 64] = Readable::read(r)?;
 293                 match Signature::from_compact(&Secp256k1::without_caps(), &buf) {
 294                         Ok(sig) => Ok(sig),
 295                         Err(_) => return Err(DecodeError::BadSignature),
 296                 }
 297         }
 298 }