From 67320849281e9a309e8591b474b3f2fd8cca4a01 Mon Sep 17 00:00:00 2001 From: Deirdre Connolly Date: Fri, 25 Sep 2020 00:13:35 -0400 Subject: [PATCH] Revert Sprout note commitment tree stuff for now --- zebra-chain/src/sprout/tree.rs | 169 --------------------------------- 1 file changed, 169 deletions(-) diff --git a/zebra-chain/src/sprout/tree.rs b/zebra-chain/src/sprout/tree.rs index 8e28f0ba..220e48ee 100644 --- a/zebra-chain/src/sprout/tree.rs +++ b/zebra-chain/src/sprout/tree.rs @@ -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::::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 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> for NoteCommitmentTree { - fn from(values: Vec) -> 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 -}