From df389b5f593a202bc644479a6c3dff884b7d3652 Mon Sep 17 00:00:00 2001
From: kevaundray <kevtheappdev@gmail.com>
Date: Wed, 25 Oct 2023 20:18:01 +0100
Subject: [PATCH] chore: proxy redundant `hash` methods (#3046)

Partly extracted from #3038

# Checklist:
Remove the checklist to signal you've completed it. Enable auto-merge if
the PR is ready to merge.
- [ ] If the pull request requires a cryptography review (e.g.
cryptographic algorithm implementations) I have added the 'crypto' tag.
- [ ] I have reviewed my diff in github, line by line and removed
unexpected formatting changes, testing logs, or commented-out code.
- [ ] Every change is related to the PR description.
- [ ] I have
[linked](https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue)
this pull request to relevant issues (if any exist).
---
 .../barretenberg/crypto/pedersen/pedersen.ts  | 42 ++-----------------
 yarn-project/merkle-tree/src/pedersen.ts      | 15 +------
 yarn-project/types/src/interfaces/hasher.ts   |  7 ----
 3 files changed, 4 insertions(+), 60 deletions(-)

diff --git a/yarn-project/circuits.js/src/barretenberg/crypto/pedersen/pedersen.ts b/yarn-project/circuits.js/src/barretenberg/crypto/pedersen/pedersen.ts
index 69362c4f878..786976580f5 100644
--- a/yarn-project/circuits.js/src/barretenberg/crypto/pedersen/pedersen.ts
+++ b/yarn-project/circuits.js/src/barretenberg/crypto/pedersen/pedersen.ts
@@ -14,15 +14,7 @@ import { deserializeArrayFromVector, deserializeField, serializeBufferArrayToVec
  * purposes.
  */
 export function pedersenCompress(wasm: IWasmModule, lhs: Uint8Array, rhs: Uint8Array): Buffer {
-  // If not done already, precompute constants.
-  wasm.call('pedersen__init');
-  if (lhs.length !== 32 || rhs.length !== 32) {
-    throw new Error(`Pedersen lhs and rhs inputs must be 32 bytes (got ${lhs.length} and ${rhs.length} respectively)`);
-  }
-  wasm.writeMemory(0, lhs);
-  wasm.writeMemory(32, rhs);
-  wasm.call('pedersen__hash_pair', 0, 32, 64);
-  return Buffer.from(wasm.getMemorySlice(64, 96));
+  return pedersenCompressWithHashIndex(wasm, [Buffer.from(lhs), Buffer.from(rhs)], 0);
 }
 
 /**
@@ -35,12 +27,7 @@ export function pedersenCompress(wasm: IWasmModule, lhs: Uint8Array, rhs: Uint8A
  * purposes.
  */
 export function pedersenHashInputs(wasm: IWasmModule, inputs: Buffer[]): Buffer {
-  // If not done already, precompute constants.
-  wasm.call('pedersen__init');
-  const inputVectors = serializeBufferArrayToVector(inputs);
-  wasm.writeMemory(0, inputVectors);
-  wasm.call('pedersen__hash_multiple', 0, 0);
-  return Buffer.from(wasm.getMemorySlice(0, 32));
+  return pedersenCompressWithHashIndex(wasm, inputs, 0);
 }
 
 /**
@@ -52,12 +39,7 @@ export function pedersenHashInputs(wasm: IWasmModule, inputs: Buffer[]): Buffer
  * purposes.
  */
 export function pedersenCompressInputs(wasm: IWasmModule, inputs: Buffer[]): Buffer {
-  // If not done already, precompute constants.
-  wasm.call('pedersen__init');
-  const inputVectors = serializeBufferArrayToVector(inputs);
-  wasm.writeMemory(0, inputVectors);
-  wasm.call('pedersen__compress', 0, 0);
-  return Buffer.from(wasm.getMemorySlice(0, 32));
+  return pedersenCompressWithHashIndex(wasm, inputs, 0);
 }
 
 /**
@@ -78,24 +60,6 @@ export function pedersenCompressWithHashIndex(wasm: IWasmModule, inputs: Buffer[
   return Buffer.from(wasm.getMemorySlice(0, 32));
 }
 
-/**
- * Get a 32-byte pedersen hash from a buffer.
- * @param wasm - The barretenberg module.
- * @param data - The data buffer.
- * @returns The hash buffer.
- * @deprecated Don't call pedersen directly in production code. Instead, create suitably-named functions for specific
- * purposes.
- */
-export function pedersenGetHash(wasm: IWasmModule, data: Buffer): Buffer {
-  // If not done already, precompute constants.
-  wasm.call('pedersen__init');
-  const mem = wasm.call('bbmalloc', data.length);
-  wasm.writeMemory(mem, data);
-  wasm.call('pedersen__buffer_to_field', mem, data.length, 0);
-  wasm.call('bbfree', mem);
-  return Buffer.from(wasm.getMemorySlice(0, 32));
-}
-
 /**
  * Given a buffer containing 32 byte pedersen leaves, return a new buffer containing the leaves and all pairs of nodes
  * that define a merkle tree.
diff --git a/yarn-project/merkle-tree/src/pedersen.ts b/yarn-project/merkle-tree/src/pedersen.ts
index 7c2c1caecd2..a4c0b57bb9a 100644
--- a/yarn-project/merkle-tree/src/pedersen.ts
+++ b/yarn-project/merkle-tree/src/pedersen.ts
@@ -1,9 +1,4 @@
-import {
-  pedersenCompress,
-  pedersenGetHash,
-  pedersenGetHashTree,
-  pedersenHashInputs,
-} from '@aztec/circuits.js/barretenberg';
+import { pedersenCompress, pedersenGetHashTree, pedersenHashInputs } from '@aztec/circuits.js/barretenberg';
 import { IWasmModule } from '@aztec/foundation/wasm';
 import { Hasher } from '@aztec/types';
 
@@ -31,14 +26,6 @@ export class Pedersen implements Hasher {
     return pedersenHashInputs(this.wasm, inputs);
   }
 
-  /*
-   * @deprecated Don't call pedersen directly in production code. Instead, create suitably-named functions for specific
-   * purposes.
-   */
-  public hashToField(data: Uint8Array): Buffer {
-    return pedersenGetHash(this.wasm, Buffer.from(data));
-  }
-
   /*
    * @deprecated Don't call pedersen directly in production code. Instead, create suitably-named functions for specific
    * purposes.
diff --git a/yarn-project/types/src/interfaces/hasher.ts b/yarn-project/types/src/interfaces/hasher.ts
index aea50dc0ae1..e5e7178972d 100644
--- a/yarn-project/types/src/interfaces/hasher.ts
+++ b/yarn-project/types/src/interfaces/hasher.ts
@@ -17,13 +17,6 @@ export interface Hasher {
    */
   compressInputs(inputs: Buffer[]): Buffer;
 
-  /**
-   * Get a 32-byte hash from a buffer.
-   * @param data - The data buffer.
-   * @returns The resulting hash buffer.
-   */
-  hashToField(data: Uint8Array): Buffer;
-
   /**
    * Given a buffer containing 32 byte leaves, return a new buffer containing the leaves and all pairs of
    * nodes that define a merkle tree.