libzeropool/native/borsh/
boundednum.rs

1use crate::native::boundednum::*;
2use crate::fawkes_crypto::{
3    ff_uint::{Uint, PrimeField, Num, NumRepr},
4    borsh::{BorshDeserialize, BorshSerialize},
5    serde::{Serialize, Deserialize, Serializer, Deserializer, de},
6};
7use std::io::{Write, self};
8
9
10
11impl<Fr:PrimeField, const L: usize> BorshSerialize for BoundedNum<Fr, L> {
12    fn serialize<W: Write>(&self, writer: &mut W) -> io::Result<()> {
13        let n_limbs = (L - 1) / 8 + 1;
14        let w = writer.write(&self.0.try_to_vec().unwrap()[0..n_limbs])?;
15        if w!=n_limbs {
16            Err(io::Error::new(io::ErrorKind::Other, "Writer is broken"))
17        } else {
18            Ok(())
19        }
20    }
21}
22
23impl<Fr:PrimeField, const L: usize> BorshDeserialize for BoundedNum<Fr, L> {
24    fn deserialize(buf: &mut &[u8]) -> io::Result<Self> {
25        let n_limbs = (L - 1) / 8 + 1;
26        let n_limbs_total = Fr::Inner::NUM_WORDS*Fr::Inner::WORD_BITS/8;
27        let mut b = vec![0;n_limbs_total];
28        b[0..n_limbs].copy_from_slice(&buf[0..n_limbs]);
29        *buf = &buf[n_limbs..];
30        let n = Num::<Fr>::try_from_slice(&b)?;
31        Ok(Self(n))
32    }
33}
34
35impl<Fr:PrimeField, const L: usize> Serialize for BoundedNum<Fr, L> {
36    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
37        Serialize::serialize(&self.0, serializer)
38    }
39}
40
41impl<'de, Fr:PrimeField, const L: usize> Deserialize<'de> for BoundedNum<Fr, L> {
42    fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
43        let n: NumRepr<Fr::Inner> = Deserialize::deserialize(deserializer)?;
44        if n >= (NumRepr::ONE << L as u32) {
45            Err(de::Error::custom("Overflow"))
46        } else {
47            Ok(Self::new(Num::from_uint_unchecked(n)))
48        }
49
50    }
51}
libzeropool/native/borsh/boundednum.rs

libzeropool/native/borsh/
boundednum.rs
