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use crate::global;
use crate::pow::common::CuckooParams;
use crate::pow::error::{Error, ErrorKind};
use crate::pow::siphash::siphash_block;
use crate::pow::{PoWContext, Proof};
pub fn new_cuckaroom_ctx(edge_bits: u8, proof_size: usize) -> Result<Box<dyn PoWContext>, Error> {
let params = CuckooParams::new(edge_bits, edge_bits, proof_size)?;
Ok(Box::new(CuckaroomContext { params }))
}
pub struct CuckaroomContext {
params: CuckooParams,
}
impl PoWContext for CuckaroomContext {
fn set_header_nonce(
&mut self,
header: Vec<u8>,
nonce: Option<u32>,
_solve: bool,
) -> Result<(), Error> {
self.params.reset_header_nonce(header, nonce)
}
fn find_cycles(&mut self) -> Result<Vec<Proof>, Error> {
unimplemented!()
}
fn verify(&self, proof: &Proof) -> Result<(), Error> {
let size = proof.proof_size();
if size != global::proofsize() {
return Err(ErrorKind::Verification("wrong cycle length".to_owned()).into());
}
let nonces = &proof.nonces;
let mut from = vec![0u64; size];
let mut to = vec![0u64; size];
let mut xor_from: u64 = 0;
let mut xor_to: u64 = 0;
let mask = u64::MAX >> size.leading_zeros();
let mut head = vec![size; 1 + mask as usize];
let mut prev = vec![0usize; size];
for n in 0..size {
if nonces[n] > self.params.edge_mask {
return Err(ErrorKind::Verification("edge too big".to_owned()).into());
}
if n > 0 && nonces[n] <= nonces[n - 1] {
return Err(ErrorKind::Verification("edges not ascending".to_owned()).into());
}
let edge: u64 = siphash_block(&self.params.siphash_keys, nonces[n], 21, true);
let u = edge & self.params.node_mask;
let v = (edge >> 32) & self.params.node_mask;
from[n] = u;
let bits = (u & mask) as usize;
prev[n] = head[bits];
head[bits] = n;
to[n] = v;
xor_from ^= from[n];
xor_to ^= to[n];
}
if xor_from != xor_to {
return Err(ErrorKind::Verification("endpoints don't match up".to_owned()).into());
}
let mut visited = vec![false; size];
let mut n = 0;
let mut i = 0;
loop {
if visited[i] {
return Err(ErrorKind::Verification("branch in cycle".to_owned()).into());
}
visited[i] = true;
let mut k = head[(to[i] & mask) as usize];
loop {
if k == size {
return Err(ErrorKind::Verification("cycle dead ends".to_owned()).into());
}
if from[k] == to[i] {
break;
}
k = prev[k];
}
i = k;
n += 1;
if i == 0 {
break;
}
}
if n == size {
Ok(())
} else {
Err(ErrorKind::Verification("cycle too short".to_owned()).into())
}
}
}
#[cfg(test)]
mod test {
use super::*;
static V1_19_HASH: [u64; 4] = [
0xdb7896f799c76dab,
0x352e8bf25df7a723,
0xf0aa29cbb1150ea6,
0x3206c2759f41cbd5,
];
static V1_19_SOL: [u64; 42] = [
0x0413c, 0x05121, 0x0546e, 0x1293a, 0x1dd27, 0x1e13e, 0x1e1d2, 0x22870, 0x24642, 0x24833,
0x29190, 0x2a732, 0x2ccf6, 0x302cf, 0x32d9a, 0x33700, 0x33a20, 0x351d9, 0x3554b, 0x35a70,
0x376c1, 0x398c6, 0x3f404, 0x3ff0c, 0x48b26, 0x49a03, 0x4c555, 0x4dcda, 0x4dfcd, 0x4fbb6,
0x50275, 0x584a8, 0x5da0d, 0x5dbf1, 0x6038f, 0x66540, 0x72bbd, 0x77323, 0x77424, 0x77a14,
0x77dc9, 0x7d9dc,
];
static V2_29_HASH: [u64; 4] = [
0xe4b4a751f2eac47d,
0x3115d47edfb69267,
0x87de84146d9d609e,
0x7deb20eab6d976a1,
];
static V2_29_SOL: [u64; 42] = [
0x04acd28, 0x29ccf71, 0x2a5572b, 0x2f31c2c, 0x2f60c37, 0x317fe1d, 0x32f6d4c, 0x3f51227,
0x45ee1dc, 0x535eeb8, 0x5e135d5, 0x6184e3d, 0x6b1b8e0, 0x6f857a9, 0x8916a0f, 0x9beb5f8,
0xa3c8dc9, 0xa886d94, 0xaab6a57, 0xd6df8f8, 0xe4d630f, 0xe6ae422, 0xea2d658, 0xf7f369b,
0x10c465d8, 0x1130471e, 0x12049efb, 0x12f43bc5, 0x15b493a6, 0x16899354, 0x1915dfca,
0x195c3dac, 0x19b09ab6, 0x1a1a8ed7, 0x1bba748f, 0x1bdbf777, 0x1c806542, 0x1d201b53,
0x1d9e6af7, 0x1e99885e, 0x1f255834, 0x1f9c383b,
];
#[test]
fn cuckaroom19_29_vectors() {
global::set_local_chain_type(global::ChainTypes::Mainnet);
let mut ctx19 = new_impl(19, 42);
ctx19.params.siphash_keys = V1_19_HASH;
assert!(ctx19.verify(&Proof::new(V1_19_SOL.to_vec())).is_ok());
assert!(ctx19.verify(&Proof::zero(42)).is_err());
let mut ctx29 = new_impl(29, 42);
ctx29.params.siphash_keys = V2_29_HASH;
assert!(ctx29.verify(&Proof::new(V2_29_SOL.to_vec())).is_ok());
assert!(ctx29.verify(&Proof::zero(42)).is_err());
}
fn new_impl(edge_bits: u8, proof_size: usize) -> CuckaroomContext {
let params = CuckooParams::new(edge_bits, edge_bits, proof_size).unwrap();
CuckaroomContext { params }
}
}