refactor: leveraging Bufferable in pedersenHash(...) and `sha256T…

…oField(...)` (#5444)

We had a ton of manual conversions to buffer when computing hashes. A
few PRs ago I sneaked in a modification and pedersenHash(...) now
accepts `Bufferable[]` instead of `Buffer[]`. In this PR I leverage this
and remove the unnecessary conversions and do the same for
`sha256ToField(...)`.

yarn-project/aztec.js/src/utils/authwit.ts

@@ -40,10 +40,7 @@ export const computeAuthWitMessageHash = (caller: AztecAddress, chainId: Fr, ver
  * @returns The inner hash for the witness
  */
 export const computeInnerAuthWitHash = (args: Fr[]) => {
-  return pedersenHash(
-    args.map(fr => fr.toBuffer()),
-    GeneratorIndex.AUTHWIT_INNER,
-  );
+  return pedersenHash(args, GeneratorIndex.AUTHWIT_INNER);
 };
 
 /**
@@ -61,8 +58,5 @@ export const computeInnerAuthWitHash = (args: Fr[]) => {
  * @returns The outer hash for the witness
  */
 export const computeOuterAuthWitHash = (consumer: AztecAddress, chainId: Fr, version: Fr, innerHash: Fr) => {
-  return pedersenHash(
-    [consumer.toField(), chainId, version, innerHash].map(fr => fr.toBuffer()),
-    GeneratorIndex.AUTHWIT_OUTER,
-  );
+  return pedersenHash([consumer.toField(), chainId, version, innerHash], GeneratorIndex.AUTHWIT_OUTER);
 };

yarn-project/aztec.js/src/utils/cheat_codes.ts

@@ -246,7 +246,7 @@ export class AztecCheatCodes {
   public computeSlotInMap(baseSlot: Fr | bigint, key: Fr | bigint | AztecAddress): Fr {
     // Based on `at` function in
     // aztec3-packages/aztec-nr/aztec/src/state_vars/map.nr
-    return pedersenHash([new Fr(baseSlot), new Fr(key)].map(f => f.toBuffer()));
+    return pedersenHash([new Fr(baseSlot), new Fr(key)]);
   }
 
   /**

yarn-project/circuit-types/src/l2_block.ts

@@ -145,7 +145,7 @@ export class L2Block {
    */
   // TODO(#4844)
   getPublicInputsHash(): Fr {
-    const buf = serializeToBuffer(
+    const preimage = [
       this.header.globalVariables,
       AppendOnlyTreeSnapshot.zero(), // this.startNoteHashTreeSnapshot / commitments,
       AppendOnlyTreeSnapshot.zero(), // this.startNullifierTreeSnapshot,
@@ -158,9 +158,9 @@ export class L2Block {
       this.header.state.l1ToL2MessageTree,
       this.archive,
       this.body.getTxsEffectsHash(),
-    );
+    ];
 
-    return sha256ToField(buf);
+    return sha256ToField(preimage);
   }
 
   /**

yarn-project/circuit-types/src/messaging/l1_to_l2_message.ts

@@ -41,7 +41,7 @@ export class L1ToL2Message {
   }
 
   hash(): Fr {
-    return sha256ToField(serializeToBuffer(...this.toFields()));
+    return sha256ToField(this.toFields());
   }
 
   static fromBuffer(buffer: Buffer | BufferReader): L1ToL2Message {

yarn-project/circuits.js/src/contract/contract_address.ts

@@ -43,10 +43,7 @@ export function computePartialAddress(
       ? instance.saltedInitializationHash
       : computeSaltedInitializationHash(instance);
 
-  return pedersenHash(
-    [instance.contractClassId, saltedInitializationHash].map(x => x.toBuffer()),
-    GeneratorIndex.PARTIAL_ADDRESS,
-  );
+  return pedersenHash([instance.contractClassId, saltedInitializationHash], GeneratorIndex.PARTIAL_ADDRESS);
 }
 
 /**
@@ -57,9 +54,7 @@ export function computeSaltedInitializationHash(
   instance: Pick<ContractInstance, 'initializationHash' | 'salt' | 'portalContractAddress' | 'deployer'>,
 ): Fr {
   return pedersenHash(
-    [instance.salt, instance.initializationHash, instance.deployer, instance.portalContractAddress].map(x =>
-      x.toBuffer(),
-    ),
+    [instance.salt, instance.initializationHash, instance.deployer, instance.portalContractAddress],
     GeneratorIndex.PARTIAL_ADDRESS,
   );
 }
@@ -73,10 +68,7 @@ export function computeContractAddressFromPartial(
   args: ({ publicKeyHash: Fr } | { publicKey: PublicKey }) & { partialAddress: Fr },
 ): AztecAddress {
   const publicKeyHash = 'publicKey' in args ? computePublicKeysHash(args.publicKey) : args.publicKeyHash;
-  const result = pedersenHash(
-    [publicKeyHash.toBuffer(), args.partialAddress.toBuffer()],
-    GeneratorIndex.CONTRACT_ADDRESS,
-  );
+  const result = pedersenHash([publicKeyHash, args.partialAddress], GeneratorIndex.CONTRACT_ADDRESS);
   return AztecAddress.fromField(result);
 }
 
@@ -89,7 +81,7 @@ export function computePublicKeysHash(publicKey: PublicKey | undefined): Fr {
   if (!publicKey) {
     return Fr.ZERO;
   }
-  return pedersenHash([publicKey.x.toBuffer(), publicKey.y.toBuffer()], GeneratorIndex.PARTIAL_ADDRESS);
+  return pedersenHash([publicKey.x, publicKey.y], GeneratorIndex.PARTIAL_ADDRESS);
 }
 
 /**
@@ -115,5 +107,5 @@ export function computeInitializationHash(initFn: FunctionAbi | undefined, args:
  */
 export function computeInitializationHashFromEncodedArgs(initFn: FunctionSelector, encodedArgs: Fr[]): Fr {
   const argsHash = computeVarArgsHash(encodedArgs);
-  return pedersenHash([initFn.toBuffer(), argsHash.toBuffer()], GeneratorIndex.CONSTRUCTOR);
+  return pedersenHash([initFn, argsHash], GeneratorIndex.CONSTRUCTOR);
 }

yarn-project/circuits.js/src/contract/contract_class_id.ts

@@ -36,7 +36,7 @@ export function computeContractClassIdWithPreimage(
       ? contractClass.publicBytecodeCommitment
       : computePublicBytecodeCommitment(contractClass.packedBytecode);
   const id = pedersenHash(
-    [artifactHash.toBuffer(), privateFunctionsRoot.toBuffer(), publicBytecodeCommitment.toBuffer()],
+    [artifactHash, privateFunctionsRoot, publicBytecodeCommitment],
     GeneratorIndex.CONTRACT_LEAF, // TODO(@spalladino): Review all generator indices in this file
   );
   return { id, artifactHash, privateFunctionsRoot, publicBytecodeCommitment };

yarn-project/circuits.js/src/contract/private_function.ts

@@ -27,10 +27,7 @@ function computePrivateFunctionLeaves(fns: PrivateFunction[]): Buffer[] {
 
 /** Returns the leaf for a given private function. */
 export function computePrivateFunctionLeaf(fn: PrivateFunction): Buffer {
-  return pedersenHash(
-    [fn.selector, fn.vkHash].map(x => x.toBuffer()),
-    GeneratorIndex.FUNCTION_LEAF,
-  ).toBuffer();
+  return pedersenHash([fn.selector, fn.vkHash], GeneratorIndex.FUNCTION_LEAF).toBuffer();
 }
 
 function getPrivateFunctionTreeCalculator(): MerkleTreeCalculator {

yarn-project/circuits.js/src/hash/hash.ts

@@ -61,7 +61,7 @@ export function hashVK(vkBuf: Buffer) {
  * @returns A commitment nonce.
  */
 export function computeCommitmentNonce(nullifierZero: Fr, commitmentIndex: number): Fr {
-  return pedersenHash([nullifierZero.toBuffer(), numToUInt32BE(commitmentIndex, 32)], GeneratorIndex.NOTE_HASH_NONCE);
+  return pedersenHash([nullifierZero, numToUInt32BE(commitmentIndex, 32)], GeneratorIndex.NOTE_HASH_NONCE);
 }
 
 /**
@@ -72,7 +72,7 @@ export function computeCommitmentNonce(nullifierZero: Fr, commitmentIndex: numbe
  * @returns A siloed commitment.
  */
 export function siloNoteHash(contract: AztecAddress, innerNoteHash: Fr): Fr {
-  return pedersenHash([contract.toBuffer(), innerNoteHash.toBuffer()], GeneratorIndex.SILOED_NOTE_HASH);
+  return pedersenHash([contract, innerNoteHash], GeneratorIndex.SILOED_NOTE_HASH);
 }
 
 /**
@@ -82,7 +82,7 @@ export function siloNoteHash(contract: AztecAddress, innerNoteHash: Fr): Fr {
  * @returns A unique commitment.
  */
 export function computeUniqueCommitment(nonce: Fr, siloedCommitment: Fr): Fr {
-  return pedersenHash([nonce.toBuffer(), siloedCommitment.toBuffer()], GeneratorIndex.UNIQUE_NOTE_HASH);
+  return pedersenHash([nonce, siloedCommitment], GeneratorIndex.UNIQUE_NOTE_HASH);
 }
 
 /**
@@ -93,7 +93,7 @@ export function computeUniqueCommitment(nonce: Fr, siloedCommitment: Fr): Fr {
  * @returns A siloed nullifier.
  */
 export function siloNullifier(contract: AztecAddress, innerNullifier: Fr): Fr {
-  return pedersenHash([contract.toBuffer(), innerNullifier.toBuffer()], GeneratorIndex.OUTER_NULLIFIER);
+  return pedersenHash([contract, innerNullifier], GeneratorIndex.OUTER_NULLIFIER);
 }
 
 /**
@@ -114,7 +114,7 @@ export function computePublicDataTreeValue(value: Fr): Fr {
 
  */
 export function computePublicDataTreeLeafSlot(contractAddress: AztecAddress, storageSlot: Fr): Fr {
-  return pedersenHash([contractAddress.toBuffer(), storageSlot.toBuffer()], GeneratorIndex.PUBLIC_LEAF_INDEX);
+  return pedersenHash([contractAddress, storageSlot], GeneratorIndex.PUBLIC_LEAF_INDEX);
 }
 
 /**
@@ -138,31 +138,22 @@ export function computeVarArgsHash(args: Fr[]) {
     if (c.length < ARGS_HASH_CHUNK_LENGTH) {
       c = padArrayEnd(c, Fr.ZERO, ARGS_HASH_CHUNK_LENGTH);
     }
-    return pedersenHash(
-      c.map(a => a.toBuffer()),
-      GeneratorIndex.FUNCTION_ARGS,
-    );
+    return pedersenHash(c, GeneratorIndex.FUNCTION_ARGS);
   });
 
   if (chunksHashes.length < ARGS_HASH_CHUNK_COUNT) {
     chunksHashes = padArrayEnd(chunksHashes, Fr.ZERO, ARGS_HASH_CHUNK_COUNT);
   }
 
-  return pedersenHash(
-    chunksHashes.map(a => a.toBuffer()),
-    GeneratorIndex.FUNCTION_ARGS,
-  );
+  return pedersenHash(chunksHashes, GeneratorIndex.FUNCTION_ARGS);
 }
 
 export function computeCommitmentsHash(input: SideEffect) {
-  return pedersenHash([input.value.toBuffer(), input.counter.toBuffer()], GeneratorIndex.SIDE_EFFECT);
+  return pedersenHash([input.value, input.counter], GeneratorIndex.SIDE_EFFECT);
 }
 
 export function computeNullifierHash(input: SideEffectLinkedToNoteHash) {
-  return pedersenHash(
-    [input.value.toBuffer(), input.noteHash.toBuffer(), input.counter.toBuffer()],
-    GeneratorIndex.SIDE_EFFECT,
-  );
+  return pedersenHash([input.value, input.noteHash, input.counter], GeneratorIndex.SIDE_EFFECT);
 }
 
 /**
@@ -171,7 +162,7 @@ export function computeNullifierHash(input: SideEffectLinkedToNoteHash) {
  * @returns the hash
  */
 export function computeMessageSecretHash(secretMessage: Fr) {
-  return pedersenHash([secretMessage.toBuffer()], GeneratorIndex.L1_TO_L2_MESSAGE_SECRET);
+  return pedersenHash([secretMessage], GeneratorIndex.L1_TO_L2_MESSAGE_SECRET);
 }
 
 export function computeL1ToL2MessageNullifier(

yarn-project/circuits.js/src/keys/index.ts

@@ -19,7 +19,7 @@ export function derivePublicKey(secretKey: GrumpkinPrivateKey) {
 function deriveSecretKey(secretKey: GrumpkinPrivateKey, index: Fr): GrumpkinPrivateKey {
   // TODO: Temporary hack. Should replace it with a secure way to derive the secret key.
   // Match the way keys are derived in noir-protocol-circuits/crates/private_kernel_lib/src/common.nr
-  const hash = pedersenHash([secretKey.high, secretKey.low, index].map(v => v.toBuffer()));
+  const hash = pedersenHash([secretKey.high, secretKey.low, index]);
   return new GrumpkinScalar(hash.toBuffer());
 }
 

yarn-project/circuits.js/src/structs/function_data.ts

@@ -87,9 +87,6 @@ export class FunctionData {
   }
 
   hash(): Fr {
-    return pedersenHash(
-      this.toFields().map(field => field.toBuffer()),
-      GeneratorIndex.FUNCTION_DATA,
-    );
+    return pedersenHash(this.toFields(), GeneratorIndex.FUNCTION_DATA);
   }
 }

yarn-project/circuits.js/src/structs/header.ts

@@ -94,9 +94,6 @@ export class Header {
   }
 
   hash(): Fr {
-    return pedersenHash(
-      this.toFields().map(f => f.toBuffer()),
-      GeneratorIndex.BLOCK_HASH,
-    );
+    return pedersenHash(this.toFields(), GeneratorIndex.BLOCK_HASH);
   }
 }

yarn-project/circuits.js/src/structs/private_call_stack_item.ts

@@ -91,10 +91,7 @@ export class PrivateCallStackItem {
    * @returns Hash.
    */
   public hash(): Fr {
-    return pedersenHash(
-      this.toFields().map(field => field.toBuffer()),
-      GeneratorIndex.CALL_STACK_ITEM,
-    );
+    return pedersenHash(this.toFields(), GeneratorIndex.CALL_STACK_ITEM);
   }
 
   /**

yarn-project/circuits.js/src/structs/private_circuit_public_inputs.ts

@@ -317,9 +317,6 @@ export class PrivateCircuitPublicInputs {
   }
 
   hash(): Fr {
-    return pedersenHash(
-      this.toFields().map(field => field.toBuffer()),
-      GeneratorIndex.PRIVATE_CIRCUIT_PUBLIC_INPUTS,
-    );
+    return pedersenHash(this.toFields(), GeneratorIndex.PRIVATE_CIRCUIT_PUBLIC_INPUTS);
   }
 }

yarn-project/circuits.js/src/structs/public_call_stack_item.ts

@@ -97,7 +97,7 @@ export class PublicCallStackItem {
     }
 
     return pedersenHash(
-      [this.contractAddress, this.functionData.hash(), this.publicInputs.hash()].map(f => f.toBuffer()),
+      [this.contractAddress, this.functionData.hash(), this.publicInputs.hash()],
       GeneratorIndex.CALL_STACK_ITEM,
     );
   }

yarn-project/circuits.js/src/structs/public_circuit_public_inputs.ts

@@ -280,9 +280,6 @@ export class PublicCircuitPublicInputs {
   }
 
   hash(): Fr {
-    return pedersenHash(
-      this.toFields().map(field => field.toBuffer()),
-      GeneratorIndex.PUBLIC_CIRCUIT_PUBLIC_INPUTS,
-    );
+    return pedersenHash(this.toFields(), GeneratorIndex.PUBLIC_CIRCUIT_PUBLIC_INPUTS);
   }
 }

yarn-project/circuits.js/src/structs/tx_context.ts

@@ -90,9 +90,6 @@ export class TxContext {
   }
 
   hash(): Fr {
-    return pedersenHash(
-      this.toFields().map(f => f.toBuffer()),
-      GeneratorIndex.TX_CONTEXT,
-    );
+    return pedersenHash(this.toFields(), GeneratorIndex.TX_CONTEXT);
   }
 }

yarn-project/circuits.js/src/structs/tx_request.ts

@@ -71,10 +71,7 @@ export class TxRequest {
   }
 
   hash() {
-    return pedersenHash(
-      this.toFields().map(field => field.toBuffer()),
-      GeneratorIndex.TX_REQUEST,
-    );
+    return pedersenHash(this.toFields(), GeneratorIndex.TX_REQUEST);
   }
 
   static empty() {

yarn-project/end-to-end/src/e2e_block_building.test.ts

@@ -154,7 +154,7 @@ describe('e2e_block_building', () => {
       it('drops tx with private nullifier already emitted from public on the same block', async () => {
         const secret = Fr.random();
         // See yarn-project/simulator/src/public/index.test.ts 'Should be able to create a nullifier from the public context'
-        const emittedPublicNullifier = pedersenHash([new Fr(140), secret].map(a => a.toBuffer()));
+        const emittedPublicNullifier = pedersenHash([new Fr(140), secret]);
 
         const calls = [
           contract.methods.create_nullifier_public(140n, secret),
@@ -172,7 +172,7 @@ describe('e2e_block_building', () => {
     describe('across blocks', () => {
       it('drops a tx that tries to spend a nullifier already emitted on a previous block', async () => {
         const secret = Fr.random();
-        const emittedPublicNullifier = pedersenHash([new Fr(140), secret].map(a => a.toBuffer()));
+        const emittedPublicNullifier = pedersenHash([new Fr(140), secret]);
 
         await expect(contract.methods.create_nullifier_public(140n, secret).send().wait()).resolves.toEqual(
           expect.objectContaining({

yarn-project/end-to-end/src/e2e_cross_chain_messaging.test.ts

@@ -11,7 +11,6 @@ import {
   computeAuthWitMessageHash,
 } from '@aztec/aztec.js';
 import { sha256ToField } from '@aztec/foundation/crypto';
-import { serializeToBuffer } from '@aztec/foundation/serialize';
 import { TokenBridgeContract, TokenContract } from '@aztec/noir-contracts.js';
 
 import { toFunctionSelector } from 'viem/utils';
@@ -157,12 +156,11 @@ describe('e2e_cross_chain_messaging', () => {
     await crossChainTestHarness.makeMessageConsumable(msgHash);
 
     // 3. Consume L1 -> L2 message and mint private tokens on L2
-    const content = sha256ToField(
-      Buffer.concat([
-        Buffer.from(toFunctionSelector('mint_private(bytes32,uint256)').substring(2), 'hex'),
-        serializeToBuffer(...[secretHashForL2MessageConsumption, new Fr(bridgeAmount)]),
-      ]),
-    );
+    const content = sha256ToField([
+      Buffer.from(toFunctionSelector('mint_private(bytes32,uint256)').substring(2), 'hex'),
+      secretHashForL2MessageConsumption,
+      new Fr(bridgeAmount),
+    ]);
     const wrongMessage = new L1ToL2Message(
       new L1Actor(crossChainTestHarness.tokenPortalAddress, crossChainTestHarness.publicClient.chain.id),
       new L2Actor(l2Bridge.address, 1),
@@ -235,12 +233,11 @@ describe('e2e_cross_chain_messaging', () => {
     // Wait for the message to be available for consumption
     await crossChainTestHarness.makeMessageConsumable(msgHash);
 
-    const content = sha256ToField(
-      Buffer.concat([
-        Buffer.from(toFunctionSelector('mint_public(bytes32,uint256)').substring(2), 'hex'),
-        serializeToBuffer(...[ownerAddress, new Fr(bridgeAmount)]),
-      ]),
-    );
+    const content = sha256ToField([
+      Buffer.from(toFunctionSelector('mint_public(bytes32,uint256)').substring(2), 'hex'),
+      ownerAddress,
+      new Fr(bridgeAmount),
+    ]);
     const wrongMessage = new L1ToL2Message(
       new L1Actor(crossChainTestHarness.tokenPortalAddress, crossChainTestHarness.publicClient.chain.id),
       new L2Actor(l2Bridge.address, 1),