chore(circuits): - remove dead code from cbind of private kernel circ…

…uit (#2088)

Resolves #2087 

# Checklist:
Remove the checklist to signal you've completed it. Enable auto-merge if
the PR is ready to merge.
- [x] If the pull request requires a cryptography review (e.g.
cryptographic algorithm implementations) I have added the 'crypto' tag.
- [x] I have reviewed my diff in github, line by line and removed
unexpected formatting changes, testing logs, or commented-out code.
- [x] Every change is related to the PR description.
- [x] I have
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this pull request to relevant issues (if any exist).

circuits/cpp/src/aztec3/circuits/kernel/private/.test.cpp

@@ -1,4 +1,3 @@
-#include "c_bind.h"
 #include "index.hpp"
 #include "init.hpp"
 #include "testing_harness.hpp"
@@ -94,19 +93,6 @@ TEST_F(private_kernel_tests, circuit_cbinds)
    DummyBuilder builder = DummyBuilder("private_kernel_tests__circuit_create_proof_cbinds");
    auto const& public_inputs = native_private_kernel_circuit_initial(builder, private_inputs);
 
-   // ***************************************************************************
-   //  Now run the simulate/prove cbinds to make sure their outputs match
-   // ***************************************************************************
-   // TODO(david): might be able to get rid of proving key buffer
-   uint8_t const* pk_buf = nullptr;
-   private_kernel__init_proving_key(&pk_buf);
-   // info("Proving key size: ", pk_size);
-
-   // TODO(david): might be able to get rid of verification key buffer
-   // uint8_t const* vk_buf;
-   // size_t vk_size = private_kernel__init_verification_key(pk_buf, &vk_buf);
-   // info("Verification key size: ", vk_size);
-
    auto exp_result = builder.result_or_error(public_inputs);
    // Does not compile. See https://github.com/AztecProtocol/aztec-packages/issues/1998
    auto res = call_msgpack_cbind<decltype(exp_result)>(private_kernel__sim_init, private_inputs);

circuits/cpp/src/aztec3/circuits/kernel/private/c_bind.cpp

@@ -16,8 +16,6 @@ namespace {
 using Builder = UltraCircuitBuilder;
 using NT = aztec3::utils::types::NativeTypes;
 using DummyCircuitBuilder = aztec3::utils::DummyCircuitBuilder;
-using aztec3::circuits::abis::TxRequest;
-using aztec3::circuits::abis::private_kernel::PrivateCallData;
 using aztec3::circuits::abis::private_kernel::PrivateKernelInputsInit;
 using aztec3::circuits::abis::private_kernel::PrivateKernelInputsInner;
 using aztec3::circuits::abis::private_kernel::PrivateKernelInputsOrdering;
@@ -30,35 +28,6 @@ using aztec3::circuits::kernel::private_kernel::utils::dummy_previous_kernel;
 
 // WASM Cbinds
 
-// TODO(dbanks12): might be able to get rid of proving key buffer
-WASM_EXPORT size_t private_kernel__init_proving_key(uint8_t const** pk_buf)
-{
-    std::vector<uint8_t> pk_vec(42, 0);
-
-    auto* raw_buf = (uint8_t*)malloc(pk_vec.size());
-    memcpy(raw_buf, (void*)pk_vec.data(), pk_vec.size());
-    *pk_buf = raw_buf;
-
-    return pk_vec.size();
-}
-
-WASM_EXPORT size_t private_kernel__init_verification_key(uint8_t const* pk_buf, uint8_t const** vk_buf)
-{
-    (void)pk_buf;
-
-    // TODO(dbanks12) actual verification key?
-    // NT:VKData vk_data = { 0 };
-
-    std::vector<uint8_t> vk_vec(42, 0);
-    // write(vk_vec, vk_data);
-
-    auto* raw_buf = (uint8_t*)malloc(vk_vec.size());
-    memcpy(raw_buf, (void*)vk_vec.data(), vk_vec.size());
-    *vk_buf = raw_buf;
-
-    return vk_vec.size();
-}
-
 CBIND(private_kernel__dummy_previous_kernel, []() { return dummy_previous_kernel(); });
 
 CBIND(private_kernel__sim_init, [](PrivateKernelInputsInit<NT> private_inputs) {

circuits/cpp/src/aztec3/circuits/kernel/private/c_bind.h

@@ -4,16 +4,7 @@
 #include <cstddef>
 #include <cstdint>
 
-WASM_EXPORT size_t private_kernel__init_proving_key(uint8_t const** pk_buf);
-WASM_EXPORT size_t private_kernel__init_verification_key(uint8_t const* pk_buf, uint8_t const** vk_buf);
 CBIND_DECL(private_kernel__dummy_previous_kernel);
 CBIND_DECL(private_kernel__sim_init);
 CBIND_DECL(private_kernel__sim_inner);
 CBIND_DECL(private_kernel__sim_ordering);
-WASM_EXPORT size_t private_kernel__prove(uint8_t const* tx_request_buf,
-                                         uint8_t const* previous_kernel_buf,
-                                         uint8_t const* private_call_buf,
-                                         uint8_t const* pk_buf,
-                                         bool first,
-                                         uint8_t const** proof_data_buf);
-WASM_EXPORT size_t private_kernel__verify_proof(uint8_t const* vk_buf, uint8_t const* proof, uint32_t length);

yarn-project/circuits.js/src/kernel/private_kernel.ts

@@ -2,8 +2,8 @@ import { BufferReader } from '@aztec/foundation/serialize';
 
 import { Buffer } from 'buffer';
 
-import { FUNCTION_TREE_HEIGHT, Fr, PreviousKernelData, PrivateCallData, TxRequest } from '../index.js';
-import { serializeBufferArrayToVector, uint8ArrayToNum } from '../utils/serialize.js';
+import { FUNCTION_TREE_HEIGHT, Fr } from '../index.js';
+import { serializeBufferArrayToVector } from '../utils/serialize.js';
 import { CircuitsWasm } from '../wasm/index.js';
 
 export { privateKernelSimOrdering, privateKernelSimInit, privateKernelSimInner } from '../cbind/circuits.gen.js';
@@ -40,49 +40,3 @@ export function computeFunctionTree(wasm: CircuitsWasm, leaves: Fr[]): Fr[] {
 
   return output;
 }
-
-/**
- * Computes proof of the private kernel.
- * @param wasm - The circuits wasm instance.
- * @param txRequest - The signed transaction request.
- * @param previousKernel - The previous kernel data (dummy if this is the first kernel in the chain).
- * @param privateCallData - The private call data.
- * @param firstIteration - Whether this is the first iteration of the private kernel.
- * @returns The proof of the private kernel.
- */
-export function privateKernelProve(
-  wasm: CircuitsWasm,
-  txRequest: TxRequest,
-  previousKernel: PreviousKernelData,
-  privateCallData: PrivateCallData,
-  firstIteration: boolean,
-): Buffer {
-  wasm.call('pedersen__init');
-  const txRequestBuffer = txRequest.toBuffer();
-  const previousKernelBuffer = previousKernel.toBuffer();
-  const privateCallDataBuffer = privateCallData.toBuffer();
-  const previousKernelBufferOffset = txRequestBuffer.length;
-  const privateCallDataOffset = previousKernelBufferOffset + previousKernelBuffer.length;
-  // This is an unused pointer argument at the moment.
-  const provingKeyOffset = privateCallDataOffset + privateCallDataBuffer.length;
-  wasm.writeMemory(0, txRequestBuffer);
-  wasm.writeMemory(previousKernelBufferOffset, previousKernelBuffer);
-  wasm.writeMemory(privateCallDataOffset, privateCallDataBuffer);
-
-  const proofOutputAddressPtr = wasm.call('bbmalloc', 4);
-  const proofSize = wasm.call(
-    'private_kernel__prove',
-    0,
-    previousKernelBufferOffset,
-    privateCallDataOffset,
-    provingKeyOffset,
-    firstIteration,
-    proofOutputAddressPtr,
-  );
-  // for whenever we actually use this method, we need to do proper error handling in C++ via bberg.
-  const address = uint8ArrayToNum(wasm.getMemorySlice(proofOutputAddressPtr, proofOutputAddressPtr + 4));
-  const proof = Buffer.from(wasm.getMemorySlice(address, address + proofSize));
-  wasm.call('bbfree', proofOutputAddressPtr);
-  wasm.call('bbfree', address);
-  return proof;
-}