Witness compatible with snarkjs

[ItsFunny]

Hi, Great Project
I have a question about generating the witness , Can we generate the witness which is compatible with snarkjs?

[ItsFunny]

For example :
api or cmd line : Generate the witness and save to witness.wtns

[rymnc]

Hey @ItsFunny, sorry for the late ping. While it isn't possible currently to export a witness compatible with snarkjs, we can export the public inputs and the proof, using the method described here -

zerokit/rln/src/public.rs

Lines 1625 to 1740 in 4180a2b

	fn fq_from_str(s: String) -> ark_bn254::Fq {
	ark_bn254::Fq::from_str(&s).unwrap()
	}
	fn g1_from_str(g1: &[String]) -> ark_bn254::G1Affine {
	let x = fq_from_str(g1[0].clone());
	let y = fq_from_str(g1[1].clone());
	let z = fq_from_str(g1[2].clone());
	ark_bn254::G1Affine::from(ark_bn254::G1Projective::new(x, y, z))
	}
	fn g2_from_str(g2: &[Vec<String>]) -> ark_bn254::G2Affine {
	let c0 = fq_from_str(g2[0][0].clone());
	let c1 = fq_from_str(g2[0][1].clone());
	let x = ark_bn254::Fq2::new(c0, c1);
	let c0 = fq_from_str(g2[1][0].clone());
	let c1 = fq_from_str(g2[1][1].clone());
	let y = ark_bn254::Fq2::new(c0, c1);
	let c0 = fq_from_str(g2[2][0].clone());
	let c1 = fq_from_str(g2[2][1].clone());
	let z = ark_bn254::Fq2::new(c0, c1);
	ark_bn254::G2Affine::from(ark_bn254::G2Projective::new(x, y, z))
	}
	fn value_to_string_vec(value: &Value) -> Vec<String> {
	value
	.as_array()
	.unwrap()
	.into_iter()
	.map(|val| val.as_str().unwrap().to_string())
	.collect()
	}
	#[test]
	fn test_groth16_proof_hardcoded() {
	let tree_height = TEST_TREE_HEIGHT;
	let input_buffer =
	Cursor::new(json!({ "resources_folder": TEST_RESOURCES_FOLDER }).to_string());
	let rln = RLN::new(tree_height, input_buffer).unwrap();
	let valid_snarkjs_proof = json!({
	"pi_a": [
	"4470527391588441860193200161084455226340491373346283552408949960585113822665",
	"17066173901974939377117728437830216011764222423156801199965800887938087190121",
	"1"
	],
	"pi_b": [
	[
	"15972566464269406830925988363875489807783626890329856187767783138745533264635",
	"14937519511565349355063307001263881540320664095110809840110097755110649950560"
	],
	[
	"533488241215365262498062426054646750918758165791898421060280269581011723961",
	"9035874337973494769294028746597715861635666159729389919309920308765805688602"
	],
	[
	"1",
	"0"
	]
	],
	"pi_c": [
	"20620241453393708332486848754039748595639801912969370960546027260091108922454",
	"20580342189093698831710267260567759683930279312746044733195059538431965163807",
	"1"
	],
	"protocol": "groth16",
	"curve": "bn128"
	});
	let valid_ark_proof = ArkProof {
	a: g1_from_str(&value_to_string_vec(&valid_snarkjs_proof["pi_a"])),
	b: g2_from_str(
	&valid_snarkjs_proof["pi_b"]
	.as_array()
	.unwrap()
	.iter()
	.map(|item| value_to_string_vec(item))
	.collect::<Vec<Vec<String>>>(),
	),
	c: g1_from_str(&value_to_string_vec(&valid_snarkjs_proof["pi_c"])),
	};
	let valid_proof_values = RLNProofValues {
	x: str_to_fr(
	"16401008481486069296141645075505218976370369489687327284155463920202585288271",
	10,
	)
	.unwrap(),
	external_nullifier: str_to_fr(
	"8502402278351299594663821509741133196466235670407051417832304486953898514733",
	10,
	)
	.unwrap(),
	y: str_to_fr(
	"9102791780887227194595604713537772536258726662792598131262022534710887343694",
	10,
	)
	.unwrap(),
	root: str_to_fr(
	"20645213238265527935869146898028115621427162613172918400241870500502509785943",
	10,
	)
	.unwrap(),
	nullifier: str_to_fr(
	"21074405743803627666274838159589343934394162804826017440941339048886754734203",
	10,
	)
	.unwrap(),
	};
	let verified = verify_proof(&rln.verification_key, &valid_ark_proof, &valid_proof_values);
	assert!(verified.unwrap());
	}