lighthouse/eth2/utils/bls/src/public_key.rs
2019-03-15 13:31:30 +11:00

139 lines
4.1 KiB
Rust

use super::SecretKey;
use bls_aggregates::PublicKey as RawPublicKey;
use serde::de::{Deserialize, Deserializer};
use serde::ser::{Serialize, Serializer};
use serde_hex::{encode as hex_encode, PrefixedHexVisitor};
use ssz::{
decode_ssz_list, hash, ssz_encode, Decodable, DecodeError, Encodable, SszStream, TreeHash,
};
use std::default;
use std::hash::{Hash, Hasher};
/// A single BLS signature.
///
/// This struct is a wrapper upon a base type and provides helper functions (e.g., SSZ
/// serialization).
#[derive(Debug, Clone, Eq)]
pub struct PublicKey(RawPublicKey);
impl PublicKey {
pub fn from_secret_key(secret_key: &SecretKey) -> Self {
PublicKey(RawPublicKey::from_secret_key(secret_key.as_raw()))
}
/// Returns the underlying signature.
pub fn as_raw(&self) -> &RawPublicKey {
&self.0
}
/// Converts compressed bytes to PublicKey
pub fn from_bytes(bytes: &[u8]) -> Result<Self, DecodeError> {
let pubkey = RawPublicKey::from_bytes(&bytes).map_err(|_| DecodeError::Invalid)?;
Ok(PublicKey(pubkey))
}
/// Returns the PublicKey as (x, y) bytes
pub fn as_uncompressed_bytes(&self) -> Vec<u8> {
RawPublicKey::as_uncompressed_bytes(&mut self.0.clone())
}
/// Converts (x, y) bytes to PublicKey
pub fn from_uncompressed_bytes(bytes: &[u8]) -> Result<Self, DecodeError> {
let pubkey =
RawPublicKey::from_uncompressed_bytes(&bytes).map_err(|_| DecodeError::Invalid)?;
Ok(PublicKey(pubkey))
}
/// Returns the last 6 bytes of the SSZ encoding of the public key, as a hex string.
///
/// Useful for providing a short identifier to the user.
pub fn concatenated_hex_id(&self) -> String {
let bytes = ssz_encode(self);
let end_bytes = &bytes[bytes.len().saturating_sub(6)..bytes.len()];
hex_encode(end_bytes)
}
}
impl default::Default for PublicKey {
fn default() -> Self {
let secret_key = SecretKey::random();
PublicKey::from_secret_key(&secret_key)
}
}
impl Encodable for PublicKey {
fn ssz_append(&self, s: &mut SszStream) {
s.append_vec(&self.0.as_bytes());
}
}
impl Decodable for PublicKey {
fn ssz_decode(bytes: &[u8], i: usize) -> Result<(Self, usize), DecodeError> {
let (sig_bytes, i) = decode_ssz_list(bytes, i)?;
let raw_sig = RawPublicKey::from_bytes(&sig_bytes).map_err(|_| DecodeError::TooShort)?;
Ok((PublicKey(raw_sig), i))
}
}
impl Serialize for PublicKey {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
serializer.serialize_str(&hex_encode(self.as_raw().as_bytes()))
}
}
impl<'de> Deserialize<'de> for PublicKey {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
let bytes = deserializer.deserialize_str(PrefixedHexVisitor)?;
let obj = PublicKey::from_bytes(&bytes[..])
.map_err(|e| serde::de::Error::custom(format!("invalid pubkey ({:?})", e)))?;
Ok(obj)
}
}
impl TreeHash for PublicKey {
fn hash_tree_root(&self) -> Vec<u8> {
hash(&self.0.as_bytes())
}
}
impl PartialEq for PublicKey {
fn eq(&self, other: &PublicKey) -> bool {
ssz_encode(self) == ssz_encode(other)
}
}
impl Hash for PublicKey {
/// Note: this is distinct from consensus serialization, it will produce a different hash.
///
/// This method uses the uncompressed bytes, which are much faster to obtain than the
/// compressed bytes required for consensus serialization.
///
/// Use `ssz::Encode` to obtain the bytes required for consensus hashing.
fn hash<H: Hasher>(&self, state: &mut H) {
self.as_uncompressed_bytes().hash(state)
}
}
#[cfg(test)]
mod tests {
use super::*;
use ssz::ssz_encode;
#[test]
pub fn test_ssz_round_trip() {
let sk = SecretKey::random();
let original = PublicKey::from_secret_key(&sk);
let bytes = ssz_encode(&original);
let (decoded, _) = PublicKey::ssz_decode(&bytes, 0).unwrap();
assert_eq!(original, decoded);
}
}