72 lines
2.4 KiB
Rust
72 lines
2.4 KiB
Rust
//! Note Commitment Trees.
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//!
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//! A note commitment tree is an incremental Merkle tree of fixed depth
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//! used to store note commitments that JoinSplit transfers or Spend
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//! transfers produce. Just as the unspent transaction output set (UTXO
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//! set) used in Bitcoin, it is used to express the existence of value and
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//! the capability to spend it. However, unlike the UTXO set, it is not
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//! the job of this tree to protect against double-spending, as it is
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//! append-only.
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//!
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//! A root of a note commitment tree is associated with each treestate.
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use std::io;
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#[cfg(test)]
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use proptest_derive::Arbitrary;
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use crate::serialization::{SerializationError, ZcashDeserialize, ZcashSerialize};
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// XXX: Depending on if we implement SproutNoteCommitmentTree or
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// similar, it may be worth it to define a NoteCommitmentTree trait.
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/// Sapling Note Commitment Tree
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#[derive(Clone, Debug, Default, Eq, PartialEq)]
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#[cfg_attr(test, derive(Arbitrary))]
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pub struct SaplingNoteCommitmentTree;
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/// Sapling note commitment tree root node hash.
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///
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/// The root hash in LEBS2OSP256(rt) encoding of the Sapling note
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/// commitment tree corresponding to the final Sapling treestate of
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/// this block. A root of a note commitment tree is associated with
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/// each treestate.
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#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
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#[cfg_attr(test, derive(Arbitrary))]
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pub struct SaplingNoteTreeRootHash(pub [u8; 32]);
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impl From<SaplingNoteCommitmentTree> for SaplingNoteTreeRootHash {
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fn from(_tree: SaplingNoteCommitmentTree) -> Self {
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// TODO: The Sapling note commitment tree requires a Pedersen
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// hash function, not SHA256.
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// let mut hash_writer = Sha256dWriter::default();
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// sapling_note_commitment_tree
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// .zcash_serialize(&mut hash_writer)
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// .expect("A Sapling note committment tree must serialize.");
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// Self(hash_writer.finish())
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unimplemented!();
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}
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}
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impl SaplingNoteCommitmentTree {
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/// Get the Jubjub-based Pedersen hash of root node of this merkle
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/// tree of commitment notes.
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pub fn hash(&self) -> [u8; 32] {
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unimplemented!();
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}
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}
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impl ZcashSerialize for SaplingNoteCommitmentTree {
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fn zcash_serialize<W: io::Write>(&self, _writer: W) -> Result<(), SerializationError> {
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unimplemented!();
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}
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}
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impl ZcashDeserialize for SaplingNoteCommitmentTree {
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fn zcash_deserialize<R: io::Read>(_reader: R) -> Result<Self, SerializationError> {
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unimplemented!();
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}
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}
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