453 lines
16 KiB
Rust
453 lines
16 KiB
Rust
// Copyright 2015-2020 Parity Technologies (UK) Ltd.
|
|
// This file is part of OpenEthereum.
|
|
|
|
// OpenEthereum is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
|
|
// OpenEthereum is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU General Public License for more details.
|
|
|
|
// You should have received a copy of the GNU General Public License
|
|
// along with OpenEthereum. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
//! Ethash implementation
|
|
//! See https://github.com/ethereum/wiki/wiki/Ethash
|
|
|
|
// TODO: fix endianess for big endian
|
|
|
|
use cache::{NodeCache, NodeCacheBuilder};
|
|
use keccak::{keccak_256, keccak_512, H256};
|
|
use progpow::{generate_cdag, keccak_f800_long, keccak_f800_short, progpow, CDag};
|
|
use seed_compute::SeedHashCompute;
|
|
use shared::*;
|
|
use std::io;
|
|
|
|
use std::{mem, path::Path};
|
|
|
|
const MIX_WORDS: usize = ETHASH_MIX_BYTES / 4;
|
|
const MIX_NODES: usize = MIX_WORDS / NODE_WORDS;
|
|
pub const FNV_PRIME: u32 = 0x01000193;
|
|
|
|
/// Computation result
|
|
pub struct ProofOfWork {
|
|
/// Difficulty boundary
|
|
pub value: H256,
|
|
/// Mix
|
|
pub mix_hash: H256,
|
|
}
|
|
|
|
enum Algorithm {
|
|
Hashimoto,
|
|
Progpow(Box<CDag>),
|
|
}
|
|
|
|
pub struct Light {
|
|
block_number: u64,
|
|
cache: NodeCache,
|
|
algorithm: Algorithm,
|
|
}
|
|
|
|
/// Light cache structure
|
|
impl Light {
|
|
pub fn new_with_builder(
|
|
builder: &NodeCacheBuilder,
|
|
cache_dir: &Path,
|
|
block_number: u64,
|
|
progpow_transition: u64,
|
|
) -> Self {
|
|
let cache = builder.new_cache(cache_dir.to_path_buf(), block_number);
|
|
|
|
let algorithm = if block_number >= progpow_transition {
|
|
Algorithm::Progpow(Box::new(generate_cdag(cache.as_ref())))
|
|
} else {
|
|
Algorithm::Hashimoto
|
|
};
|
|
|
|
Light {
|
|
block_number,
|
|
cache,
|
|
algorithm,
|
|
}
|
|
}
|
|
|
|
/// Calculate the light boundary data
|
|
/// `header_hash` - The header hash to pack into the mix
|
|
/// `nonce` - The nonce to pack into the mix
|
|
pub fn compute(&self, header_hash: &H256, nonce: u64, block_number: u64) -> ProofOfWork {
|
|
match self.algorithm {
|
|
Algorithm::Progpow(ref c_dag) => {
|
|
let (value, mix_hash) = progpow(
|
|
*header_hash,
|
|
nonce,
|
|
block_number,
|
|
self.cache.as_ref(),
|
|
c_dag,
|
|
);
|
|
|
|
ProofOfWork { value, mix_hash }
|
|
}
|
|
Algorithm::Hashimoto => light_compute(self, header_hash, nonce),
|
|
}
|
|
}
|
|
|
|
pub fn from_file_with_builder(
|
|
builder: &NodeCacheBuilder,
|
|
cache_dir: &Path,
|
|
block_number: u64,
|
|
progpow_transition: u64,
|
|
) -> io::Result<Self> {
|
|
let cache = builder.from_file(cache_dir.to_path_buf(), block_number)?;
|
|
|
|
let algorithm = if block_number >= progpow_transition {
|
|
Algorithm::Progpow(Box::new(generate_cdag(cache.as_ref())))
|
|
} else {
|
|
Algorithm::Hashimoto
|
|
};
|
|
|
|
Ok(Light {
|
|
block_number,
|
|
cache,
|
|
algorithm,
|
|
})
|
|
}
|
|
|
|
pub fn to_file(&mut self) -> io::Result<&Path> {
|
|
self.cache.flush()?;
|
|
Ok(self.cache.cache_path())
|
|
}
|
|
}
|
|
|
|
pub fn slow_hash_block_number(block_number: u64) -> H256 {
|
|
SeedHashCompute::resume_compute_seedhash([0u8; 32], 0, block_number / ETHASH_EPOCH_LENGTH)
|
|
}
|
|
|
|
fn fnv_hash(x: u32, y: u32) -> u32 {
|
|
return x.wrapping_mul(FNV_PRIME) ^ y;
|
|
}
|
|
|
|
/// Difficulty quick check for POW preverification
|
|
///
|
|
/// `header_hash` The hash of the header
|
|
/// `nonce` The block's nonce
|
|
/// `mix_hash` The mix digest hash
|
|
/// Boundary recovered from mix hash
|
|
pub fn quick_get_difficulty(
|
|
header_hash: &H256,
|
|
nonce: u64,
|
|
mix_hash: &H256,
|
|
progpow: bool,
|
|
) -> H256 {
|
|
if progpow {
|
|
let seed = keccak_f800_short(*header_hash, nonce, [0u32; 8]);
|
|
keccak_f800_long(*header_hash, seed, unsafe { mem::transmute(*mix_hash) })
|
|
} else {
|
|
let mut buf = [0u8; 64 + 32];
|
|
|
|
let hash_len = header_hash.len();
|
|
buf[..hash_len].copy_from_slice(header_hash);
|
|
let end = hash_len + mem::size_of::<u64>();
|
|
buf[hash_len..end].copy_from_slice(&nonce.to_ne_bytes());
|
|
|
|
keccak_512::inplace_range(&mut buf, 0..end);
|
|
buf[64..].copy_from_slice(mix_hash);
|
|
|
|
let mut hash = [0u8; 32];
|
|
keccak_256::write(&buf, &mut hash);
|
|
|
|
hash
|
|
}
|
|
}
|
|
|
|
/// Calculate the light client data
|
|
/// `light` - The light client handler
|
|
/// `header_hash` - The header hash to pack into the mix
|
|
/// `nonce` - The nonce to pack into the mix
|
|
pub fn light_compute(light: &Light, header_hash: &H256, nonce: u64) -> ProofOfWork {
|
|
let full_size = get_data_size(light.block_number);
|
|
hash_compute(light, full_size, header_hash, nonce)
|
|
}
|
|
|
|
fn hash_compute(light: &Light, full_size: usize, header_hash: &H256, nonce: u64) -> ProofOfWork {
|
|
macro_rules! make_const_array {
|
|
($n:expr, $value:expr) => {{
|
|
// We use explicit lifetimes to ensure that val's borrow is invalidated until the
|
|
// transmuted val dies.
|
|
unsafe fn make_const_array<T, U>(val: &mut [T]) -> &mut [U; $n] {
|
|
use std::mem;
|
|
|
|
debug_assert_eq!(val.len() * mem::size_of::<T>(), $n * mem::size_of::<U>());
|
|
&mut *(val.as_mut_ptr() as *mut [U; $n])
|
|
}
|
|
|
|
make_const_array($value)
|
|
}};
|
|
}
|
|
|
|
#[repr(C)]
|
|
struct MixBuf {
|
|
half_mix: Node,
|
|
compress_bytes: [u8; MIX_WORDS],
|
|
}
|
|
|
|
if full_size % MIX_WORDS != 0 {
|
|
panic!("Unaligned full size");
|
|
}
|
|
|
|
// You may be asking yourself: what in the name of Crypto Jesus is going on here? So: we need
|
|
// `half_mix` and `compress_bytes` in a single array later down in the code (we hash them
|
|
// together to create `value`) so that we can hash the full array. However, we do a bunch of
|
|
// reading and writing to these variables first. We originally allocated two arrays and then
|
|
// stuck them together with `ptr::copy_nonoverlapping` at the end, but this method is
|
|
// _significantly_ faster - by my benchmarks, a consistent 3-5%. This is the most ridiculous
|
|
// optimization I have ever done and I am so sorry. I can only chalk it up to cache locality
|
|
// improvements, since I can't imagine that 3-5% of our runtime is taken up by catting two
|
|
// arrays together.
|
|
let mut buf: MixBuf = MixBuf {
|
|
half_mix: {
|
|
// Pack `header_hash` and `nonce` together
|
|
let mut out = [0u8; NODE_BYTES];
|
|
|
|
let hash_len = header_hash.len();
|
|
out[..hash_len].copy_from_slice(header_hash);
|
|
let end = hash_len + mem::size_of::<u64>();
|
|
out[hash_len..end].copy_from_slice(&nonce.to_ne_bytes());
|
|
|
|
// compute keccak-512 hash and replicate across mix
|
|
keccak_512::inplace_range(&mut out, 0..end);
|
|
|
|
Node { bytes: out }
|
|
},
|
|
compress_bytes: [0u8; MIX_WORDS],
|
|
};
|
|
|
|
let mut mix: [_; MIX_NODES] = [buf.half_mix.clone(), buf.half_mix.clone()];
|
|
|
|
let page_size = 4 * MIX_WORDS;
|
|
let num_full_pages = (full_size / page_size) as u32;
|
|
// deref once for better performance
|
|
let cache: &[Node] = light.cache.as_ref();
|
|
let first_val = buf.half_mix.as_words()[0];
|
|
|
|
debug_assert_eq!(MIX_NODES, 2);
|
|
debug_assert_eq!(NODE_WORDS, 16);
|
|
|
|
for i in 0..ETHASH_ACCESSES as u32 {
|
|
let index = {
|
|
// This is trivially safe, but does not work on big-endian. The safety of this is
|
|
// asserted in debug builds (see the definition of `make_const_array!`).
|
|
let mix_words: &mut [u32; MIX_WORDS] =
|
|
unsafe { make_const_array!(MIX_WORDS, &mut mix) };
|
|
|
|
fnv_hash(first_val ^ i, mix_words[i as usize % MIX_WORDS]) % num_full_pages
|
|
};
|
|
|
|
// MIX_NODES
|
|
for n in 0..2 {
|
|
let tmp_node = calculate_dag_item(index * MIX_NODES as u32 + n as u32, cache);
|
|
|
|
// NODE_WORDS
|
|
for (a, b) in mix[n].as_words_mut().iter_mut().zip(tmp_node.as_words()) {
|
|
*a = fnv_hash(*a, *b);
|
|
}
|
|
}
|
|
}
|
|
|
|
let mix_words: [u32; MIX_WORDS] = unsafe { mem::transmute(mix) };
|
|
|
|
{
|
|
// We iterate precisely `compress.len()` times and set each index,
|
|
// leaving the array fully initialized. THIS ONLY WORKS ON LITTLE-ENDIAN MACHINES.
|
|
// See a future PR to make this and the rest of the code work correctly on
|
|
// big-endian arches like mips.
|
|
let compress: &mut [u32; MIX_WORDS / 4] =
|
|
unsafe { make_const_array!(MIX_WORDS / 4, &mut buf.compress_bytes) };
|
|
#[cfg(target_endian = "big")]
|
|
{
|
|
compile_error!("OpenEthereum currently only supports little-endian targets");
|
|
}
|
|
|
|
// Compress mix
|
|
debug_assert_eq!(MIX_WORDS / 4, 8);
|
|
for i in 0..8 {
|
|
let w = i * 4;
|
|
|
|
let mut reduction = mix_words[w + 0];
|
|
reduction = reduction.wrapping_mul(FNV_PRIME) ^ mix_words[w + 1];
|
|
reduction = reduction.wrapping_mul(FNV_PRIME) ^ mix_words[w + 2];
|
|
reduction = reduction.wrapping_mul(FNV_PRIME) ^ mix_words[w + 3];
|
|
compress[i] = reduction;
|
|
}
|
|
}
|
|
|
|
let mix_hash = buf.compress_bytes;
|
|
|
|
let value: H256 = {
|
|
// We can interpret the buffer as an array of `u8`s, since it's `repr(C)`.
|
|
let read_ptr: *const u8 = &buf as *const MixBuf as *const u8;
|
|
let buffer = unsafe {
|
|
core::slice::from_raw_parts(
|
|
read_ptr,
|
|
buf.half_mix.bytes.len() + buf.compress_bytes.len(),
|
|
)
|
|
};
|
|
// We overwrite the buf.compress_bytes since `keccak_256` has an internal buffer and so allows
|
|
// overlapping arrays as input.
|
|
keccak_256::write(buffer, &mut buf.compress_bytes);
|
|
|
|
buf.compress_bytes
|
|
};
|
|
|
|
ProofOfWork { mix_hash, value }
|
|
}
|
|
|
|
// TODO: Use the `simd` crate
|
|
pub fn calculate_dag_item(node_index: u32, cache: &[Node]) -> Node {
|
|
let num_parent_nodes = cache.len();
|
|
let mut ret = cache[node_index as usize % num_parent_nodes].clone();
|
|
ret.as_words_mut()[0] ^= node_index;
|
|
|
|
keccak_512::inplace(ret.as_bytes_mut());
|
|
|
|
debug_assert_eq!(NODE_WORDS, 16);
|
|
for i in 0..ETHASH_DATASET_PARENTS as u32 {
|
|
let parent_index = fnv_hash(node_index ^ i, ret.as_words()[i as usize % NODE_WORDS])
|
|
% num_parent_nodes as u32;
|
|
let parent = &cache[parent_index as usize];
|
|
|
|
unroll! {
|
|
for w in 0..16 {
|
|
ret.as_words_mut()[w] = fnv_hash(ret.as_words()[w], parent.as_words()[w]);
|
|
}
|
|
}
|
|
}
|
|
|
|
keccak_512::inplace(ret.as_bytes_mut());
|
|
|
|
ret
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod test {
|
|
use super::*;
|
|
use std::fs;
|
|
use tempdir::TempDir;
|
|
|
|
#[test]
|
|
fn test_get_cache_size() {
|
|
// https://github.com/ethereum/wiki/wiki/Ethash/ef6b93f9596746a088ea95d01ca2778be43ae68f#data-sizes
|
|
assert_eq!(16776896usize, get_cache_size(0));
|
|
assert_eq!(16776896usize, get_cache_size(1));
|
|
assert_eq!(16776896usize, get_cache_size(ETHASH_EPOCH_LENGTH - 1));
|
|
assert_eq!(16907456usize, get_cache_size(ETHASH_EPOCH_LENGTH));
|
|
assert_eq!(16907456usize, get_cache_size(ETHASH_EPOCH_LENGTH + 1));
|
|
assert_eq!(284950208usize, get_cache_size(2046 * ETHASH_EPOCH_LENGTH));
|
|
assert_eq!(285081536usize, get_cache_size(2047 * ETHASH_EPOCH_LENGTH));
|
|
assert_eq!(
|
|
285081536usize,
|
|
get_cache_size(2048 * ETHASH_EPOCH_LENGTH - 1)
|
|
);
|
|
}
|
|
|
|
#[test]
|
|
fn test_get_data_size() {
|
|
// https://github.com/ethereum/wiki/wiki/Ethash/ef6b93f9596746a088ea95d01ca2778be43ae68f#data-sizes
|
|
assert_eq!(1073739904usize, get_data_size(0));
|
|
assert_eq!(1073739904usize, get_data_size(1));
|
|
assert_eq!(1073739904usize, get_data_size(ETHASH_EPOCH_LENGTH - 1));
|
|
assert_eq!(1082130304usize, get_data_size(ETHASH_EPOCH_LENGTH));
|
|
assert_eq!(1082130304usize, get_data_size(ETHASH_EPOCH_LENGTH + 1));
|
|
assert_eq!(18236833408usize, get_data_size(2046 * ETHASH_EPOCH_LENGTH));
|
|
assert_eq!(18245220736usize, get_data_size(2047 * ETHASH_EPOCH_LENGTH));
|
|
}
|
|
|
|
#[test]
|
|
fn test_difficulty_test() {
|
|
let hash = [
|
|
0xf5, 0x7e, 0x6f, 0x3a, 0xcf, 0xc0, 0xdd, 0x4b, 0x5b, 0xf2, 0xbe, 0xe4, 0x0a, 0xb3,
|
|
0x35, 0x8a, 0xa6, 0x87, 0x73, 0xa8, 0xd0, 0x9f, 0x5e, 0x59, 0x5e, 0xab, 0x55, 0x94,
|
|
0x05, 0x52, 0x7d, 0x72,
|
|
];
|
|
let mix_hash = [
|
|
0x1f, 0xff, 0x04, 0xce, 0xc9, 0x41, 0x73, 0xfd, 0x59, 0x1e, 0x3d, 0x89, 0x60, 0xce,
|
|
0x6b, 0xdf, 0x8b, 0x19, 0x71, 0x04, 0x8c, 0x71, 0xff, 0x93, 0x7b, 0xb2, 0xd3, 0x2a,
|
|
0x64, 0x31, 0xab, 0x6d,
|
|
];
|
|
let nonce = 0xd7b3ac70a301a249;
|
|
let boundary_good = [
|
|
0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x3e, 0x9b, 0x6c, 0x69, 0xbc, 0x2c, 0xe2, 0xa2,
|
|
0x4a, 0x8e, 0x95, 0x69, 0xef, 0xc7, 0xd7, 0x1b, 0x33, 0x35, 0xdf, 0x36, 0x8c, 0x9a,
|
|
0xe9, 0x7e, 0x53, 0x84,
|
|
];
|
|
assert_eq!(
|
|
quick_get_difficulty(&hash, nonce, &mix_hash, false)[..],
|
|
boundary_good[..]
|
|
);
|
|
let boundary_bad = [
|
|
0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x3a, 0x9b, 0x6c, 0x69, 0xbc, 0x2c, 0xe2, 0xa2,
|
|
0x4a, 0x8e, 0x95, 0x69, 0xef, 0xc7, 0xd7, 0x1b, 0x33, 0x35, 0xdf, 0x36, 0x8c, 0x9a,
|
|
0xe9, 0x7e, 0x53, 0x84,
|
|
];
|
|
assert!(quick_get_difficulty(&hash, nonce, &mix_hash, false)[..] != boundary_bad[..]);
|
|
}
|
|
|
|
#[test]
|
|
fn test_light_compute() {
|
|
let hash = [
|
|
0xf5, 0x7e, 0x6f, 0x3a, 0xcf, 0xc0, 0xdd, 0x4b, 0x5b, 0xf2, 0xbe, 0xe4, 0x0a, 0xb3,
|
|
0x35, 0x8a, 0xa6, 0x87, 0x73, 0xa8, 0xd0, 0x9f, 0x5e, 0x59, 0x5e, 0xab, 0x55, 0x94,
|
|
0x05, 0x52, 0x7d, 0x72,
|
|
];
|
|
let mix_hash = [
|
|
0x1f, 0xff, 0x04, 0xce, 0xc9, 0x41, 0x73, 0xfd, 0x59, 0x1e, 0x3d, 0x89, 0x60, 0xce,
|
|
0x6b, 0xdf, 0x8b, 0x19, 0x71, 0x04, 0x8c, 0x71, 0xff, 0x93, 0x7b, 0xb2, 0xd3, 0x2a,
|
|
0x64, 0x31, 0xab, 0x6d,
|
|
];
|
|
let boundary = [
|
|
0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x3e, 0x9b, 0x6c, 0x69, 0xbc, 0x2c, 0xe2, 0xa2,
|
|
0x4a, 0x8e, 0x95, 0x69, 0xef, 0xc7, 0xd7, 0x1b, 0x33, 0x35, 0xdf, 0x36, 0x8c, 0x9a,
|
|
0xe9, 0x7e, 0x53, 0x84,
|
|
];
|
|
let nonce = 0xd7b3ac70a301a249;
|
|
|
|
let tempdir = TempDir::new("").unwrap();
|
|
// difficulty = 0x085657254bd9u64;
|
|
let light = NodeCacheBuilder::new(None, u64::max_value()).light(tempdir.path(), 486382);
|
|
let result = light_compute(&light, &hash, nonce);
|
|
assert_eq!(result.mix_hash[..], mix_hash[..]);
|
|
assert_eq!(result.value[..], boundary[..]);
|
|
}
|
|
|
|
#[test]
|
|
fn test_drop_old_data() {
|
|
let tempdir = TempDir::new("").unwrap();
|
|
let builder = NodeCacheBuilder::new(None, u64::max_value());
|
|
let first = builder
|
|
.light(tempdir.path(), 0)
|
|
.to_file()
|
|
.unwrap()
|
|
.to_owned();
|
|
|
|
let second = builder
|
|
.light(tempdir.path(), ETHASH_EPOCH_LENGTH)
|
|
.to_file()
|
|
.unwrap()
|
|
.to_owned();
|
|
assert!(fs::metadata(&first).is_ok());
|
|
|
|
let _ = builder
|
|
.light(tempdir.path(), ETHASH_EPOCH_LENGTH * 2)
|
|
.to_file();
|
|
assert!(fs::metadata(&first).is_err());
|
|
assert!(fs::metadata(&second).is_ok());
|
|
|
|
let _ = builder
|
|
.light(tempdir.path(), ETHASH_EPOCH_LENGTH * 3)
|
|
.to_file();
|
|
assert!(fs::metadata(&second).is_err());
|
|
}
|
|
}
|