feat: allow using of current block in inclusion proofs (#4285)

Fixes #4274

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

@@ -18,32 +18,40 @@ unconstrained pub fn get_header_at_internal(block_number: u32) -> Header {
 }
 
 pub fn get_header_at(block_number: u32, context: PrivateContext) -> Header {
-    // 1) Get block number corresponding to the last_archive root in the header
-    // Note: We subtract 1 because the last_archive root is the root of the archive after applying the previous block
-    let last_archive_block_number = (context.historical_header.global_variables.block_number - 1) as u32;
-
-    // 2) Check that the last archive block number is more than or equal to the block number we want to prove against
-    // We could not perform the proof otherwise because the last archive root from the header would not "contain"
-    // the header we want to prove against
-    assert(
-        last_archive_block_number >= block_number, "Last archive block number is smaller than the block number we want to prove against"
-    );
-
-    // 3) Get the header of a given block from oracle
-    let header = get_header_at_internal(block_number);
-
-    // 4) Compute the block hash from the block header
-    let block_hash = header.block_hash();
-
-    // 5) Get the membership witness of the block in the archive
-    let witness = get_archive_membership_witness(last_archive_block_number, block_hash);
-
-    // 6) Check that the block is in the archive (i.e. the witness is valid)
-    assert(
-        context.historical_header.last_archive.root
-        == compute_merkle_root(block_hash, witness.index, witness.path), "Proving membership of a block in archive failed"
-    );
-
-    // 7) Return the block header
-    header
+    let historical_header_block_number = context.historical_header.global_variables.block_number as u32;
+
+    if (block_number == historical_header_block_number) {
+        // If the block number we want to prove against is the same as the block number in the historical header we
+        // skip the inclusion proofs and just return the historical header from context.
+        context.historical_header
+    } else {
+        // 1) Get block number corresponding to the last_archive root in the header
+        // Note: We subtract 1 because the last_archive root is the root of the archive after applying the previous block
+        let last_archive_block_number = historical_header_block_number - 1;
+
+        // 2) Check that the last archive block number is more than or equal to the block number we want to prove against
+        // We could not perform the proof otherwise because the last archive root from the header would not "contain"
+        // the header we want to prove against
+        assert(
+            last_archive_block_number >= block_number, "Last archive block number is smaller than the block number we want to prove against"
+        );
+
+        // 3) Get the header of a given block from oracle
+        let header = get_header_at_internal(block_number);
+
+        // 4) Compute the block hash from the block header
+        let block_hash = header.block_hash();
+
+        // 5) Get the membership witness of the block in the archive
+        let witness = get_archive_membership_witness(last_archive_block_number, block_hash);
+
+        // 6) Check that the block is in the archive (i.e. the witness is valid)
+        assert(
+            context.historical_header.last_archive.root
+            == compute_merkle_root(block_hash, witness.index, witness.path), "Proving membership of a block in archive failed"
+        );
+
+        // 7) Return the block header
+        header
+    }
 }

yarn-project/end-to-end/src/e2e_inclusion_proofs_contract.test.ts

@@ -70,11 +70,6 @@ describe('e2e_inclusion_proofs_contract', () => {
         expect(receivedOwner).toEqual(owner.toField());
       }
 
-      // We advance block to be able to prove against block with `noteCreationBlockNumber` --> we have to do this
-      // because `last_archive` root in the `Header` of aztec-nr contexts is the root of the archive after applying
-      // the previous block and not the current one.
-      await advanceBlock();
-
       {
         // Prove note inclusion in a given block.
         const ignoredCommitment = 0; // Not ignored only when the note doesn't exist
@@ -88,7 +83,7 @@ describe('e2e_inclusion_proofs_contract', () => {
         // Prove that the note has not been nullified
         // TODO(#3535): Prove the nullifier non-inclusion at older block to test archival node. This is currently not
         // possible because of issue https://github.com/AztecProtocol/aztec-packages/issues/3535
-        const blockNumber = await getLatestUsableBlockNumber();
+        const blockNumber = await pxe.getBlockNumber();
         const ignoredNullifier = 0; // Not ignored only when the note doesn't exist
         await contract.methods.test_nullifier_non_inclusion_proof(owner, blockNumber, ignoredNullifier).send().wait();
       }
@@ -99,10 +94,7 @@ describe('e2e_inclusion_proofs_contract', () => {
         const { newNullifiers } = receipt.debugInfo!;
         expect(newNullifiers.length).toBe(2);
 
-        // Once again we advance the block to be able to access the correct archive root,
-        await advanceBlock();
-
-        const blockNumber = await getLatestUsableBlockNumber();
+        const blockNumber = await pxe.getBlockNumber();
         const nullifier = newNullifiers[1];
         // Note: getLowNullifierMembershipWitness returns the membership witness of the nullifier itself and not
         // the low nullifier when the nullifier already exists in the tree and for this reason the execution fails
@@ -134,11 +126,6 @@ describe('e2e_inclusion_proofs_contract', () => {
         expect(receivedOwner).toEqual(owner.toField());
       }
 
-      // We advance block to be able to prove against block with `noteCreationBlockNumber` --> we have to do this
-      // because `last_archive` root in the `Header` of aztec-nr contexts is the root of the archive after applying
-      // the previous block and not the current one.
-      await advanceBlock();
-
       {
         // Prove note validity
         await contract.methods.test_note_validity_proof(owner, noteCreationBlockNumber).send().wait();
@@ -264,26 +251,10 @@ describe('e2e_inclusion_proofs_contract', () => {
   });
 
   const getRandomBlockNumberSinceDeployment = async () => {
-    return (
-      deploymentBlockNumber + Math.floor(Math.random() * ((await getLatestUsableBlockNumber()) - deploymentBlockNumber))
-    );
+    return deploymentBlockNumber + Math.floor(Math.random() * ((await pxe.getBlockNumber()) - deploymentBlockNumber));
   };
 
   const getRandomBlockNumber = async () => {
-    return (
-      deploymentBlockNumber + Math.floor(Math.random() * ((await getLatestUsableBlockNumber()) - INITIAL_L2_BLOCK_NUM))
-    );
-  };
-
-  const getLatestUsableBlockNumber = async () => {
-    const currentBlockNumber = await pxe.getBlockNumber();
-    // Note: We subtract 1 from current because the `last_archive` root in the `Header` of aztec-nr contexts is
-    // the root of the archive after applying the previous block and not the current one.
-    return currentBlockNumber - 1;
-  };
-
-  // We advance block by sending a transaction calling empty function on our contract.
-  const advanceBlock = async () => {
-    await contract.methods.empty().send().wait();
+    return deploymentBlockNumber + Math.floor(Math.random() * ((await pxe.getBlockNumber()) - INITIAL_L2_BLOCK_NUM));
   };
 });

yarn-project/noir-contracts/contracts/inclusion_proofs_contract/src/main.nr

@@ -234,9 +234,6 @@ contract InclusionProofs {
         // Here typically the factory would add the contract address to its internal map of deployed contracts.
     }
 
-    #[aztec(private)]
-    fn empty() {}
-
     // Computes note hash and nullifier.
     // Note 1: Needs to be defined by every contract producing logs.
     // Note 2: Having it in all the contracts gives us the ability to compute the note hash and nullifier differently for different kind of notes.