Fixed underconstrained in range check and added dummy mode to benchmark.go

benchmark.go

@@ -40,7 +40,7 @@ func (circuit *BenchmarkPlonky2VerifierCircuit) Define(api frontend.API) error {
 	return nil
 }
 
-func compileCircuit(plonky2Circuit string, profileCircuit bool, serialize bool, outputSolidity bool) (constraint.ConstraintSystem, groth16.ProvingKey, groth16.VerifyingKey) {
+func compileCircuit(plonky2Circuit string, profileCircuit bool, serialize bool, outputSolidity bool, dummy bool) (constraint.ConstraintSystem, groth16.ProvingKey, groth16.VerifyingKey) {
 	circuit := BenchmarkPlonky2VerifierCircuit{
 		plonky2CircuitName: plonky2Circuit,
 	}
@@ -76,9 +76,17 @@ func compileCircuit(plonky2Circuit string, profileCircuit bool, serialize bool,
 			fR1CS.Close()
 		}
 	*/
+	var pk groth16.ProvingKey
+	var vk groth16.VerifyingKey
 
 	fmt.Println("Running circuit setup", time.Now())
-	pk, vk, err := groth16.Setup(r1cs)
+	if dummy {
+		fmt.Println("Using dummy setup")
+		pk, err = groth16.DummySetup(r1cs)
+	} else {
+		fmt.Println("Using real setup")
+		pk, vk, err = groth16.Setup(r1cs)
+	}
 	if err != nil {
 		fmt.Println(err)
 		os.Exit(1)
@@ -132,6 +140,11 @@ func createProof(plonky2Circuit string, r1cs constraint.ConstraintSystem, pk gro
 		fProof.Close()
 	}
 
+	if vk == nil {
+		fmt.Println("vk is nil, means you're using dummy setup and we skip verification step")
+		return proof
+	}
+
 	fmt.Println("Verifying proof", time.Now())
 	err = groth16.Verify(proof, vk, publicWitness)
 	if err != nil {
@@ -187,6 +200,6 @@ func main() {
 		os.Exit(1)
 	}
 
-	r1cs, pk, vk := compileCircuit(*plonky2Circuit, *profileCircuit, *serialize, *outputSolidity)
+	r1cs, pk, vk := compileCircuit(*plonky2Circuit, *profileCircuit, *serialize, *outputSolidity, true)
 	createProof(*plonky2Circuit, r1cs, pk, vk, *serialize)
 }

goldilocks/base.go

@@ -323,8 +323,18 @@ func (p *GoldilocksApi) RangeCheck(x GoldilocksVariable) {
 		panic(err)
 	}
 
+	// We check that this is a valid decomposition of the Goldilock's element and range-check each limb.
 	mostSigBits := result[0]
 	leastSigBits := result[1]
+	p.api.AssertIsEqual(
+		p.api.Add(
+			p.api.Mul(mostSigBits, uint64(math.Pow(2, 32))),
+			leastSigBits,
+		),
+		x.Limb,
+	)
+	rangeChecker.Check(mostSigBits, 32)
+	rangeChecker.Check(leastSigBits, 32)
 
 	// If the most significant bits are all 1, then we need to check that the least significant bits are all zero
 	// in order for element to be less than the Goldilock's modulus.