add wasm snark proof verification function (Pinocchio)

README.md

@@ -41,7 +41,7 @@ Improvements from the minimal implementation:
 - [x] Groth16
 - [ ] multiple optimizations
 - [x] wasm proof generation
-- [ ] wasm proof verification
+- [x] wasm proof verification
 
 ## WASM usage
 Ongoing experimentation with go-snark compiled to wasm: https://github.com/arnaucube/go-snark/tree/master/wasm

wasm/README.md

@@ -12,15 +12,7 @@ Add the file `wasm_exec.js` in the directory:
 cp "$(go env GOROOT)/misc/wasm/wasm_exec.js" .
 ```
 
-Call the library from javascript:
-```js
-let r = generateProofs(
-	JSON.stringify(circuit),
-	JSON.stringify(setup),
-	JSON.stringify(px),
-	JSON.stringify(inputs),
-);
-```
+To see the usage from javascript, check `index.js` file.
 
 Run the http server that allows to load the `.wasm` file:
 ```

wasm/go-snark-wasm-wrapper.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"encoding/json"
+	"math/big"
 	"syscall/js"
 
 	"github.com/arnaucube/go-snark"
@@ -11,15 +12,14 @@ import (
 
 func main() {
 	c := make(chan struct{}, 0)
-
 	println("WASM Go Initialized")
-	// register functions
 	registerCallbacks()
 	<-c
 }
 
 func registerCallbacks() {
 	js.Global().Set("generateProofs", js.FuncOf(generateProofs))
+	js.Global().Set("verifyProofs", js.FuncOf(verifyProofs))
 }
 
 func generateProofs(this js.Value, i []js.Value) interface{} {
@@ -89,3 +89,56 @@ func generateProofs(this js.Value, i []js.Value) interface{} {
 	println("proofJson", string(proofJson))
 	return js.ValueOf(string(proofJson))
 }
+
+func verifyProofs(this js.Value, i []js.Value) interface{} {
+	var circuitStr utils.CircuitString
+	err := json.Unmarshal([]byte(i[0].String()), &circuitStr)
+	if err != nil {
+		println(i[0].String())
+		println("error parsing circuit from stringified json")
+	}
+	circuit, err := utils.CircuitFromString(circuitStr)
+	if err != nil {
+		println("error " + err.Error())
+	}
+
+	var setupStr utils.SetupString
+	println(i[1].String())
+	err = json.Unmarshal([]byte(i[1].String()), &setupStr)
+	if err != nil {
+		println("error parsing setup from stringified json")
+	}
+	setup, err := utils.SetupFromString(setupStr)
+	if err != nil {
+		println("error " + err.Error())
+	}
+
+	var proofStr utils.ProofString
+	err = json.Unmarshal([]byte(i[2].String()), &proofStr)
+	if err != nil {
+		println(i[0].String())
+		println("error parsing proof from stringified json")
+	}
+	proof, err := utils.ProofFromString(proofStr)
+	if err != nil {
+		println("error " + err.Error())
+	}
+
+	var publicInputs []*big.Int
+	err = json.Unmarshal([]byte(i[3].String()), &publicInputs)
+	if err != nil {
+		println(i[0].String())
+		println("error parsing publicInputs from stringified json")
+	}
+
+	verified := snark.VerifyProof(circuit, setup, proof, publicInputs, false)
+	if err != nil {
+		println("error verifiyng proof", err)
+	}
+	verifiedJson, err := json.Marshal(verified)
+	if err != nil {
+		println("error marshal verified to json", err)
+	}
+	println("verifiedJson", string(verifiedJson))
+	return js.ValueOf(string(verifiedJson))
+}

wasm/index.html

@@ -14,6 +14,7 @@
 	<button onClick="callGenerateProof();">Generate Proof</button>
 	<textarea id="proofResult" rows="15" style="width: 80%;">
 	</textarea>
+	<button onClick="callVerifyProof();">Verify Proof</button>
 	<script src="index.js"></script>
 </body>
 </html>

wasm/utils/utils.go

@@ -169,6 +169,14 @@ func SetupToString(setup snark.Setup) SetupString {
 	s.Pk.Bp = Array3BigIntToString(setup.Pk.Bp)
 	s.Pk.Cp = Array3BigIntToString(setup.Pk.Cp)
 	s.Pk.Z = ArrayBigIntToString(setup.Pk.Z)
+	s.Vk.Vka = BigInt32ToString(setup.Vk.Vka)
+	s.Vk.Vkb = BigInt3ToString(setup.Vk.Vkb)
+	s.Vk.Vkc = BigInt32ToString(setup.Vk.Vkc)
+	s.Vk.IC = Array3BigIntToString(setup.Vk.IC)
+	s.Vk.G1Kbg = BigInt3ToString(setup.Vk.G1Kbg)
+	s.Vk.G2Kbg = BigInt32ToString(setup.Vk.G2Kbg)
+	s.Vk.G2Kg = BigInt32ToString(setup.Vk.G2Kg)
+	s.Vk.Vkz = BigInt32ToString(setup.Vk.Vkz)
 	return s
 }
 func SetupFromString(s SetupString) (snark.Setup, error) {
@@ -214,6 +222,40 @@ func SetupFromString(s SetupString) (snark.Setup, error) {
 	if err != nil {
 		return o, err
 	}
+
+	o.Vk.Vka, err = String32ToBigInt(s.Vk.Vka)
+	if err != nil {
+		return o, err
+	}
+	o.Vk.Vkb, err = String3ToBigInt(s.Vk.Vkb)
+	if err != nil {
+		return o, err
+	}
+	o.Vk.Vkc, err = String32ToBigInt(s.Vk.Vkc)
+	if err != nil {
+		return o, err
+	}
+	o.Vk.IC, err = Array3StringToBigInt(s.Vk.IC)
+	if err != nil {
+		return o, err
+	}
+	o.Vk.G1Kbg, err = String3ToBigInt(s.Vk.G1Kbg)
+	if err != nil {
+		return o, err
+	}
+	o.Vk.G2Kbg, err = String32ToBigInt(s.Vk.G2Kbg)
+	if err != nil {
+		return o, err
+	}
+	o.Vk.G2Kg, err = String32ToBigInt(s.Vk.G2Kg)
+	if err != nil {
+		return o, err
+	}
+	o.Vk.Vkz, err = String32ToBigInt(s.Vk.Vkz)
+	if err != nil {
+		return o, err
+	}
+
 	return o, nil
 
 }