feat(proofs): make preferred witness type in circuit's genProof function

Remove isArm check in circuits and instead accept a parameter to decide which witness type to use.
Made appropriate changes in tests and cli

circuits/ts/index.ts

@@ -1,2 +1,2 @@
 export { genProof, verifyProof, extractVk } from "./proofs";
-export { isArm, cleanThreads } from "./utils";
+export { cleanThreads } from "./utils";

circuits/ts/proofs.ts

@@ -1,10 +1,10 @@
-import { readFileSync, writeFileSync, unlinkSync, existsSync, mkdirSync, rmdirSync } from "fs";
 import path from "path";
+import fs from "fs";
 import { execSync } from "child_process";
 import { tmpdir } from "os";
 import { zKey, groth16, FullProveResult, PublicSignals, Groth16Proof, ISnarkJSVerificationKey } from "snarkjs";
 import { stringifyBigInts } from "maci-crypto";
-import { cleanThreads, isArm } from "./utils";
+import { cleanThreads } from "./utils";
 import { IGenProofOptions } from "./types";
 
 /**
@@ -14,6 +14,7 @@ import { IGenProofOptions } from "./types";
  * snark and a WASM witness
  * @param inputs - the inputs to the circuit
  * @param zkeyPath - the path to the zkey
+ * @param useWasm - whether we want to use the wasm witness or not
  * @param rapidsnarkExePath - the path to the rapidnsark binary
  * @param witnessExePath - the path to the compiled witness binary
  * @param wasmPath - the path to the wasm witness
@@ -23,20 +24,24 @@ import { IGenProofOptions } from "./types";
 export const genProof = async ({
   inputs,
   zkeyPath,
+  useWasm,
   rapidsnarkExePath,
   witnessExePath,
   wasmPath,
   silent = false,
 }: IGenProofOptions): Promise<FullProveResult> => {
-  // if we are running on an arm chip we can use snarkjs directly
-  if (isArm()) {
+  // if we want to use a wasm witness we use snarkjs
+  if (useWasm) {
+    if (!wasmPath && !fs.existsSync(wasmPath)) {
+      throw new Error("wasmPath must be specified and valid");
+    }
     const { proof, publicSignals } = await groth16.fullProve(inputs, wasmPath, zkeyPath);
     return { proof, publicSignals };
   }
   // intel chip flow (use rapidnsark)
   // Create tmp directory
   const tmpPath = path.resolve(tmpdir(), `tmp-${Date.now()}`);
-  mkdirSync(tmpPath, { recursive: true });
+  fs.mkdirSync(tmpPath, { recursive: true });
 
   const inputJsonPath = path.resolve(tmpPath, "input.json");
   const outputWtnsPath = path.resolve(tmpPath, "output.wtns");
@@ -45,14 +50,14 @@ export const genProof = async ({
 
   // Write input.json
   const jsonData = JSON.stringify(stringifyBigInts(inputs));
-  writeFileSync(inputJsonPath, jsonData);
+  fs.writeFileSync(inputJsonPath, jsonData);
 
   // Generate the witness
   const witnessGenCmd = `${witnessExePath} ${inputJsonPath} ${outputWtnsPath}`;
 
   execSync(witnessGenCmd, { stdio: silent ? "ignore" : "pipe" });
 
-  if (!existsSync(outputWtnsPath)) {
+  if (!fs.existsSync(outputWtnsPath)) {
     throw new Error("Error executing " + witnessGenCmd);
   }
 
@@ -61,19 +66,20 @@ export const genProof = async ({
 
   execSync(proofGenCmd, { stdio: silent ? "ignore" : "pipe" });
 
-  if (!existsSync(proofJsonPath)) {
+  if (!fs.existsSync(proofJsonPath)) {
     throw new Error("Error executing " + proofGenCmd);
   }
 
   // Read the proof and public inputs
-  const proof = JSON.parse(readFileSync(proofJsonPath).toString()) as Groth16Proof;
-  const publicSignals = JSON.parse(readFileSync(publicJsonPath).toString()) as PublicSignals;
+  const proof = JSON.parse(fs.readFileSync(proofJsonPath).toString()) as Groth16Proof;
+  const publicSignals = JSON.parse(fs.readFileSync(publicJsonPath).toString()) as PublicSignals;
 
   // remove all artifacts
-  for (const f of [proofJsonPath, publicJsonPath, inputJsonPath, outputWtnsPath]) if (existsSync(f)) unlinkSync(f);
+  for (const f of [proofJsonPath, publicJsonPath, inputJsonPath, outputWtnsPath])
+    if (fs.existsSync(f)) fs.unlinkSync(f);
 
   // remove tmp directory
-  rmdirSync(tmpPath);
+  fs.rmdirSync(tmpPath);
 
   return { proof, publicSignals };
 };

circuits/ts/types.ts

@@ -6,6 +6,7 @@ import { CircuitInputs } from "maci-core";
 export interface IGenProofOptions {
   inputs: CircuitInputs;
   zkeyPath: string;
+  useWasm: boolean;
   rapidsnarkExePath?: string;
   witnessExePath?: string;
   wasmPath?: string;

circuits/ts/utils.ts

@@ -1,13 +1,3 @@
-import { arch } from "os";
-
-/**
- * Check if we are running on an arm chip
- * @returns whether we are running on an arm chip
- */
-export const isArm = (): boolean => {
-  return arch().includes("arm");
-};
-
 /*
  * https://github.com/iden3/snarkjs/issues/152
  * Need to cleanup the threads to avoid stalling

cli/tests/e2e.subsidy.test.ts

@@ -39,8 +39,7 @@ import {
   testTallyVotesWasmPath,
   testTallyVotesWitnessPath,
 } from "./constants";
-import { cleanSubsidy } from "./utils";
-import { isArm } from "maci-circuits";
+import { cleanSubsidy, isArm } from "./utils";
 import { genRandomSalt } from "maci-crypto";
 import { DeployedContracts, PollContracts } from "../ts/utils";
 

cli/tests/e2e.test.ts

@@ -36,8 +36,7 @@ import {
   testTallyVotesWasmPath,
   testTallyVotesWitnessPath,
 } from "./constants";
-import { cleanVanilla } from "./utils";
-import { isArm } from "maci-circuits";
+import { cleanVanilla, isArm } from "./utils";
 import { DeployedContracts, PollContracts } from "../ts/utils";
 import { Keypair } from "maci-domainobjs";
 import { genRandomSalt } from "maci-crypto";

cli/tests/keyChange.test.ts

@@ -1,4 +1,3 @@
-import { isArm } from "maci-circuits";
 import {
   deploy,
   deployPoll,
@@ -32,7 +31,7 @@ import {
   testTallyVotesWitnessPath,
 } from "./constants";
 import { Keypair } from "maci-domainobjs";
-import { cleanVanilla } from "./utils";
+import { cleanVanilla, isArm } from "./utils";
 import { readFileSync } from "fs";
 import { expect } from "chai";
 import { genRandomSalt } from "maci-crypto";

cli/tests/utils.ts

@@ -1,5 +1,7 @@
 import { existsSync, readdirSync, rmSync } from "fs";
-import { join } from "path";
+import { arch } from "os";
+
+import path from "path";
 
 /**
  * Test utility to clean up the proofs directory
@@ -8,7 +10,7 @@ import { join } from "path";
 export const cleanVanilla = () => {
   const files = readdirSync("./proofs");
   for (const file of files) {
-    rmSync(join("./proofs", file));
+    rmSync(path.join("./proofs", file));
   }
   if (existsSync("./tally.json")) rmSync("./tally.json");
 };
@@ -21,3 +23,11 @@ export const cleanSubsidy = () => {
   cleanVanilla();
   if (existsSync("./subsidy.json")) rmSync("./subsidy.json");
 };
+
+/**
+ * Check if we are running on an arm chip
+ * @returns whether we are running on an arm chip
+ */
+export const isArm = (): boolean => {
+  return arch().includes("arm");
+};

cli/ts/commands/genProofs.ts

@@ -229,6 +229,7 @@ export const genProofs = async (
       const r = await genProof({
         inputs: circuitInputs,
         zkeyPath: processZkey,
+        useWasm,
         rapidsnarkExePath: rapidsnark,
         witnessExePath: processWitgen,
         wasmPath: processWasm,
@@ -288,6 +289,7 @@ export const genProofs = async (
         const r = await genProof({
           inputs: subsidyCircuitInputs,
           zkeyPath: subsidyZkey,
+          useWasm,
           rapidsnarkExePath: rapidsnark,
           witnessExePath: subsidyWitgen,
           wasmPath: subsidyWasm,
@@ -351,6 +353,7 @@ export const genProofs = async (
       const r = await genProof({
         inputs: tallyCircuitInputs,
         zkeyPath: tallyZkey,
+        useWasm,
         rapidsnarkExePath: rapidsnark,
         witnessExePath: tallyWitgen,
         wasmPath: tallyWasm,