rust-bitcoin-unsafe-fast/src/network/encodable.rs

519 lines
19 KiB
Rust

// Rust Bitcoin Library
// Written in 2014 by
// Andrew Poelstra <apoelstra@wpsoftware.net>
//
// To the extent possible under law, the author(s) have dedicated all
// copyright and related and neighboring rights to this software to
// the public domain worldwide. This software is distributed without
// any warranty.
//
// You should have received a copy of the CC0 Public Domain Dedication
// along with this software.
// If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
//
//! # Consensus-encodable types
//!
//! This is basically a replacement of the `Encodable` trait which does
//! normalization for endianness, etc., to ensure that the encoding
//! matches for endianness, etc., to ensure that the encoding matches
//! the network consensus encoding.
//!
//! Essentially, anything that must go on the -disk- or -network- must
//! be encoded using the `ConsensusEncodable` trait, since this data
//! must be the same for all systems. Any data going to the -user-, e.g.
//! over JSONRPC, should use the ordinary `Encodable` trait. (This
//! should also be the same across systems, of course, but has some
//! critical differences from the network format, e.g. scripts come
//! with an opcode decode, hashes are big-endian, numbers are typically
//! big-endian decimals, etc.)
//!
use std::collections::HashMap;
use std::hash::Hash;
use std::u32;
use util::hash::Sha256dHash;
use network::serialize::{SimpleDecoder, SimpleEncoder};
/// Data which can be encoded in a consensus-consistent way
pub trait ConsensusEncodable<S: SimpleEncoder> {
/// Encode an object with a well-defined format
fn consensus_encode(&self, e: &mut S) -> Result<(), S::Error>;
}
/// Data which can be encoded in a consensus-consistent way
pub trait ConsensusDecodable<D: SimpleDecoder> {
/// Decode an object with a well-defined format
fn consensus_decode(d: &mut D) -> Result<Self, D::Error>;
}
/// A variable-length unsigned integer
#[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Debug)]
pub struct VarInt(pub u64);
/// Data which must be preceded by a 4-byte checksum
#[derive(PartialEq, Eq, Clone, Debug)]
pub struct CheckedData(pub Vec<u8>);
// Primitive types
macro_rules! impl_int_encodable{
($ty:ident, $meth_dec:ident, $meth_enc:ident) => (
impl<D: SimpleDecoder> ConsensusDecodable<D> for $ty {
#[inline]
fn consensus_decode(d: &mut D) -> Result<$ty, D::Error> { d.$meth_dec().map($ty::from_le) }
}
impl<S: SimpleEncoder> ConsensusEncodable<S> for $ty {
#[inline]
fn consensus_encode(&self, s: &mut S) -> Result<(), S::Error> { s.$meth_enc(self.to_le()) }
}
)
}
impl_int_encodable!(u8, read_u8, emit_u8);
impl_int_encodable!(u16, read_u16, emit_u16);
impl_int_encodable!(u32, read_u32, emit_u32);
impl_int_encodable!(u64, read_u64, emit_u64);
impl_int_encodable!(i8, read_i8, emit_i8);
impl_int_encodable!(i16, read_i16, emit_i16);
impl_int_encodable!(i32, read_i32, emit_i32);
impl_int_encodable!(i64, read_i64, emit_i64);
impl<S: SimpleEncoder> ConsensusEncodable<S> for VarInt {
#[inline]
fn consensus_encode(&self, s: &mut S) -> Result<(), S::Error> {
match self.0 {
0...0xFC => { (self.0 as u8).consensus_encode(s) }
0xFD...0xFFFF => { try!(s.emit_u8(0xFD)); (self.0 as u16).consensus_encode(s) }
0x10000...0xFFFFFFFF => { try!(s.emit_u8(0xFE)); (self.0 as u32).consensus_encode(s) }
_ => { try!(s.emit_u8(0xFF)); (self.0 as u64).consensus_encode(s) }
}
}
}
impl<D: SimpleDecoder> ConsensusDecodable<D> for VarInt {
#[inline]
fn consensus_decode(d: &mut D) -> Result<VarInt, D::Error> {
let n = try!(d.read_u8());
match n {
0xFF => d.read_u64().map(|n| VarInt(u64::from_le(n))),
0xFE => d.read_u32().map(|n| VarInt(u32::from_le(n) as u64)),
0xFD => d.read_u16().map(|n| VarInt(u16::from_le(n) as u64)),
n => Ok(VarInt(n as u64))
}
}
}
// Booleans
impl<S: SimpleEncoder> ConsensusEncodable<S> for bool {
#[inline]
fn consensus_encode(&self, s: &mut S) -> Result<(), S::Error> { s.emit_u8(if *self {1} else {0}) }
}
impl<D: SimpleDecoder> ConsensusDecodable<D> for bool {
#[inline]
fn consensus_decode(d: &mut D) -> Result<bool, D::Error> { d.read_u8().map(|n| n != 0) }
}
// Strings
impl<S: SimpleEncoder> ConsensusEncodable<S> for String {
#[inline]
fn consensus_encode(&self, s: &mut S) -> Result<(), S::Error> {
self.as_bytes().consensus_encode(s)
}
}
impl<D: SimpleDecoder> ConsensusDecodable<D> for String {
#[inline]
fn consensus_decode(d: &mut D) -> Result<String, D::Error> {
String::from_utf8(try!(ConsensusDecodable::consensus_decode(d)))
.map_err(|_| d.error("String was not valid UTF8".to_string()))
}
}
// Arrays
macro_rules! impl_array {
( $size:expr ) => (
impl<S: SimpleEncoder, T: ConsensusEncodable<S>> ConsensusEncodable<S> for [T; $size] {
#[inline]
fn consensus_encode(&self, s: &mut S) -> Result<(), S::Error> {
for i in self.iter() { try!(i.consensus_encode(s)); }
Ok(())
}
}
impl<D: SimpleDecoder, T:ConsensusDecodable<D> + Copy> ConsensusDecodable<D> for [T; $size] {
#[inline]
fn consensus_decode(d: &mut D) -> Result<[T; $size], D::Error> {
// Set everything to the first decode
let mut ret = [try!(ConsensusDecodable::consensus_decode(d)); $size];
// Set the rest
for i in 1..$size { ret[i] = try!(ConsensusDecodable::consensus_decode(d)); }
Ok(ret)
}
}
);
}
impl_array!(2);
impl_array!(4);
impl_array!(8);
impl_array!(12);
impl_array!(16);
impl_array!(32);
impl<S: SimpleEncoder, T: ConsensusEncodable<S>> ConsensusEncodable<S> for [T] {
#[inline]
fn consensus_encode(&self, s: &mut S) -> Result<(), S::Error> {
try!(VarInt(self.len() as u64).consensus_encode(s));
for c in self.iter() { try!(c.consensus_encode(s)); }
Ok(())
}
}
// Cannot decode a slice
// Vectors
impl<S: SimpleEncoder, T: ConsensusEncodable<S>> ConsensusEncodable<S> for Vec<T> {
#[inline]
fn consensus_encode(&self, s: &mut S) -> Result<(), S::Error> { (&self[..]).consensus_encode(s) }
}
impl<D: SimpleDecoder, T: ConsensusDecodable<D>> ConsensusDecodable<D> for Vec<T> {
#[inline]
fn consensus_decode(d: &mut D) -> Result<Vec<T>, D::Error> {
let VarInt(len): VarInt = try!(ConsensusDecodable::consensus_decode(d));
let mut ret = Vec::with_capacity(len as usize);
for _ in 0..len { ret.push(try!(ConsensusDecodable::consensus_decode(d))); }
Ok(ret)
}
}
impl<S: SimpleEncoder, T: ConsensusEncodable<S>> ConsensusEncodable<S> for Box<[T]> {
#[inline]
fn consensus_encode(&self, s: &mut S) -> Result<(), S::Error> { (&self[..]).consensus_encode(s) }
}
impl<D: SimpleDecoder, T: ConsensusDecodable<D>> ConsensusDecodable<D> for Box<[T]> {
#[inline]
fn consensus_decode(d: &mut D) -> Result<Box<[T]>, D::Error> {
let VarInt(len): VarInt = try!(ConsensusDecodable::consensus_decode(d));
let len = len as usize;
let mut ret = Vec::with_capacity(len);
for _ in 0..len { ret.push(try!(ConsensusDecodable::consensus_decode(d))); }
Ok(ret.into_boxed_slice())
}
}
// Options (encoded as vectors of length 0 or 1)
impl<S: SimpleEncoder, T: ConsensusEncodable<S>> ConsensusEncodable<S> for Option<T> {
#[inline]
fn consensus_encode(&self, s: &mut S) -> Result<(), S::Error> {
match *self {
Some(ref data) => {
try!(1u8.consensus_encode(s));
try!(data.consensus_encode(s));
}
None => { try!(0u8.consensus_encode(s)); }
}
Ok(())
}
}
impl<D: SimpleDecoder, T:ConsensusDecodable<D>> ConsensusDecodable<D> for Option<T> {
#[inline]
fn consensus_decode(d: &mut D) -> Result<Option<T>, D::Error> {
let bit: u8 = try!(ConsensusDecodable::consensus_decode(d));
Ok(if bit != 0 {
Some(try!(ConsensusDecodable::consensus_decode(d)))
} else {
None
})
}
}
/// Do a double-SHA256 on some data and return the first 4 bytes
fn sha2_checksum(data: &[u8]) -> [u8; 4] {
let checksum = Sha256dHash::from_data(data);
[checksum[0], checksum[1], checksum[2], checksum[3]]
}
// Checked data
impl<S: SimpleEncoder> ConsensusEncodable<S> for CheckedData {
#[inline]
fn consensus_encode(&self, s: &mut S) -> Result<(), S::Error> {
try!((self.0.len() as u32).consensus_encode(s));
try!(sha2_checksum(&self.0).consensus_encode(s));
// We can't just pass to the slice encoder since it'll insert a length
for ch in self.0.iter() {
try!(ch.consensus_encode(s));
}
Ok(())
}
}
impl<D: SimpleDecoder> ConsensusDecodable<D> for CheckedData {
#[inline]
fn consensus_decode(d: &mut D) -> Result<CheckedData, D::Error> {
let len: u32 = try!(ConsensusDecodable::consensus_decode(d));
let checksum: [u8; 4] = try!(ConsensusDecodable::consensus_decode(d));
let mut ret = Vec::with_capacity(len as usize);
for _ in 0..len { ret.push(try!(ConsensusDecodable::consensus_decode(d))); }
let expected_checksum = sha2_checksum(&ret);
if expected_checksum != checksum {
Err(d.error(format!("bad checksum {:?} (expected {:?})", checksum, expected_checksum)))
} else {
Ok(CheckedData(ret))
}
}
}
// Tuples
macro_rules! tuple_encode {
($($x:ident),*) => (
impl <S: SimpleEncoder, $($x: ConsensusEncodable<S>),*> ConsensusEncodable<S> for ($($x),*) {
#[inline]
#[allow(non_snake_case)]
fn consensus_encode(&self, s: &mut S) -> Result<(), S::Error> {
let &($(ref $x),*) = self;
$( try!($x.consensus_encode(s)); )*
Ok(())
}
}
impl<D: SimpleDecoder, $($x: ConsensusDecodable<D>),*> ConsensusDecodable<D> for ($($x),*) {
#[inline]
#[allow(non_snake_case)]
fn consensus_decode(d: &mut D) -> Result<($($x),*), D::Error> {
Ok(($(try!({let $x = ConsensusDecodable::consensus_decode(d); $x })),*))
}
}
);
}
tuple_encode!(T0, T1);
tuple_encode!(T0, T1, T2, T3);
tuple_encode!(T0, T1, T2, T3, T4, T5);
tuple_encode!(T0, T1, T2, T3, T4, T5, T6, T7);
// References
impl<S: SimpleEncoder, T: ConsensusEncodable<S>> ConsensusEncodable<S> for Box<T> {
#[inline]
fn consensus_encode(&self, s: &mut S) -> Result<(), S::Error> { (**self).consensus_encode(s) }
}
impl<D: SimpleDecoder, T: ConsensusDecodable<D>> ConsensusDecodable<D> for Box<T> {
#[inline]
fn consensus_decode(d: &mut D) -> Result<Box<T>, D::Error> {
ConsensusDecodable::consensus_decode(d).map(|res| Box::new(res))
}
}
// HashMap
impl<S, K, V> ConsensusEncodable<S> for HashMap<K, V>
where S: SimpleEncoder,
K: ConsensusEncodable<S> + Eq + Hash,
V: ConsensusEncodable<S>
{
#[inline]
fn consensus_encode(&self, s: &mut S) -> Result<(), S::Error> {
try!(VarInt(self.len() as u64).consensus_encode(s));
for (key, value) in self.iter() {
try!(key.consensus_encode(s));
try!(value.consensus_encode(s));
}
Ok(())
}
}
impl<D, K, V> ConsensusDecodable<D> for HashMap<K, V>
where D: SimpleDecoder,
K: ConsensusDecodable<D> + Eq + Hash,
V: ConsensusDecodable<D>
{
#[inline]
fn consensus_decode(d: &mut D) -> Result<HashMap<K, V>, D::Error> {
let VarInt(len): VarInt = try!(ConsensusDecodable::consensus_decode(d));
let mut ret = HashMap::with_capacity(len as usize);
for _ in 0..len {
ret.insert(try!(ConsensusDecodable::consensus_decode(d)),
try!(ConsensusDecodable::consensus_decode(d)));
}
Ok(ret)
}
}
// Tests
#[cfg(test)]
mod tests {
use super::{CheckedData, VarInt};
use network::serialize::{deserialize, serialize};
#[test]
fn serialize_int_test() {
// bool
assert_eq!(serialize(&false).ok(), Some(vec![0u8]));
assert_eq!(serialize(&true).ok(), Some(vec![1u8]));
// u8
assert_eq!(serialize(&1u8).ok(), Some(vec![1u8]));
assert_eq!(serialize(&0u8).ok(), Some(vec![0u8]));
assert_eq!(serialize(&255u8).ok(), Some(vec![255u8]));
// u16
assert_eq!(serialize(&1u16).ok(), Some(vec![1u8, 0]));
assert_eq!(serialize(&256u16).ok(), Some(vec![0u8, 1]));
assert_eq!(serialize(&5000u16).ok(), Some(vec![136u8, 19]));
// u32
assert_eq!(serialize(&1u32).ok(), Some(vec![1u8, 0, 0, 0]));
assert_eq!(serialize(&256u32).ok(), Some(vec![0u8, 1, 0, 0]));
assert_eq!(serialize(&5000u32).ok(), Some(vec![136u8, 19, 0, 0]));
assert_eq!(serialize(&500000u32).ok(), Some(vec![32u8, 161, 7, 0]));
assert_eq!(serialize(&168430090u32).ok(), Some(vec![10u8, 10, 10, 10]));
// TODO: test negative numbers
assert_eq!(serialize(&1i32).ok(), Some(vec![1u8, 0, 0, 0]));
assert_eq!(serialize(&256i32).ok(), Some(vec![0u8, 1, 0, 0]));
assert_eq!(serialize(&5000i32).ok(), Some(vec![136u8, 19, 0, 0]));
assert_eq!(serialize(&500000i32).ok(), Some(vec![32u8, 161, 7, 0]));
assert_eq!(serialize(&168430090i32).ok(), Some(vec![10u8, 10, 10, 10]));
// u64
assert_eq!(serialize(&1u64).ok(), Some(vec![1u8, 0, 0, 0, 0, 0, 0, 0]));
assert_eq!(serialize(&256u64).ok(), Some(vec![0u8, 1, 0, 0, 0, 0, 0, 0]));
assert_eq!(serialize(&5000u64).ok(), Some(vec![136u8, 19, 0, 0, 0, 0, 0, 0]));
assert_eq!(serialize(&500000u64).ok(), Some(vec![32u8, 161, 7, 0, 0, 0, 0, 0]));
assert_eq!(serialize(&723401728380766730u64).ok(), Some(vec![10u8, 10, 10, 10, 10, 10, 10, 10]));
// TODO: test negative numbers
assert_eq!(serialize(&1i64).ok(), Some(vec![1u8, 0, 0, 0, 0, 0, 0, 0]));
assert_eq!(serialize(&256i64).ok(), Some(vec![0u8, 1, 0, 0, 0, 0, 0, 0]));
assert_eq!(serialize(&5000i64).ok(), Some(vec![136u8, 19, 0, 0, 0, 0, 0, 0]));
assert_eq!(serialize(&500000i64).ok(), Some(vec![32u8, 161, 7, 0, 0, 0, 0, 0]));
assert_eq!(serialize(&723401728380766730i64).ok(), Some(vec![10u8, 10, 10, 10, 10, 10, 10, 10]));
}
#[test]
fn serialize_varint_test() {
assert_eq!(serialize(&VarInt(10)).ok(), Some(vec![10u8]));
assert_eq!(serialize(&VarInt(0xFC)).ok(), Some(vec![0xFCu8]));
assert_eq!(serialize(&VarInt(0xFD)).ok(), Some(vec![0xFDu8, 0xFD, 0]));
assert_eq!(serialize(&VarInt(0xFFF)).ok(), Some(vec![0xFDu8, 0xFF, 0xF]));
assert_eq!(serialize(&VarInt(0xF0F0F0F)).ok(), Some(vec![0xFEu8, 0xF, 0xF, 0xF, 0xF]));
assert_eq!(serialize(&VarInt(0xF0F0F0F0F0E0)).ok(), Some(vec![0xFFu8, 0xE0, 0xF0, 0xF0, 0xF0, 0xF0, 0xF0, 0, 0]));
}
#[test]
fn serialize_checkeddata_test() {
let cd = CheckedData(vec![1u8, 2, 3, 4, 5]);
assert_eq!(serialize(&cd).ok(), Some(vec![5, 0, 0, 0, 162, 107, 175, 90, 1, 2, 3, 4, 5]));
}
#[test]
fn serialize_vector_test() {
assert_eq!(serialize(&vec![1u8, 2, 3]).ok(), Some(vec![3u8, 1, 2, 3]));
assert_eq!(serialize(&[1u8, 2, 3][..]).ok(), Some(vec![3u8, 1, 2, 3]));
// TODO: test vectors of more interesting objects
}
#[test]
fn serialize_strbuf_test() {
assert_eq!(serialize(&"Andrew".to_string()).ok(), Some(vec![6u8, 0x41, 0x6e, 0x64, 0x72, 0x65, 0x77]));
}
#[test]
fn serialize_box_test() {
assert_eq!(serialize(&Box::new(1u8)).ok(), Some(vec![1u8]));
assert_eq!(serialize(&Box::new(1u16)).ok(), Some(vec![1u8, 0]));
assert_eq!(serialize(&Box::new(1u64)).ok(), Some(vec![1u8, 0, 0, 0, 0, 0, 0, 0]));
}
#[test]
fn serialize_option_test() {
let none_ser = serialize(&None::<u8>);
let some_ser = serialize(&Some(0xFFu8));
assert_eq!(none_ser.ok(), Some(vec![0]));
assert_eq!(some_ser.ok(), Some(vec![1, 0xFF]));
}
#[test]
fn deserialize_int_test() {
// bool
assert_eq!(deserialize(&[58u8, 0]).ok(), Some(true));
assert_eq!(deserialize(&[58u8]).ok(), Some(true));
assert_eq!(deserialize(&[1u8]).ok(), Some(true));
assert_eq!(deserialize(&[0u8]).ok(), Some(false));
assert_eq!(deserialize(&[0u8, 1]).ok(), Some(false));
// u8
assert_eq!(deserialize(&[58u8]).ok(), Some(58u8));
// u16
assert_eq!(deserialize(&[0x01u8, 0x02]).ok(), Some(0x0201u16));
assert_eq!(deserialize(&[0xABu8, 0xCD]).ok(), Some(0xCDABu16));
assert_eq!(deserialize(&[0xA0u8, 0x0D]).ok(), Some(0xDA0u16));
let failure16: Result<u16, _> = deserialize(&[1u8]);
assert!(failure16.is_err());
// u32
assert_eq!(deserialize(&[0xABu8, 0xCD, 0, 0]).ok(), Some(0xCDABu32));
assert_eq!(deserialize(&[0xA0u8, 0x0D, 0xAB, 0xCD]).ok(), Some(0xCDAB0DA0u32));
let failure32: Result<u32, _> = deserialize(&[1u8, 2, 3]);
assert!(failure32.is_err());
// TODO: test negative numbers
assert_eq!(deserialize(&[0xABu8, 0xCD, 0, 0]).ok(), Some(0xCDABi32));
assert_eq!(deserialize(&[0xA0u8, 0x0D, 0xAB, 0x2D]).ok(), Some(0x2DAB0DA0i32));
let failurei32: Result<i32, _> = deserialize(&[1u8, 2, 3]);
assert!(failurei32.is_err());
// u64
assert_eq!(deserialize(&[0xABu8, 0xCD, 0, 0, 0, 0, 0, 0]).ok(), Some(0xCDABu64));
assert_eq!(deserialize(&[0xA0u8, 0x0D, 0xAB, 0xCD, 0x99, 0, 0, 0x99]).ok(), Some(0x99000099CDAB0DA0u64));
let failure64: Result<u64, _> = deserialize(&[1u8, 2, 3, 4, 5, 6, 7]);
assert!(failure64.is_err());
// TODO: test negative numbers
assert_eq!(deserialize(&[0xABu8, 0xCD, 0, 0, 0, 0, 0, 0]).ok(), Some(0xCDABi64));
assert_eq!(deserialize(&[0xA0u8, 0x0D, 0xAB, 0xCD, 0x99, 0, 0, 0x99]).ok(), Some(-0x66ffff663254f260i64));
let failurei64: Result<i64, _> = deserialize(&[1u8, 2, 3, 4, 5, 6, 7]);
assert!(failurei64.is_err());
}
#[test]
fn deserialize_vec_test() {
assert_eq!(deserialize(&[3u8, 2, 3, 4]).ok(), Some(vec![2u8, 3, 4]));
assert_eq!(deserialize(&[4u8, 2, 3, 4, 5, 6]).ok(), Some(vec![2u8, 3, 4, 5]));
}
#[test]
fn deserialize_strbuf_test() {
assert_eq!(deserialize(&[6u8, 0x41, 0x6e, 0x64, 0x72, 0x65, 0x77]).ok(), Some("Andrew".to_string()));
}
#[test]
fn deserialize_checkeddata_test() {
let cd: Result<CheckedData, _> = deserialize(&[5u8, 0, 0, 0, 162, 107, 175, 90, 1, 2, 3, 4, 5]);
assert_eq!(cd.ok(), Some(CheckedData(vec![1u8, 2, 3, 4, 5])));
}
#[test]
fn deserialize_option_test() {
let none: Result<Option<u8>, _> = deserialize(&[0u8]);
let good: Result<Option<u8>, _> = deserialize(&[1u8, 0xFF]);
let bad: Result<Option<u8>, _> = deserialize(&[2u8]);
assert!(bad.is_err());
assert_eq!(none.ok(), Some(None));
assert_eq!(good.ok(), Some(Some(0xFF)));
}
#[test]
fn deserialize_box_test() {
let zero: Result<Box<u8>, _> = deserialize(&[0u8]);
let one: Result<Box<u8>, _> = deserialize(&[1u8]);
assert_eq!(zero.ok(), Some(Box::new(0)));
assert_eq!(one.ok(), Some(Box::new(1)));
}
}