lighthouse/crypto/kzg/src/kzg_proof.rs
2023-01-12 14:17:14 -05:00

138 lines
3.7 KiB
Rust

use serde::de::{Deserialize, Deserializer};
use serde::ser::{Serialize, Serializer};
use ssz_derive::{Decode, Encode};
use std::fmt;
use std::fmt::Debug;
use std::str::FromStr;
use tree_hash::{PackedEncoding, TreeHash};
const KZG_PROOF_BYTES_LEN: usize = 48;
#[derive(PartialEq, Hash, Clone, Copy, Encode, Decode)]
#[ssz(struct_behaviour = "transparent")]
pub struct KzgProof(pub [u8; KZG_PROOF_BYTES_LEN]);
impl KzgProof {
pub fn empty() -> Self {
let mut bytes = [0; KZG_PROOF_BYTES_LEN];
bytes[0] = 192;
Self(bytes)
}
}
impl fmt::Display for KzgProof {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}", eth2_serde_utils::hex::encode(self.0))
}
}
impl Default for KzgProof {
fn default() -> Self {
KzgProof([0; KZG_PROOF_BYTES_LEN])
}
}
impl From<[u8; KZG_PROOF_BYTES_LEN]> for KzgProof {
fn from(bytes: [u8; KZG_PROOF_BYTES_LEN]) -> Self {
Self(bytes)
}
}
impl Into<[u8; KZG_PROOF_BYTES_LEN]> for KzgProof {
fn into(self) -> [u8; KZG_PROOF_BYTES_LEN] {
self.0
}
}
impl TreeHash for KzgProof {
fn tree_hash_type() -> tree_hash::TreeHashType {
<[u8; KZG_PROOF_BYTES_LEN]>::tree_hash_type()
}
fn tree_hash_packed_encoding(&self) -> PackedEncoding {
self.0.tree_hash_packed_encoding()
}
fn tree_hash_packing_factor() -> usize {
<[u8; KZG_PROOF_BYTES_LEN]>::tree_hash_packing_factor()
}
fn tree_hash_root(&self) -> tree_hash::Hash256 {
self.0.tree_hash_root()
}
}
impl Serialize for KzgProof {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
serializer.serialize_str(&self.to_string())
}
}
impl<'de> Deserialize<'de> for KzgProof {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
pub struct StringVisitor;
impl<'de> serde::de::Visitor<'de> for StringVisitor {
type Value = String;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("a hex string with 0x prefix")
}
fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
Ok(value.to_string())
}
}
let string = deserializer.deserialize_str(StringVisitor)?;
<Self as std::str::FromStr>::from_str(&string).map_err(serde::de::Error::custom)
}
}
impl FromStr for KzgProof {
type Err = String;
fn from_str(s: &str) -> Result<Self, Self::Err> {
if let Some(stripped) = s.strip_prefix("0x") {
let bytes = hex::decode(stripped).map_err(|e| e.to_string())?;
if bytes.len() == KZG_PROOF_BYTES_LEN {
let mut kzg_proof_bytes = [0; KZG_PROOF_BYTES_LEN];
kzg_proof_bytes[..].copy_from_slice(&bytes);
Ok(Self(kzg_proof_bytes))
} else {
Err(format!(
"InvalidByteLength: got {}, expected {}",
bytes.len(),
KZG_PROOF_BYTES_LEN
))
}
} else {
Err("must start with 0x".to_string())
}
}
}
impl Debug for KzgProof {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}", eth2_serde_utils::hex::encode(&self.0))
}
}
#[cfg(feature = "arbitrary")]
impl arbitrary::Arbitrary<'_> for KzgProof {
fn arbitrary(u: &mut arbitrary::Unstructured<'_>) -> arbitrary::Result<Self> {
let mut bytes = [0u8; KZG_PROOF_BYTES_LEN];
u.fill_buffer(&mut bytes)?;
Ok(KzgProof(bytes))
}
}