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use crate::{
ark_std::string::ToString,
poseidon::sbox::PoseidonSbox,
utils::{from_field_elements, to_field_elements},
};
use ark_crypto_primitives::Error;
use ark_ff::{fields::PrimeField, BigInteger};
use ark_serialize::Read;
use ark_std::{error::Error as ArkError, rand::Rng, vec::Vec};
pub mod sbox;
#[derive(Debug)]
pub enum PoseidonError {
InvalidSboxSize(i8),
ApplySboxFailed,
InvalidInputs,
}
impl core::fmt::Display for PoseidonError {
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
use PoseidonError::*;
let msg = match self {
InvalidSboxSize(s) => format!("sbox is not supported: {}", s),
ApplySboxFailed => "failed to apply sbox".to_string(),
InvalidInputs => "invalid inputs".to_string(),
};
write!(f, "{}", msg)
}
}
impl ArkError for PoseidonError {}
#[derive(Default, Clone, Debug)]
pub struct PoseidonParameters<F: PrimeField> {
pub round_keys: Vec<F>,
pub mds_matrix: Vec<Vec<F>>,
pub full_rounds: u8,
pub partial_rounds: u8,
pub width: u8,
pub sbox: PoseidonSbox,
}
impl<F: PrimeField> PoseidonParameters<F> {
pub fn new(
round_keys: Vec<F>,
mds_matrix: Vec<Vec<F>>,
full_rounds: u8,
partial_rounds: u8,
width: u8,
sbox: PoseidonSbox,
) -> Self {
Self {
round_keys,
mds_matrix,
width,
full_rounds,
partial_rounds,
sbox,
}
}
pub fn generate<R: Rng>(_rng: &mut R) -> Self {
unimplemented!();
}
pub fn create_mds<R: Rng>(_rng: &mut R) -> Vec<Vec<F>> {
unimplemented!();
}
pub fn create_round_keys<R: Rng>(_rng: &mut R) -> Vec<F> {
unimplemented!();
}
pub fn to_bytes(&self) -> Vec<u8> {
let max_elt_size = F::BigInt::NUM_LIMBS * 8;
let mut buf: Vec<u8> = vec![];
let round_key_len = self.round_keys.len() * max_elt_size;
buf.extend(&self.width.to_be_bytes());
buf.extend(&self.full_rounds.to_be_bytes());
buf.extend(&self.partial_rounds.to_be_bytes());
buf.extend(&self.sbox.0.to_be_bytes());
buf.extend_from_slice(&(round_key_len as u32).to_be_bytes());
buf.extend_from_slice(&from_field_elements(&self.round_keys).unwrap());
let mut stored = false;
for i in 0..self.mds_matrix.len() {
if !stored {
let inner_vec_len = self.mds_matrix[i].len() * max_elt_size;
buf.extend_from_slice(&(inner_vec_len as u32).to_be_bytes());
stored = true;
}
buf.extend_from_slice(&from_field_elements(&self.mds_matrix[i]).unwrap());
}
buf
}
pub fn from_bytes(mut bytes: &[u8]) -> Result<Self, Error> {
let mut width_u8 = [0u8; 1];
bytes.read_exact(&mut width_u8)?;
let width = u8::from_be_bytes(width_u8);
let mut full_rounds_len = [0u8; 1];
bytes.read_exact(&mut full_rounds_len)?;
let full_rounds = u8::from_be_bytes(full_rounds_len);
let mut partial_rounds_u8 = [0u8; 1];
bytes.read_exact(&mut partial_rounds_u8)?;
let partial_rounds = u8::from_be_bytes(partial_rounds_u8);
let mut exponentiation_u8 = [0u8; 1];
bytes.read_exact(&mut exponentiation_u8)?;
let exp = i8::from_be_bytes(exponentiation_u8);
let mut round_key_len = [0u8; 4];
bytes.read_exact(&mut round_key_len)?;
let round_key_len_usize: usize = u32::from_be_bytes(round_key_len) as usize;
let mut round_keys_buf = vec![0u8; round_key_len_usize];
bytes.read_exact(&mut round_keys_buf)?;
let round_keys = to_field_elements::<F>(&round_keys_buf)?;
let mut mds_matrix_inner_vec_len = [0u8; 4];
bytes.read_exact(&mut mds_matrix_inner_vec_len)?;
let inner_vec_len_usize = u32::from_be_bytes(mds_matrix_inner_vec_len) as usize;
let mut mds_matrix: Vec<Vec<F>> = vec![];
while !bytes.is_empty() {
let mut inner_vec_buf = vec![0u8; inner_vec_len_usize];
bytes.read_exact(&mut inner_vec_buf)?;
let inner_vec = to_field_elements::<F>(&inner_vec_buf)?;
mds_matrix.push(inner_vec);
}
Ok(Self {
round_keys,
mds_matrix,
width,
full_rounds,
partial_rounds,
sbox: PoseidonSbox(exp),
})
}
}
#[cfg(all(test, feature = "poseidon_bn254_x5_5", feature = "poseidon_bn254_x5_3",))]
mod test {
use super::*;
use ark_ed_on_bn254::Fq;
use crate::utils::bn254_x5_3::get_poseidon_bn254_x5_3;
#[test]
fn test_parameter_to_and_from_bytes() {
let params = get_poseidon_bn254_x5_3::<Fq>();
let bytes = params.to_bytes();
let new_params: PoseidonParameters<Fq> = PoseidonParameters::from_bytes(&bytes).unwrap();
assert_eq!(bytes, new_params.to_bytes());
}
}