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Revert Sprout note commitment tree stuff for now

This commit is contained in:
Deirdre Connolly 2020-09-25 00:13:35 -04:00 committed by Deirdre Connolly
parent fea448227f
commit 6732084928
1 changed files with 0 additions and 169 deletions
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169
zebra-chain/src/sprout/tree.rs
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@ -10,65 +10,11 @@
//!
//! A root of a note commitment tree is associated with each treestate.
#![allow(clippy::unit_arg)]
#![allow(dead_code)]
use std::fmt;
use byteorder::{ByteOrder, LittleEndian};
use lazy_static::lazy_static;
#[cfg(any(test, feature = "proptest-impl"))]
use proptest_derive::Arbitrary;
use sha2::digest::generic_array::{typenum::U64, GenericArray};
use super::commitment::NoteCommitment;
const MERKLE_DEPTH: usize = 29;
/// MerkleCRH^Sprout Hash Function
///
/// MerkleCRH^Sprout(layer, left, right) := SHA256Compress(left || right)
///
/// `layer` is unused for Sprout but used for the Sapling equivalent.
///
/// https://zips.z.cash/protocol/protocol.pdf#merklecrh
fn merkle_crh_sprout(left: [u8; 32], right: [u8; 32]) -> [u8; 32] {
let mut state = [0u32; 8];
let mut block = GenericArray::<u8, U64>::default();
block.as_mut_slice()[0..32].copy_from_slice(&left[..]);
block.as_mut_slice()[32..64].copy_from_slice(&right[..]);
sha2::compress256(&mut state, &[block]);
let mut derived_bytes = [0u8; 32];
LittleEndian::write_u32_into(&state, &mut derived_bytes);
derived_bytes
}
lazy_static! {
/// Sprout note commitment trees have a max depth of 29.
///
/// https://zips.z.cash/protocol/canopy.pdf#constants
static ref EMPTY_ROOTS: Vec<[u8; 32]> = {
// Uncommitted^Sprout = = [0]^l_MerkleSprout
let mut v = vec![[0u8; 32]];
for d in 0..MERKLE_DEPTH {
let next = merkle_crh_sprout(v[d], v[d]);
v.push(next);
}
v
};
}
/// The index of a note’s commitment at the leafmost layer of its Note
/// Commitment Tree.
///
/// https://zips.z.cash/protocol/protocol.pdf#merkletree
pub struct Position(pub(crate) u64);
/// Sprout note commitment tree root node hash.
///
@ -97,118 +43,3 @@ impl From<Root> for [u8; 32] {
rt.0
}
}
/// Sprout Note Commitment Tree
#[derive(Clone, Debug, Default, Eq, PartialEq)]
#[cfg_attr(test, derive(Arbitrary))]
struct NoteCommitmentTree {
/// The root node of the tree (often used as an anchor).
root: Root,
/// The height of the tree (maximum height for Sprout is 29).
height: u8,
/// The number of leaves (note commitments) in this tree.
count: u32,
}
impl From<Vec<NoteCommitment>> for NoteCommitmentTree {
fn from(values: Vec<NoteCommitment>) -> Self {
if values.is_empty() {
return NoteCommitmentTree {
root: Root::default(),
height: 0,
count: 0,
};
}
let count = values.len() as u32;
let mut height = 0u8;
let mut current_layer: Vec<[u8; 32]> = values.into_iter().map(|cm| cm.into()).collect();
while usize::from(height) < MERKLE_DEPTH {
let mut next_layer_up = vec![];
while !current_layer.is_empty() {
let left = current_layer.remove(0);
let right;
if current_layer.is_empty() {
right = EMPTY_ROOTS[height as usize];
} else {
right = current_layer.remove(0);
}
next_layer_up.push(merkle_crh_sprout(left, right));
}
height += 1;
current_layer = next_layer_up;
}
assert!(current_layer.len() == 1);
NoteCommitmentTree {
root: Root(current_layer.remove(0)),
height,
count,
}
}
}
impl NoteCommitmentTree {
/// Get the Jubjub-based Pedersen hash of root node of this merkle tree of
/// commitment notes.
pub fn hash(&self) -> [u8; 32] {
self.root.0
}
}
#[cfg(test)]
mod tests {
use super::*;
// XXX: Computed these myself, not sure if they're correct.
//
// TODO: pull these in with bytes reversed:
// https://github.com/zcash/zcash/blob/master/src/test/data/merkle_roots.json
const HEX_EMPTY_ROOTS: [&str; 30] = [
"0000000000000000000000000000000000000000000000000000000000000000",
"1416a57ca83b5c422fdd54cee70a02c2d174e5b60f6d1398cc267eaea6e70bbf",
"8e595d8337af9321e04f70caea0eb95a87ecea7c8075e027ccf38d99995e9ccb",
"0ed30a29eb7464122b5a1497b9b9ac5e32c7b1e8b27cd3fcbf0addee5552a7dd",
"9830b6c3261a9a9af3e706234794e3daa20f7d09b2c185553e777169274758f7",
"949fe462a5bb6b35071f5c05f1b2d623c11bf8306816b24cb6c7efb5d96bf920",
"021174939ba7450ed5bf8694362205fdf85bfbe617d2ad4b7ef103e45eebdaa4",
"1b5db558fbe8b50aaef1be056a3f23980395635180c73ab1da8afa3329ef32c9",
"b77cae0af63b4a239c830ee116373523cb5008f1f3b03c6e7c346e5c8f97fa3d",
"86475c6708c9f1f5b4688b4c31723874e9d714890bb1b422519887c85c90b410",
"d7365f73b4d33b00ed3cd55dbb638dd7801ae5d7323e957a06b9a2691563e748",
"288049b23c01d1acf83a15e3fd1e19ec6cb4a550bc9e00305096a67e93dc001c",
"20258febd62395043264fd2d5bf0e849fe74f4ae49dd8765630e9cde200e37a2",
"2b9d0c9e7d8f5ca38175f2d40cd059a0dda76d7b0408ad27f6bec3d93ea2d0ce",
"89be2f7d2c0e7c487578aeb3c5434042edeb30f31727c7699c33a6662fae96bc",
"7d10d2153404df9762efa3c4796f67483a253577717a4bbefbef0b9c50a9283b",
"18c0d669ce9cf39b86e10a8c17f580faeca5894dee5f8c444bb7c7307bd94625",
"6855202bad86070cb0f1f8d69b0a757d365dfa57cd5f50e7003b470aa363a3f7",
"3bf276545ddb5660752b22dbacea87495ecd77bedac75452673a56b319090a67",
"9af95f9f3e6b2db4b159490b5c2e49b868b2c927cf3bedd7e787a635173e1195",
"508f30499fb8d6682b4a743f2aa2a0ea2d37b55d8033c888ff6ab543f0332430",
"9a16a3c6883170fee9d27f372b1dafb4c98911949e0e2cf8e748a56ff0bbc30c",
"a691f83055fa4ab4be344eb7455a20cd7a54dc84159869564f2622a6ea139d69",
"7e3ad117fb8cacf4d3cbb4416dda6bdc3a048cef02743dbee598a2c6593b2fd3",
"8e9a5f34f491326caa1e2ca6de200d39d5c8aabe8e07f022a81449aa49051f8a",
"a8bc7bfa549f88994f4a6b4dde74c1ceb9723f0da40ceab558a39640f6a503fc",
"be36d79c79d4968c1ddc81c6ed398e6c99f2490c2d0b915f63f83463be6c148b",
"eefb051a4ae623dec48e3368f4f877af771ae04b91011d4956bbc5bc03ae6260",
"fcb9aac1104f3cbcc4da853dd8bee0faf4b4d47079147dbaaf31530e077da089",
"25136bcbdfc1066ad6a942242ee0ae3ca3ccdc53b68d393f682734241622498d",
];
#[test]
fn empty_roots() {
for i in 0..EMPTY_ROOTS.len() {
assert_eq!(hex::encode(EMPTY_ROOTS[i]), HEX_EMPTY_ROOTS[i]);
}
}
// TODO: pull these in with bytes reversed:
// https://github.com/zcash/zcash/blob/master/src/test/data/merkle_commitments.json
}