Move nullifiers to respective note modules, pull in existing types from keys

zebra-chain/src/keys/sprout.rs

@@ -169,6 +169,12 @@ impl From<SpendingKey> for ReceivingKey {
 #[derive(Copy, Clone, Eq, PartialEq)]
 pub struct PayingKey(pub [u8; 32]);
 
+impl AsRef<[u8]> for PayingKey {
+    fn as_ref(&self) -> &[u8] {
+        &self.0
+    }
+}
+
 impl fmt::Debug for PayingKey {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.debug_tuple("PayingKey")

zebra-chain/src/lib.rs

@@ -21,7 +21,6 @@ pub mod equihash_solution;
 pub mod keys;
 pub mod note_commitment_tree;
 pub mod notes;
-pub mod nullifier;
 pub mod parameters;
 pub mod proofs;
 pub mod serialization;

zebra-chain/src/notes/sapling.rs

@@ -1,4 +1,5 @@
 //!
+#![allow(clippy::unit_arg)]
 #![allow(dead_code)]
 
 use std::{fmt, io};
@@ -6,27 +7,46 @@ use std::{fmt, io};
 #[cfg(test)]
 use proptest::{arbitrary::Arbitrary, collection::vec, prelude::*};
 
-use crate::serde_helpers;
-use crate::serialization::{SerializationError, ZcashDeserialize, ZcashSerialize};
-
 use super::*;
+use crate::{
+    keys::sapling::{Diversifier, TransmissionKey},
+    serde_helpers,
+    serialization::{ReadZcashExt, SerializationError, ZcashDeserialize, ZcashSerialize},
+    types::amount::{Amount, NonNegative},
+};
 
-/// A _Diversifier_, an 11 byte value used to randomize the
-/// recipient's final public shielded payment address to create a
-/// _diversified payment address_.
-///
-/// When used, this value is mapped to an affine JubJub group element.
-#[derive(Copy, Clone, Debug, PartialEq)]
-pub struct Diversifier(pub [u8; 11]);
+/// A Nullifier for Sapling transactions
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(test, derive(proptest_derive::Arbitrary))]
+pub struct Nullifier([u8; 32]);
 
-///
+impl From<[u8; 32]> for Nullifier {
+    fn from(buf: [u8; 32]) -> Self {
+        Self(buf)
+    }
+}
+
+impl ZcashDeserialize for Nullifier {
+    fn zcash_deserialize<R: io::Read>(mut reader: R) -> Result<Self, SerializationError> {
+        let bytes = reader.read_32_bytes()?;
+
+        Ok(Self(bytes))
+    }
+}
+
+impl ZcashSerialize for Nullifier {
+    fn zcash_serialize<W: io::Write>(&self, mut writer: W) -> Result<(), io::Error> {
+        writer.write_all(&self.0[..])
+    }
+}
+
+/// A Note represents that a value is spendable by the recipient who
+/// holds the spending key corresponding to a given shielded payment
+/// address.
 pub struct Note {
     diversifier: Diversifier,
-    // TODO: refine as a type, derived from a scalar mult of the
-    // diversifier as a jubjub group element and the incoming view key
-    // scalar.
-    transmission_key: [u8; 32],
-    value: u64,
+    transmission_key: TransmissionKey,
+    value: Amount<NonNegative>,
     note_commitment_randomness: NoteCommitmentRandomness,
 }
 

zebra-chain/src/notes/sprout.rs

@@ -1,29 +1,70 @@
 //!
+#![allow(clippy::unit_arg)]
 #![allow(dead_code)]
 
-use super::{memo::Memo, *};
-use crate::serde_helpers;
-use crate::serialization::{SerializationError, ZcashDeserialize, ZcashSerialize};
-use crate::types::amount::{Amount, NonNegative};
+use std::{fmt, io};
+
 use serde::{Deserialize, Serialize};
 use sha2::{Digest, Sha256};
-use std::{
-    fmt,
-    io::{self},
+
+use crate::{
+    keys::sprout::PayingKey,
+    serde_helpers,
+    serialization::{ReadZcashExt, SerializationError, ZcashDeserialize, ZcashSerialize},
+    types::amount::{Amount, NonNegative},
 };
 
+use super::{memo::Memo, *};
+
+/// Nullifier seed, named rho in the [spec][ps].
 ///
+/// [ps]: https://zips.z.cash/protocol/protocol.pdf#sproutkeycomponents
+#[derive(Clone, Copy)]
+struct NullifierSeed([u8; 32]);
+
+impl AsRef<[u8]> for NullifierSeed {
+    fn as_ref(&self) -> &[u8] {
+        &self.0
+    }
+}
+
+/// A Nullifier Set for Sprout transactions
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(test, derive(proptest_derive::Arbitrary))]
+pub struct Nullifier([u8; 32]);
+
+impl From<[u8; 32]> for Nullifier {
+    fn from(buf: [u8; 32]) -> Self {
+        Self(buf)
+    }
+}
+
+impl ZcashDeserialize for Nullifier {
+    fn zcash_deserialize<R: io::Read>(mut reader: R) -> Result<Self, SerializationError> {
+        let bytes = reader.read_32_bytes()?;
+
+        Ok(Self(bytes))
+    }
+}
+
+impl ZcashSerialize for Nullifier {
+    fn zcash_serialize<W: io::Write>(&self, mut writer: W) -> Result<(), io::Error> {
+        writer.write_all(&self.0[..])
+    }
+}
+
+/// A Note represents that a value is spendable by the recipient who
+/// holds the spending key corresponding to a given shielded payment
+/// address.
 pub struct Note {
-    // TODO: refine type as a SHA-256d output derived from a spending key.
-    paying_key: [u8; 32],
+    paying_key: PayingKey,
     value: Amount<NonNegative>,
-    // TODO: refine type as the input to the PRF that results in a nullifier.
-    nullifier_seed: [u8; 32],
+    nullifier_seed: NullifierSeed,
     note_commitment_randomness: NoteCommitmentRandomness,
 }
 
 impl Note {
-    pub fn note_commitment(&self) -> NoteCommitment {
+    pub fn commitment(&self) -> NoteCommitment {
         let leading_byte: u8 = 0xB0;
         let mut hasher = Sha256::default();
         hasher.input([leading_byte]);
@@ -31,14 +72,13 @@ impl Note {
         hasher.input(self.value.to_bytes());
         hasher.input(self.nullifier_seed);
         hasher.input(self.note_commitment_randomness);
-        let hash = hasher.result().into();
-        NoteCommitment { hash }
+
+        NoteCommitment(hasher.result().into())
     }
 }
 
-pub struct NoteCommitment {
-    hash: [u8; 32],
-}
+///
+pub struct NoteCommitment([u8; 32]);
 
 /// The decrypted form of encrypted Sprout notes on the blockchain.
 pub struct NotePlaintext {

zebra-chain/src/nullifier.rs

@@ -1,4 +0,0 @@
-//! Nullifier set types for sprout and sapling
-
-pub mod sapling;
-pub mod sprout;

zebra-chain/src/nullifier/sapling.rs

@@ -1,30 +0,0 @@
-//! Sapling Nullifier Set types and impls
-#![allow(clippy::unit_arg)]
-use crate::serialization::{ReadZcashExt, SerializationError, ZcashDeserialize, ZcashSerialize};
-use serde::{Deserialize, Serialize};
-use std::io;
-
-/// A Nullifier Set for Sapling transactions
-#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
-#[cfg_attr(test, derive(proptest_derive::Arbitrary))]
-pub struct Nullifier([u8; 32]);
-
-impl From<[u8; 32]> for Nullifier {
-    fn from(buf: [u8; 32]) -> Self {
-        Self(buf)
-    }
-}
-
-impl ZcashDeserialize for Nullifier {
-    fn zcash_deserialize<R: io::Read>(mut reader: R) -> Result<Self, SerializationError> {
-        let bytes = reader.read_32_bytes()?;
-
-        Ok(Self(bytes))
-    }
-}
-
-impl ZcashSerialize for Nullifier {
-    fn zcash_serialize<W: io::Write>(&self, mut writer: W) -> Result<(), io::Error> {
-        writer.write_all(&self.0[..])
-    }
-}

zebra-chain/src/nullifier/sprout.rs

@@ -1,30 +0,0 @@
-//! Sprout Nullifier Set types and impls
-#![allow(clippy::unit_arg)]
-use crate::serialization::{ReadZcashExt, SerializationError, ZcashDeserialize, ZcashSerialize};
-use serde::{Deserialize, Serialize};
-use std::io;
-
-/// A Nullifier Set for Sprout transactions
-#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
-#[cfg_attr(test, derive(proptest_derive::Arbitrary))]
-pub struct Nullifier([u8; 32]);
-
-impl From<[u8; 32]> for Nullifier {
-    fn from(buf: [u8; 32]) -> Self {
-        Self(buf)
-    }
-}
-
-impl ZcashDeserialize for Nullifier {
-    fn zcash_deserialize<R: io::Read>(mut reader: R) -> Result<Self, SerializationError> {
-        let bytes = reader.read_32_bytes()?;
-
-        Ok(Self(bytes))
-    }
-}
-
-impl ZcashSerialize for Nullifier {
-    fn zcash_serialize<W: io::Write>(&self, mut writer: W) -> Result<(), io::Error> {
-        writer.write_all(&self.0[..])
-    }
-}

zebra-chain/src/transaction/joinsplit.rs

@@ -23,7 +23,7 @@ pub struct JoinSplit<P: ZkSnarkProof> {
     /// A nullifier for the input notes.
     ///
     /// XXX refine type to [T; 2] -- there are two nullifiers
-    pub nullifiers: [crate::nullifier::sprout::Nullifier; 2],
+    pub nullifiers: [crate::notes::sprout::Nullifier; 2],
     /// A note commitment for this output note.
     ///
     /// XXX refine type to [T; 2] -- there are two commitments

zebra-chain/src/transaction/serialize.rs

@@ -262,8 +262,8 @@ impl<P: ZkSnarkProof> ZcashDeserialize for JoinSplit<P> {
             vpub_new: reader.read_u64::<LittleEndian>()?.try_into()?,
             anchor: reader.read_32_bytes()?,
             nullifiers: [
-                crate::nullifier::sprout::Nullifier::zcash_deserialize(&mut reader)?,
-                crate::nullifier::sprout::Nullifier::zcash_deserialize(&mut reader)?,
+                crate::notes::sprout::Nullifier::zcash_deserialize(&mut reader)?,
+                crate::notes::sprout::Nullifier::zcash_deserialize(&mut reader)?,
             ],
             commitments: [reader.read_32_bytes()?, reader.read_32_bytes()?],
             ephemeral_key: x25519_dalek::PublicKey::from(reader.read_32_bytes()?),
@@ -335,7 +335,7 @@ impl ZcashDeserialize for Spend {
         Ok(Spend {
             cv: reader.read_32_bytes()?,
             anchor: SaplingNoteTreeRootHash(reader.read_32_bytes()?),
-            nullifier: crate::nullifier::sapling::Nullifier::zcash_deserialize(&mut reader)?,
+            nullifier: crate::notes::sapling::Nullifier::zcash_deserialize(&mut reader)?,
             rk: reader.read_32_bytes()?.into(),
             zkproof: Groth16Proof::zcash_deserialize(&mut reader)?,
             spend_auth_sig: reader.read_64_bytes()?.into(),

zebra-chain/src/transaction/shielded_data.rs

@@ -18,7 +18,7 @@ pub struct Spend {
     /// A root of the Sapling note commitment tree at some block height in the past.
     pub anchor: SaplingNoteTreeRootHash,
     /// The nullifier of the input note.
-    pub nullifier: crate::nullifier::sapling::Nullifier,
+    pub nullifier: crate::notes::sapling::Nullifier,
     /// The randomized public key for `spend_auth_sig`.
     pub rk: redjubjub::VerificationKeyBytes<SpendAuth>,
     /// The ZK spend proof.

zebra-chain/src/transaction/tests/arbitrary.rs

@@ -22,7 +22,7 @@ impl<P: ZkSnarkProof + Arbitrary + 'static> Arbitrary for JoinSplit<P> {
             any::<Amount<NonNegative>>(),
             any::<Amount<NonNegative>>(),
             array::uniform32(any::<u8>()),
-            array::uniform2(any::<crate::nullifier::sprout::Nullifier>()),
+            array::uniform2(any::<crate::notes::sprout::Nullifier>()),
             array::uniform2(array::uniform32(any::<u8>())),
             array::uniform32(any::<u8>()),
             array::uniform32(any::<u8>()),
@@ -155,7 +155,7 @@ impl Arbitrary for Spend {
         (
             array::uniform32(any::<u8>()),
             any::<SaplingNoteTreeRootHash>(),
-            any::<crate::nullifier::sapling::Nullifier>(),
+            any::<crate::notes::sapling::Nullifier>(),
             array::uniform32(any::<u8>()),
             any::<Groth16Proof>(),
             vec(any::<u8>(), 64),