support converting our rapidsnark proofs into gnark format (WIP)

crypto/zk/prover/prover_test.go

@@ -1,11 +1,19 @@
 package prover
 
 import (
+	"encoding/hex"
 	"encoding/json"
+	"fmt"
 	"log"
+	"math/big"
 	"os"
 	"testing"
 
+	"go.vocdoni.io/dvote/util"
+
+	"github.com/consensys/gnark-crypto/ecc/bn254"
+	"github.com/consensys/gnark-crypto/ecc/bn254/fp"
+	groth16_bn254 "github.com/consensys/gnark/backend/groth16/bn254"
 	qt "github.com/frankban/quicktest"
 )
 
@@ -135,3 +143,291 @@
 	err = wrongProof.Verify(vkey2)
 	qt.Assert(t, err, qt.IsNotNil)
 }
+
+func TestGnark(t *testing.T) {
+	// Generate proof
+	proof, _ := Prove(zkey, wasm, inputs)
+
+	t.Logf("%+v", prettyPrint(proof))
+
+	gnarkproof := ProofToGnarkProof(proof)
+
+	_ = sp1WitnessInput(inputs)
+
+	sp1proof := GnarkProofToSP1Proof(gnarkproof, WitnessInput{
+		"1234", // this should be the hash of the verification key (in gnark binary format) vk.hash_bn254().as_canonical_biguint()
+		"5678", // and this the hash of the SP1PublicValues public_values.hash_bn254()
+	})
+
+	t.Logf("%+v", prettyPrint(sp1proof))
+}
+
+func sp1WitnessInput(inputs []byte) WitnessInput {
+	witnessInput := WitnessInput{}
+	gnarkVK, err := parseVKForGnark(vkey)
+	if err != nil {
+		panic(err)
+	}
+	fmt.Printf("%+v", prettyPrint(gnarkVK))
+
+	witnessInput.VkeyHash = hashBN254(gnarkVK)            // TODO
+	witnessInput.CommitedValuesDigest = hashBN254(inputs) // TODO
+	return witnessInput
+}
+
+func hashBN254(any) string {
+	return "deadcode"
+}
+
+func prettyPrint(v interface{}) string {
+	// Convert the struct to a pretty JSON format
+	prettyJSON, err := json.MarshalIndent(v, "", "  ")
+	if err != nil {
+		panic(err)
+	}
+	return string(prettyJSON)
+}
+
+// Function to convert a hex string to a big.Int
+func hexToBigInt(hexStr string) (*big.Int, error) {
+	data, err := hex.DecodeString(util.TrimHex(hexStr))
+	if err != nil {
+		return nil, err
+	}
+	return new(big.Int).SetBytes(data), nil
+}
+
+func ProofToGnarkProof(proof *Proof) *groth16_bn254.Proof {
+	gnarkproof, err := convertToGnarkProof(proof.Data)
+	if err != nil {
+		log.Fatal(err)
+	}
+	return gnarkproof
+}
+
+// Convert ProofData to gnark-compatible Groth16 proof
+func convertToGnarkProof(pd ProofData) (*groth16_bn254.Proof, error) {
+	gnarkProof := &groth16_bn254.Proof{}
+
+	// Convert pi_a (G1) - Point A
+	aXBigInt, err := stringToBigInt(pd.A[0])
+	if err != nil {
+		return gnarkProof, err
+	}
+	aYBigInt, err := stringToBigInt(pd.A[1])
+	if err != nil {
+		return gnarkProof, err
+	}
+
+	// Initialize fr.Element for A point
+	var aX, aY fp.Element
+	aX.SetBigInt(aXBigInt)
+	aY.SetBigInt(aYBigInt)
+
+	gnarkProof.Ar = bn254.G1Affine{
+		X: aX,
+		Y: aY,
+	}
+
+	// Convert pi_b (G2) - Point B
+	bX0BigInt, err := stringToBigInt(pd.B[0][0])
+	if err != nil {
+		return gnarkProof, err
+	}
+	bX1BigInt, err := stringToBigInt(pd.B[0][1])
+	if err != nil {
+		return gnarkProof, err
+	}
+	bY0BigInt, err := stringToBigInt(pd.B[1][0])
+	if err != nil {
+		return gnarkProof, err
+	}
+	bY1BigInt, err := stringToBigInt(pd.B[1][1])
+	if err != nil {
+		return gnarkProof, err
+	}
+
+	// Initialize fr.Element for B points
+	var bX0, bX1, bY0, bY1 fp.Element
+	bX0.SetBigInt(bX0BigInt)
+	bX1.SetBigInt(bX1BigInt)
+	bY0.SetBigInt(bY0BigInt)
+	bY1.SetBigInt(bY1BigInt)
+
+	// Construct the G2 element for Bs (G2Affine expects fptower.E2 for both X and Y)
+	gnarkProof.Bs.X.A0 = bX0
+	gnarkProof.Bs.X.A1 = bX1
+	gnarkProof.Bs.Y.A0 = bY0
+	gnarkProof.Bs.Y.A1 = bY1
+
+	// Convert pi_c (G1) - Point C
+	cXBigInt, err := stringToBigInt(pd.C[0])
+	if err != nil {
+		return gnarkProof, err
+	}
+	cYBigInt, err := stringToBigInt(pd.C[1])
+	if err != nil {
+		return gnarkProof, err
+	}
+
+	// Initialize fr.Element for C point
+	var cX, cY fp.Element
+	cX.SetBigInt(cXBigInt)
+	cY.SetBigInt(cYBigInt)
+
+	gnarkProof.Krs.X = cX
+	gnarkProof.Krs.Y = cY
+
+	return gnarkProof, nil
+}
+
+// WitnessInput is copypasta from sp1
+type WitnessInput struct {
+	VkeyHash             string `json:"vkey_hash"`
+	CommitedValuesDigest string `json:"commited_values_digest"`
+}
+
+// SP1Proof is copypasta from sp1
+type SP1Proof struct {
+	PublicInputs [2]string `json:"public_inputs"`
+	EncodedProof string    `json:"encoded_proof"`
+	RawProof     string    `json:"raw_proof"`
+}
+
+func GnarkProofToSP1Proof(proof *groth16_bn254.Proof, witnessInput WitnessInput) SP1Proof {
+	var publicInputs [2]string
+	publicInputs[0] = witnessInput.VkeyHash
+	publicInputs[1] = witnessInput.CommitedValuesDigest
+
+	encodedProof := proof.MarshalSolidity()
+
+	return SP1Proof{
+		PublicInputs: publicInputs,
+		EncodedProof: hex.EncodeToString(encodedProof),
+		// RawProof:     hex.EncodeToString(proofBytes), // this field is uninteresting AFAIU
+	}
+}
+
+// Verification Key
+
+// vkJSON is the format of the verification key from go-rapidsnark, copypasta from
+// ~/go/pkg/mod/github.com/iden3/go-rapidsnark/verifier@v0.0.3/parser.go
+type vkJSON struct {
+	Alpha []string   `json:"vk_alpha_1"`
+	Beta  [][]string `json:"vk_beta_2"`
+	Gamma [][]string `json:"vk_gamma_2"`
+	Delta [][]string `json:"vk_delta_2"`
+	IC    [][]string `json:"IC"`
+}
+
+// Converts hexadecimal string to a field element (fr.Element)
+func hexToFieldElement(hexStr string) (fp.Element, error) {
+	var elem fp.Element
+	bigInt, success := new(big.Int).SetString(hexStr, 10) // assuming decimal strings
+	if !success {
+		return elem, fmt.Errorf("invalid field element: %s", hexStr)
+	}
+	elem.SetBigInt(bigInt)
+	return elem, nil
+}
+
+// Converts a slice of string to a G1 point
+func stringToG1(coords []string) (bn254.G1Affine, error) {
+	var p bn254.G1Affine
+	if len(coords) != 3 {
+		return p, fmt.Errorf("invalid G1 coordinates: %v", coords)
+	}
+	x, err := hexToFieldElement(coords[0])
+	if err != nil {
+		return p, err
+	}
+	y, err := hexToFieldElement(coords[1])
+	if err != nil {
+		return p, err
+	}
+	p.X = x
+	p.Y = y
+	return p, nil
+}
+
+// Converts a slice of string to a G2 point
+func stringToG2(coords [][]string) (bn254.G2Affine, error) {
+	var p bn254.G2Affine
+	if len(coords) != 3 {
+		return p, fmt.Errorf("invalid G2 coordinates")
+	}
+
+	// Convert X (A0, A1)
+	xA0, err := hexToFieldElement(coords[0][0])
+	if err != nil {
+		return p, err
+	}
+	xA1, err := hexToFieldElement(coords[0][1])
+	if err != nil {
+		return p, err
+	}
+
+	// Convert Y (A0, A1)
+	yA0, err := hexToFieldElement(coords[1][0])
+	if err != nil {
+		return p, err
+	}
+	yA1, err := hexToFieldElement(coords[1][1])
+	if err != nil {
+		return p, err
+	}
+
+	p.X.A0, p.X.A1 = xA0, xA1
+	p.Y.A0, p.Y.A1 = yA0, yA1
+	return p, nil
+}
+
+// Parses the vkJSON into gnark's groth16.VerifyingKey
+func parseVKForGnark(vkjson []byte) (*groth16_bn254.VerifyingKey, error) {
+	var vkStr vkJSON
+	err := json.Unmarshal(vkjson, &vkStr)
+	if err != nil {
+		return nil, fmt.Errorf("Error parsing verification key JSON: %w", err)
+	}
+
+	vk := new(groth16_bn254.VerifyingKey)
+
+	// Parse Alpha (G1 point)
+	alpha, err := stringToG1(vkStr.Alpha)
+	if err != nil {
+		return nil, err
+	}
+	vk.G1.Alpha = alpha
+
+	// Parse Beta (G2 point)
+	beta, err := stringToG2(vkStr.Beta)
+	if err != nil {
+		return nil, err
+	}
+	vk.G2.Beta = beta
+
+	// Parse Gamma (G2 point)
+	gamma, err := stringToG2(vkStr.Gamma)
+	if err != nil {
+		return nil, err
+	}
+	vk.G2.Gamma = gamma
+
+	// Parse Delta (G2 point)
+	delta, err := stringToG2(vkStr.Delta)
+	if err != nil {
+		return nil, err
+	}
+	vk.G2.Delta = delta
+
+	// Parse IC (G1 points array)
+	for _, icCoords := range vkStr.IC {
+		icPoint, err := stringToG1(icCoords)
+		if err != nil {
+			return nil, err
+		}
+		vk.G1.K = append(vk.G1.K, icPoint)
+	}
+
+	return vk, nil
+}

go.mod

@@ -14,6 +14,8 @@ require (
 	github.com/cometbft/cometbft v1.0.0-alpha.1
 	github.com/cometbft/cometbft-db v0.9.1
 	github.com/cometbft/cometbft/api v1.0.0-alpha.1
+	github.com/consensys/gnark v0.10.0
+	github.com/consensys/gnark-crypto v0.12.2-0.20240215234832-d72fcb379d3e
 	github.com/ethereum/go-ethereum v1.14.7
 	github.com/fatih/color v1.16.0
 	github.com/frankban/quicktest v1.14.6
@@ -88,7 +90,6 @@ require (
 	github.com/cockroachdb/redact v1.1.5 // indirect
 	github.com/cockroachdb/tokenbucket v0.0.0-20230807174530-cc333fc44b06 // indirect
 	github.com/consensys/bavard v0.1.13 // indirect
-	github.com/consensys/gnark-crypto v0.12.1 // indirect
 	github.com/containerd/cgroups v1.1.0 // indirect
 	github.com/coreos/go-systemd/v22 v22.5.0 // indirect
 	github.com/cosmos/gogoproto v1.5.0 // indirect
@@ -115,6 +116,7 @@ require (
 	github.com/flynn/noise v1.1.0 // indirect
 	github.com/francoispqt/gojay v1.2.13 // indirect
 	github.com/fsnotify/fsnotify v1.7.0 // indirect
+	github.com/fxamacker/cbor/v2 v2.5.0 // indirect
 	github.com/gabriel-vasile/mimetype v1.4.3 // indirect
 	github.com/getsentry/sentry-go v0.27.0 // indirect
 	github.com/go-chi/chi v4.1.2+incompatible // indirect
@@ -301,6 +303,7 @@ require (
 	github.com/whyrusleeping/go-keyspace v0.0.0-20160322163242-5b898ac5add1 // indirect
 	github.com/whyrusleeping/go-sysinfo v0.0.0-20190219211824-4a357d4b90b1 // indirect
 	github.com/whyrusleeping/multiaddr-filter v0.0.0-20160516205228-e903e4adabd7 // indirect
+	github.com/x448/float16 v0.8.4 // indirect
 	github.com/xdg-go/pbkdf2 v1.0.0 // indirect
 	github.com/xdg-go/scram v1.1.2 // indirect
 	github.com/xdg-go/stringprep v1.0.4 // indirect

go.sum

@@ -236,9 +236,11 @@ github.com/cometbft/cometbft/api v1.0.0-alpha.1/go.mod h1:5vJTKMdvGufLjyQ0fqSfZ1
 github.com/consensys/bavard v0.1.8-0.20210406032232-f3452dc9b572/go.mod h1:Bpd0/3mZuaj6Sj+PqrmIquiOKy397AKGThQPaGzNXAQ=
 github.com/consensys/bavard v0.1.13 h1:oLhMLOFGTLdlda/kma4VOJazblc7IM5y5QPd2A/YjhQ=
 github.com/consensys/bavard v0.1.13/go.mod h1:9ItSMtA/dXMAiL7BG6bqW2m3NdSEObYWoH223nGHukI=
+github.com/consensys/gnark v0.10.0 h1:yhi6ThoeFP7WrH8zQDaO56WVXe9iJEBSkfrZ9PZxabw=
+github.com/consensys/gnark v0.10.0/go.mod h1:VJU5JrrhZorbfDH+EUjcuFWr2c5z19tHPh8D6KVQksU=
 github.com/consensys/gnark-crypto v0.4.1-0.20210426202927-39ac3d4b3f1f/go.mod h1:815PAHg3wvysy0SyIqanF8gZ0Y1wjk/hrDHD/iT88+Q=
-github.com/consensys/gnark-crypto v0.12.1 h1:lHH39WuuFgVHONRl3J0LRBtuYdQTumFSDtJF7HpyG8M=
-github.com/consensys/gnark-crypto v0.12.1/go.mod h1:v2Gy7L/4ZRosZ7Ivs+9SfUDr0f5UlG+EM5t7MPHiLuY=
+github.com/consensys/gnark-crypto v0.12.2-0.20240215234832-d72fcb379d3e h1:MKdOuCiy2DAX1tMp2YsmtNDaqdigpY6B5cZQDJ9BvEo=
+github.com/consensys/gnark-crypto v0.12.2-0.20240215234832-d72fcb379d3e/go.mod h1:wKqwsieaKPThcFkHe0d0zMsbHEUWFmZcG7KBCse210o=
 github.com/containerd/cgroups v0.0.0-20201119153540-4cbc285b3327/go.mod h1:ZJeTFisyysqgcCdecO57Dj79RfL0LNeGiFUqLYQRYLE=
 github.com/containerd/cgroups v1.1.0 h1:v8rEWFl6EoqHB+swVNjVoCJE8o3jX7e8nqBGPLaDFBM=
 github.com/containerd/cgroups v1.1.0/go.mod h1:6ppBcbh/NOOUU+dMKrykgaBnK9lCIBxHqJDGwsa1mIw=
@@ -378,6 +380,8 @@ github.com/fsnotify/fsnotify v1.4.9/go.mod h1:znqG4EE+3YCdAaPaxE2ZRY/06pZUdp0tY4
 github.com/fsnotify/fsnotify v1.5.4/go.mod h1:OVB6XrOHzAwXMpEM7uPOzcehqUV2UqJxmVXmkdnm1bU=
 github.com/fsnotify/fsnotify v1.7.0 h1:8JEhPFa5W2WU7YfeZzPNqzMP6Lwt7L2715Ggo0nosvA=
 github.com/fsnotify/fsnotify v1.7.0/go.mod h1:40Bi/Hjc2AVfZrqy+aj+yEI+/bRxZnMJyTJwOpGvigM=
+github.com/fxamacker/cbor/v2 v2.5.0 h1:oHsG0V/Q6E/wqTS2O1Cozzsy69nqCiguo5Q1a1ADivE=
+github.com/fxamacker/cbor/v2 v2.5.0/go.mod h1:TA1xS00nchWmaBnEIxPSE5oHLuJBAVvqrtAnWBwBCVo=
 github.com/gabriel-vasile/mimetype v1.4.3 h1:in2uUcidCuFcDKtdcBxlR0rJ1+fsokWf+uqxgUFjbI0=
 github.com/gabriel-vasile/mimetype v1.4.3/go.mod h1:d8uq/6HKRL6CGdk+aubisF/M5GcPfT7nKyLpA0lbSSk=
 github.com/gballet/go-libpcsclite v0.0.0-20190607065134-2772fd86a8ff/go.mod h1:x7DCsMOv1taUwEWCzT4cmDeAkigA5/QCwUodaVOe8Ww=
@@ -665,6 +669,10 @@ github.com/influxdata/promql/v2 v2.12.0/go.mod h1:fxOPu+DY0bqCTCECchSRtWfc+0X19y
 github.com/influxdata/roaring v0.4.13-0.20180809181101-fc520f41fab6/go.mod h1:bSgUQ7q5ZLSO+bKBGqJiCBGAl+9DxyW63zLTujjUlOE=
 github.com/influxdata/tdigest v0.0.0-20181121200506-bf2b5ad3c0a9/go.mod h1:Js0mqiSBE6Ffsg94weZZ2c+v/ciT8QRHFOap7EKDrR0=
 github.com/influxdata/usage-client v0.0.0-20160829180054-6d3895376368/go.mod h1:Wbbw6tYNvwa5dlB6304Sd+82Z3f7PmVZHVKU637d4po=
+github.com/ingonyama-zk/icicle v0.0.0-20230928131117-97f0079e5c71 h1:YxI1RTPzpFJ3MBmxPl3Bo0F7ume7CmQEC1M9jL6CT94=
+github.com/ingonyama-zk/icicle v0.0.0-20230928131117-97f0079e5c71/go.mod h1:kAK8/EoN7fUEmakzgZIYdWy1a2rBnpCaZLqSHwZWxEk=
+github.com/ingonyama-zk/iciclegnark v0.1.0 h1:88MkEghzjQBMjrYRJFxZ9oR9CTIpB8NG2zLeCJSvXKQ=
+github.com/ingonyama-zk/iciclegnark v0.1.0/go.mod h1:wz6+IpyHKs6UhMMoQpNqz1VY+ddfKqC/gRwR/64W6WU=
 github.com/ipfs-shipyard/nopfs v0.0.12 h1:mvwaoefDF5VI9jyvgWCmaoTJIJFAfrbyQV5fJz35hlk=
 github.com/ipfs-shipyard/nopfs v0.0.12/go.mod h1:mQyd0BElYI2gB/kq/Oue97obP4B3os4eBmgfPZ+hnrE=
 github.com/ipfs-shipyard/nopfs/ipfs v0.13.2-0.20231027223058-cde3b5ba964c h1:7UynTbtdlt+w08ggb1UGLGaGjp1mMaZhoTZSctpn5Ak=
@@ -1506,6 +1514,8 @@ github.com/whyrusleeping/multiaddr-filter v0.0.0-20160516205228-e903e4adabd7/go.
 github.com/willf/bitset v1.1.3/go.mod h1:RjeCKbqT1RxIR/KWY6phxZiaY1IyutSBfGjNPySAYV4=
 github.com/wsddn/go-ecdh v0.0.0-20161211032359-48726bab9208/go.mod h1:IotVbo4F+mw0EzQ08zFqg7pK3FebNXpaMsRy2RT+Ees=
 github.com/x-cray/logrus-prefixed-formatter v0.5.2/go.mod h1:2duySbKsL6M18s5GU7VPsoEPHyzalCE06qoARUCeBBE=
+github.com/x448/float16 v0.8.4 h1:qLwI1I70+NjRFUR3zs1JPUCgaCXSh3SW62uAKT1mSBM=
+github.com/x448/float16 v0.8.4/go.mod h1:14CWIYCyZA/cWjXOioeEpHeN/83MdbZDRQHoFcYsOfg=
 github.com/xdg-go/pbkdf2 v1.0.0 h1:Su7DPu48wXMwC3bs7MCNG+z4FhcyEuz5dlvchbq0B0c=
 github.com/xdg-go/pbkdf2 v1.0.0/go.mod h1:jrpuAogTd400dnrH08LKmI/xc1MbPOebTwRqcT5RDeI=
 github.com/xdg-go/scram v1.1.2 h1:FHX5I5B4i4hKRVRBCFRxq1iQRej7WO3hhBuJf+UUySY=