chore: removing leaf data type + related cleanup (AztecProtocol#3794)

1. Removed redundant LeafData struct and used the one from protocol
circuits. I had to move the type to protocol-circuit/rollup-lib to
protocol-circuit/types to have it exposed.
2. Fixes AztecProtocol#3444
3. Unified the naming in NullifierLeafPreimage in TS and Noir.

Author: benesjan

yarn-project/aztec-nr/aztec/src/history/nullifier_inclusion.nr

@@ -17,17 +17,16 @@ pub fn prove_nullifier_inclusion(
     let witness = get_nullifier_membership_witness(block_number, nullifier);
 
     // 3) Check that the witness we obtained matches the nullifier
-    assert(witness.leaf_data.value == nullifier, "Nullifier does not match value in witness");
+    assert(witness.leaf_preimage.nullifier == nullifier, "Nullifier does not match value in witness");
 
     // 4) Compute the nullifier tree leaf
-    let nullifier_leaf = witness.leaf_data.hash();
+    let nullifier_leaf = witness.leaf_preimage.hash();
 
     // 5) Prove that the nullifier is in the nullifier tree
     assert(
-        block_header.nullifier_tree_root == compute_merkle_root(nullifier_leaf, witness.index, witness.path),
-        "Proving nullifier inclusion failed"
+        block_header.nullifier_tree_root
+        == compute_merkle_root(nullifier_leaf, witness.index, witness.path), "Proving nullifier inclusion failed"
     );
-
     // --> Now we have traversed the trees all the way up to archive root and verified that the nullifier
     //     was not yet included in the nullifier tree.
-}
+}

yarn-project/aztec-nr/aztec/src/history/nullifier_non_inclusion.nr

@@ -28,25 +28,23 @@ pub fn prove_nullifier_non_inclusion(
     // 3) Prove that the nullifier is not included in the nullifier tree
 
     // 3.a) Compute the low nullifier leaf and prove that it is in the nullifier tree
-    let low_nullifier_leaf = witness.leaf_data.hash();
+    let low_nullifier_leaf = witness.leaf_preimage.hash();
     assert(
-        block_header.nullifier_tree_root == compute_merkle_root(low_nullifier_leaf, witness.index, witness.path),
-        "Proving nullifier non-inclusion failed: Could not prove low nullifier inclusion"
+        block_header.nullifier_tree_root
+        == compute_merkle_root(low_nullifier_leaf, witness.index, witness.path), "Proving nullifier non-inclusion failed: Could not prove low nullifier inclusion"
     );
 
     // 3.b) Prove that the low nullifier is smaller than the nullifier
     assert(
-        full_field_less_than(witness.leaf_data.value, nullifier),
-        "Proving nullifier non-inclusion failed: low_nullifier.value < nullifier.value check failed"
+        full_field_less_than(witness.leaf_preimage.nullifier, nullifier), "Proving nullifier non-inclusion failed: low_nullifier.value < nullifier.value check failed"
     );
 
     // 3.c) Prove that the low nullifier is pointing "over" the nullifier to prove that the nullifier is not
     // included in the nullifier tree (or to 0 if the to-be-inserted nullifier is the largest of all)
     assert(
-        full_field_greater_than(witness.leaf_data.next_value, nullifier) | (witness.leaf_data.next_index == 0),
-        "Proving nullifier non-inclusion failed: low_nullifier.next_value > nullifier.value check failed"
+        full_field_greater_than(witness.leaf_preimage.next_nullifier, nullifier)
+        | (witness.leaf_preimage.next_index == 0), "Proving nullifier non-inclusion failed: low_nullifier.next_value > nullifier.value check failed"
     );
-
     // --> Now we have traversed the trees all the way up to archive root and verified that the nullifier
     //     was not yet included in the nullifier tree.
 }
@@ -60,4 +58,4 @@ pub fn prove_note_not_nullified<Note, N>(
     let nullifier = compute_siloed_nullifier(note_interface, note_with_header);
 
     prove_nullifier_non_inclusion(nullifier, block_number, context);
-}
+}

yarn-project/aztec-nr/aztec/src/oracle/get_nullifier_membership_witness.nr

@@ -1,50 +1,44 @@
 use dep::protocol_types::{
+    abis::nullifier_leaf_preimage::{
+        NullifierLeafPreimage,
+        NULLIFIER_LEAF_PREIMAGE_LENGTH,
+    },
     constants::NULLIFIER_TREE_HEIGHT,
     hash::pedersen_hash,
 };
 use crate::utils::arr_copy_slice;
 
-global LEAF_DATA_LENGTH: Field = 3;
-// TODO: move this to constants.hpp so that it gets computed as INDEX_LENGTH + LEAF_DATA_LENGTH + NULLIFIER_TREE_HEIGHT
+// INDEX_LENGTH + NULLIFIER_LEAF_PREIMAGE_LENGTH + NULLIFIER_TREE_HEIGHT
 global NULLIFIER_MEMBERSHIP_WITNESS: Field = 24;
 
-// Noir version of LeafData interface from indexed merkle tree.
-// TODO(#3470) replace with /mnt/user-data/jan/aztec-packages/yarn-project/noir-protocol-circuits/src/crates/rollup-lib/src/abis/nullifier_leaf_preimage.nr
-struct LeafData {
-    value: Field,
-    next_index: Field,
-    next_value: Field,
-}
-
-impl LeafData {
-    fn serialize(self) -> [Field; LEAF_DATA_LENGTH] {
-        [self.value, self.next_index, self.next_value]
-    }
-
-    fn hash(self) -> Field {
-        // Performs the same hashing as StandardIndexedTree::encodeLeaf(...)
-        pedersen_hash(self.serialize(), 0)
-    }
-}
-
 struct NullifierMembershipWitness {
     index: Field,
-    leaf_data: LeafData,
+    leaf_preimage: NullifierLeafPreimage,
     path: [Field; NULLIFIER_TREE_HEIGHT],
 }
 
+impl NullifierMembershipWitness {
+    pub fn deserialize(fields: [Field; NULLIFIER_MEMBERSHIP_WITNESS]) -> Self {
+        let leaf_preimage_fields = arr_copy_slice(fields, [0; NULLIFIER_LEAF_PREIMAGE_LENGTH], 1);
+        Self {
+            index: fields[0],
+            leaf_preimage: NullifierLeafPreimage::deserialize(leaf_preimage_fields),
+            path: arr_copy_slice(fields, [0; NULLIFIER_TREE_HEIGHT], 1 + NULLIFIER_LEAF_PREIMAGE_LENGTH)
+        }
+    }
+}
+
 #[oracle(getLowNullifierMembershipWitness)]
-fn get_low_nullifier_membership_witness_oracle(_block_number: u32, _nullifier: Field) -> [Field; NULLIFIER_MEMBERSHIP_WITNESS] {}
+fn get_low_nullifier_membership_witness_oracle(
+    _block_number: u32,
+    _nullifier: Field
+) -> [Field; NULLIFIER_MEMBERSHIP_WITNESS] {}
 
 // Nullifier here refers to the nullifier we are looking to get non-inclusion proof for (by proving that a lower
 // nullifier's next_value is bigger than the nullifier)
 unconstrained pub fn get_low_nullifier_membership_witness(block_number: u32, nullifier: Field) -> NullifierMembershipWitness {
     let fields = get_low_nullifier_membership_witness_oracle(block_number, nullifier);
-    NullifierMembershipWitness {
-        index: fields[0],
-        leaf_data: LeafData { value: fields[1], next_index: fields[2], next_value: fields[3] },
-        path: arr_copy_slice(fields, [0; NULLIFIER_TREE_HEIGHT], 1 + LEAF_DATA_LENGTH)
-    }
+    NullifierMembershipWitness::deserialize(fields)
 }
 
 #[oracle(getNullifierMembershipWitness)]
@@ -54,9 +48,5 @@ fn get_nullifier_membership_witness_oracle(_block_number: u32, _nullifier: Field
 // nullifier's next_value is bigger than the nullifier)
 unconstrained pub fn get_nullifier_membership_witness(block_number: u32, nullifier: Field) -> NullifierMembershipWitness {
     let fields = get_nullifier_membership_witness_oracle(block_number, nullifier);
-    NullifierMembershipWitness {
-        index: fields[0],
-        leaf_data: LeafData { value: fields[1], next_index: fields[2], next_value: fields[3] },
-        path: arr_copy_slice(fields, [0; NULLIFIER_TREE_HEIGHT], 1 + LEAF_DATA_LENGTH)
-    }
-}
+    NullifierMembershipWitness::deserialize(fields)
+}

yarn-project/circuits.js/src/structs/rollup/nullifier_leaf/index.ts

@@ -45,11 +45,15 @@ export class NullifierLeafPreimage implements IndexedTreeLeafPreimage {
   toHashInputs(): Buffer[] {
     return [
       Buffer.from(this.nullifier.toBuffer()),
-      Buffer.from(toBufferBE(this.nextIndex, 32)),
       Buffer.from(this.nextNullifier.toBuffer()),
+      Buffer.from(toBufferBE(this.nextIndex, 32)),
     ];
   }
 
+  toFieldArray(): Fr[] {
+    return this.toHashInputs().map(buf => Fr.fromBuffer(buf));
+  }
+
   clone(): NullifierLeafPreimage {
     return new NullifierLeafPreimage(this.nullifier, this.nextNullifier, this.nextIndex);
   }
@@ -60,8 +64,8 @@ export class NullifierLeafPreimage implements IndexedTreeLeafPreimage {
 
   static fromBuffer(buf: Buffer): NullifierLeafPreimage {
     const nullifier = Fr.fromBuffer(buf.subarray(0, 32));
-    const nextIndex = toBigIntBE(buf.subarray(32, 64));
-    const nextNullifier = Fr.fromBuffer(buf.subarray(64, 96));
+    const nextNullifier = Fr.fromBuffer(buf.subarray(32, 64));
+    const nextIndex = toBigIntBE(buf.subarray(64, 96));
     return new NullifierLeafPreimage(nullifier, nextNullifier, nextIndex);
   }
 

yarn-project/noir-protocol-circuits/src/crates/rollup-lib/src/abis.nr

@@ -1,4 +1,3 @@
-mod nullifier_leaf_preimage;
 mod public_data_tree_leaf;
 mod append_only_tree_snapshot;
 mod global_variables;