ceremonyclient/crates/vdf/src/proof_of_time.rs
Cassie Heart ebb31fd792 v1.4.19
2024-06-08 11:32:45 +00:00

89 lines
3.0 KiB
Rust

// Copyright 2018 Chia Network Inc and POA Networks Ltd.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use super::classgroup::ClassGroup;
use std::{collections::HashMap, usize};
pub fn serialize<V: ClassGroup>(proof: &[V], y: &V, int_size_bits: usize) -> Vec<u8> {
let proof_len = proof.len();
let element_length = 2 * ((int_size_bits + 16) >> 4);
let proof_len_in_bytes = (proof_len + 1) * element_length;
let mut v = vec![0; proof_len_in_bytes];
y.serialize(&mut v[0..element_length])
.expect(super::INCORRECT_BUFFER_SIZE);
for (index, group) in proof.iter().enumerate() {
let offset = (index + 1) * element_length;
group
.serialize(&mut v[offset..offset + element_length])
.expect(super::INCORRECT_BUFFER_SIZE)
}
v
}
pub fn deserialize_proof<T>(
proof_blob: &[u8],
discriminant: &T::BigNum,
orig_length: usize,
) -> Result<Vec<T>, ()>
where
T: ClassGroup,
for<'a, 'b> &'a T: std::ops::Mul<&'b T, Output = T>,
for<'a, 'b> &'a T::BigNum: std::ops::Mul<&'b T::BigNum, Output = T::BigNum>,
{
let length = T::size_in_bits(discriminant);
if length > usize::MAX - 16 {
return Err(());
}
let length = (length + 16) >> 4;
if length == 0 {
return Err(());
}
if orig_length != length {
return Err(());
}
let length = length * 2;
let proof_blob_length = proof_blob.len();
let rem = proof_blob_length % length;
if rem != 0 {
return Err(());
}
let proof_len = proof_blob_length / length;
let mut v = Vec::with_capacity(proof_len);
for i in 0..proof_len {
let offset = i * length;
v.push(T::from_bytes(
&proof_blob[offset..offset + length],
discriminant.clone(),
))
}
Ok(v)
}
pub fn iterate_squarings<V, U>(mut x: V, powers_to_calculate: U) -> HashMap<u64, V>
where
V: ClassGroup,
for<'a, 'b> &'a V: std::ops::Mul<&'b V, Output = V>,
for<'a, 'b> &'a V::BigNum: std::ops::Mul<&'b V::BigNum, Output = V::BigNum>,
U: Iterator<Item = u64>,
{
let mut powers_calculated = HashMap::new();
let mut powers_to_calculate: Vec<u64> = powers_to_calculate.collect();
powers_to_calculate.sort_unstable();
let mut previous_power: u64 = 0;
for &current_power in &powers_to_calculate {
x.repeated_square(current_power - previous_power);
powers_calculated.insert(current_power, x.clone());
previous_power = current_power
}
powers_calculated
}