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updated `derive` for NoteType

This commit is contained in:
Paul 2022-05-19 15:30:40 +03:00
parent 48779d582f
commit 430e0473aa
2 changed files with 18 additions and 15 deletions
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1
src/constants/fixed_bases.rs
View File

@ -19,6 +19,7 @@ pub mod value_commit_v;
pub const ORCHARD_PERSONALIZATION: &str = "z.cash:Orchard";
/// SWU hash-to-curve personalization for the value commitment generator
/// TODO: should we change to "NOTE_TYPE_PERSONALIZATION"?
pub const VALUE_COMMITMENT_PERSONALIZATION: &str = "z.cash:Orchard-cv";
/// SWU hash-to-curve personalization for the note type generator

32
src/note/note_type.rs
View File

@ -1,23 +1,24 @@
use group::ff::PrimeField;
use halo2_proofs::arithmetic::CurveExt;
use pasta_curves::pallas;
use pasta_curves::{pallas};
use subtle::CtOption;
use crate::constants::fixed_bases::{VALUE_COMMITMENT_PERSONALIZATION, VALUE_COMMITMENT_V_BYTES};
use crate::keys::SpendValidatingKey;
use crate::spec::extract_p;
// use crate::keys::SpendValidatingKey;
/// Note type identifier.
#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
pub struct NoteType(pub(crate) pallas::Base);
// the hasher used to derive the assetID
#[allow(non_snake_case)]
fn assetID_hasher(msg: Vec<u8>) -> pallas::Base {
let hasher = pallas::Point::hash_to_curve(VALUE_COMMITMENT_PERSONALIZATION);
extract_p(&hasher(msg.as_bytes())))
}
impl NoteType {
/*
/// Generates a dummy note type for use as $\rho$ in dummy spent notes.
pub(crate) fn dummy(rng: &mut impl RngCore) -> Self {
NoteType(extract_p(&pallas::Point::random(rng)))
}
*/
/// Deserialize the note_type from a byte array.
pub fn from_bytes(bytes: &[u8; 32]) -> CtOption<Self> {
@ -35,18 +36,19 @@ impl NoteType {
///
/// [notetypes]: https://zips.z.cash/protocol/nu5.pdf#notetypes
#[allow(non_snake_case)]
pub(super) fn derive(asset_idx: u64) -> Self {
let hasher = pallas::Point::hash_to_curve(VALUE_COMMITMENT_PERSONALIZATION);
let V = hasher(&VALUE_COMMITMENT_V_BYTES);
pub(super) fn derive(ak: &SpendValidatingKey, assetDesc: &[u8; 64]) -> Self {
let mut s = vec![];
let value = pallas::Scalar::from(asset_idx);
s.extend_from_slice(&ak.to_bytes());
s.extend_from_slice(assetDesc);
NoteType(extract_p(&(V * value)))
NoteType(assetID_hasher(s))
}
/// note type for the "native" token (zec)
/// Note type for the "native" currency (zec), maintains backward compatibility with Orchard untyped notes.
#[allow(non_snake_case)]
pub fn native() -> Self {
Self::derive(1)
NoteType(assetID_hasher(VALUE_COMMITMENT_V_BYTES.to_vec()))
}
}