Ag 21 vote proof implementation

README.md

@@ -6,6 +6,8 @@
 
 A confidentiality-first electronic voting system.
 
+_this is an experimental project, don't use it in production_
+
 ## About
 
 Agora is a voting platform based on the [Ethereum](https://ethereum.org/en/) public blockchain and a [Zero-Knowledge Proof](https://zkp.science/) cryptographic protocol.
@@ -150,9 +152,9 @@ Then run the script in order to register the Voter DEC into the DECsRegistry:
 `npx hardhat run election-scripts/register-dec.ts --network localhost`
 
 ### 5. The Public Authority / Admin creates a Municipality Election
-At this point we have the EOA credentials and the DEC for our voters, and the DECs are registered on the DECs Registry. It's time to create an election: as an example we implemented a smart contract for a municipality election, that elects the major and the council.
+At this point we have the EOA credentials and the DEC for our voters, and the DECs are registered on the DECs Registry. It's time to create an election: as an example we implemented a smart contract for a municipality election, that elects the mayor and the council.
 
-Now it's time to deploy the smart contract election and register parties, councilor and major candidates, parties coalitions in the municipality election contract, run the command: 
+Now it's time to deploy the smart contract election and register parties, councilor and mayor candidates, parties coalitions in the municipality election contract, run the command: 
 
 `npx hardhat run election-scripts/create-election.ts --network localhost`
 

contracts/DECsRegistry.sol

@@ -37,11 +37,6 @@ contract DECsRegistry {
         name = _name;
     }
 
-    /// @notice DECs REgistry name getter function
-    function getName() external view returns (string memory) {
-        return name;
-    }
-
     /// @notice this function is used by the third party authority to register a Voter's DEC in the registry
     function registerDEC(address dec, address voter) external onlyOwner {
         require(

contracts/MunicipalityElection.sol

@@ -10,12 +10,12 @@ import "./Election.sol";
 contract MunicipalityElection is Election {
     struct Candidate {
         string name;
-        string candidatesFor; // major or councilor
+        string candidatesFor; // mayor or councilor
     }
 
     /// @dev the string key of the map correspond tho the party name registered in the parties mapping
     struct Coalition {
-        Candidate majorCandidate;
+        Candidate mayorCandidate;
         string[] parties;
     }
 
@@ -88,7 +88,7 @@ contract MunicipalityElection is Election {
             count++;
         }
 
-        return (coalition.majorCandidate, partyNames);
+        return (coalition.mayorCandidate, partyNames);
     }
 
     /// @notice as first step, during the registration period the parties register their names and list of councilor candidates
@@ -121,9 +121,9 @@ contract MunicipalityElection is Election {
         partiesLength++;
     }
 
-    /// @notice in this second step, the parties registered compose coalitions and indicate a major candidate name. A coalition is composed by one or more parties.
+    /// @notice in this second step, the parties registered compose coalitions and indicate a mayor candidate name. A coalition is composed by one or more parties.
     function registerCoalition(
-        string memory majorCandidate,
+        string memory mayorCandidate,
         string[] memory coalitionParties
     ) external onlyOwner isRegistrationPeriod {
         require(
@@ -135,17 +135,17 @@ contract MunicipalityElection is Election {
             "One or more parties are already present in a registered coalition"
         );
         require(
-            !_isMajorCandidateAlreadyRegistered(majorCandidate),
-            "The major candidate is already registered with a coalition"
+            !_isMajorCandidateAlreadyRegistered(mayorCandidate),
+            "The mayor candidate is already registered with a coalition"
         );
 
         Candidate memory mcandidate = Candidate({
-            name: majorCandidate,
-            candidatesFor: "major"
+            name: mayorCandidate,
+            candidatesFor: "mayor"
         });
 
         Coalition memory newCoalition;
-        newCoalition.majorCandidate = mcandidate;
+        newCoalition.mayorCandidate = mcandidate;
         newCoalition.parties = coalitionParties;
 
         coalitions.push(newCoalition);
@@ -186,7 +186,7 @@ contract MunicipalityElection is Election {
         for (uint i = 0; i < coalitions.length; i++) {
             if (
                 keccak256(
-                    abi.encodePacked(coalitions[i].majorCandidate.name)
+                    abi.encodePacked(coalitions[i].mayorCandidate.name)
                 ) == keccak256(abi.encodePacked(candidateMajor))
             ) {
                 return true;

contracts/MunicipalityElectionVerifier.sol

@@ -0,0 +1,201 @@
+// This file is MIT Licensed.
+//
+// Copyright 2017 Christian Reitwiessner
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+// The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+pragma solidity ^0.8.0;
+library Pairing {
+    struct G1Point {
+        uint X;
+        uint Y;
+    }
+    // Encoding of field elements is: X[0] * z + X[1]
+    struct G2Point {
+        uint[2] X;
+        uint[2] Y;
+    }
+    /// @return the generator of G1
+    function P1() pure internal returns (G1Point memory) {
+        return G1Point(1, 2);
+    }
+    /// @return the generator of G2
+    function P2() pure internal returns (G2Point memory) {
+        return G2Point(
+            [10857046999023057135944570762232829481370756359578518086990519993285655852781,
+             11559732032986387107991004021392285783925812861821192530917403151452391805634],
+            [8495653923123431417604973247489272438418190587263600148770280649306958101930,
+             4082367875863433681332203403145435568316851327593401208105741076214120093531]
+        );
+    }
+    /// @return the negation of p, i.e. p.addition(p.negate()) should be zero.
+    function negate(G1Point memory p) pure internal returns (G1Point memory) {
+        // The prime q in the base field F_q for G1
+        uint q = 21888242871839275222246405745257275088696311157297823662689037894645226208583;
+        if (p.X == 0 && p.Y == 0)
+            return G1Point(0, 0);
+        return G1Point(p.X, q - (p.Y % q));
+    }
+    /// @return r the sum of two points of G1
+    function addition(G1Point memory p1, G1Point memory p2) internal view returns (G1Point memory r) {
+        uint[4] memory input;
+        input[0] = p1.X;
+        input[1] = p1.Y;
+        input[2] = p2.X;
+        input[3] = p2.Y;
+        bool success;
+        assembly {
+            success := staticcall(sub(gas(), 2000), 6, input, 0xc0, r, 0x60)
+            // Use "invalid" to make gas estimation work
+            switch success case 0 { invalid() }
+        }
+        require(success);
+    }
+
+
+    /// @return r the product of a point on G1 and a scalar, i.e.
+    /// p == p.scalar_mul(1) and p.addition(p) == p.scalar_mul(2) for all points p.
+    function scalar_mul(G1Point memory p, uint s) internal view returns (G1Point memory r) {
+        uint[3] memory input;
+        input[0] = p.X;
+        input[1] = p.Y;
+        input[2] = s;
+        bool success;
+        assembly {
+            success := staticcall(sub(gas(), 2000), 7, input, 0x80, r, 0x60)
+            // Use "invalid" to make gas estimation work
+            switch success case 0 { invalid() }
+        }
+        require (success);
+    }
+    /// @return the result of computing the pairing check
+    /// e(p1[0], p2[0]) *  .... * e(p1[n], p2[n]) == 1
+    /// For example pairing([P1(), P1().negate()], [P2(), P2()]) should
+    /// return true.
+    function pairing(G1Point[] memory p1, G2Point[] memory p2) internal view returns (bool) {
+        require(p1.length == p2.length);
+        uint elements = p1.length;
+        uint inputSize = elements * 6;
+        uint[] memory input = new uint[](inputSize);
+        for (uint i = 0; i < elements; i++)
+        {
+            input[i * 6 + 0] = p1[i].X;
+            input[i * 6 + 1] = p1[i].Y;
+            input[i * 6 + 2] = p2[i].X[1];
+            input[i * 6 + 3] = p2[i].X[0];
+            input[i * 6 + 4] = p2[i].Y[1];
+            input[i * 6 + 5] = p2[i].Y[0];
+        }
+        uint[1] memory out;
+        bool success;
+        assembly {
+            success := staticcall(sub(gas(), 2000), 8, add(input, 0x20), mul(inputSize, 0x20), out, 0x20)
+            // Use "invalid" to make gas estimation work
+            switch success case 0 { invalid() }
+        }
+        require(success);
+        return out[0] != 0;
+    }
+    /// Convenience method for a pairing check for two pairs.
+    function pairingProd2(G1Point memory a1, G2Point memory a2, G1Point memory b1, G2Point memory b2) internal view returns (bool) {
+        G1Point[] memory p1 = new G1Point[](2);
+        G2Point[] memory p2 = new G2Point[](2);
+        p1[0] = a1;
+        p1[1] = b1;
+        p2[0] = a2;
+        p2[1] = b2;
+        return pairing(p1, p2);
+    }
+    /// Convenience method for a pairing check for three pairs.
+    function pairingProd3(
+            G1Point memory a1, G2Point memory a2,
+            G1Point memory b1, G2Point memory b2,
+            G1Point memory c1, G2Point memory c2
+    ) internal view returns (bool) {
+        G1Point[] memory p1 = new G1Point[](3);
+        G2Point[] memory p2 = new G2Point[](3);
+        p1[0] = a1;
+        p1[1] = b1;
+        p1[2] = c1;
+        p2[0] = a2;
+        p2[1] = b2;
+        p2[2] = c2;
+        return pairing(p1, p2);
+    }
+    /// Convenience method for a pairing check for four pairs.
+    function pairingProd4(
+            G1Point memory a1, G2Point memory a2,
+            G1Point memory b1, G2Point memory b2,
+            G1Point memory c1, G2Point memory c2,
+            G1Point memory d1, G2Point memory d2
+    ) internal view returns (bool) {
+        G1Point[] memory p1 = new G1Point[](4);
+        G2Point[] memory p2 = new G2Point[](4);
+        p1[0] = a1;
+        p1[1] = b1;
+        p1[2] = c1;
+        p1[3] = d1;
+        p2[0] = a2;
+        p2[1] = b2;
+        p2[2] = c2;
+        p2[3] = d2;
+        return pairing(p1, p2);
+    }
+}
+
+contract Verifier {
+    using Pairing for *;
+    struct VerifyingKey {
+        Pairing.G1Point alpha;
+        Pairing.G2Point beta;
+        Pairing.G2Point gamma;
+        Pairing.G2Point delta;
+        Pairing.G1Point[] gamma_abc;
+    }
+    struct Proof {
+        Pairing.G1Point a;
+        Pairing.G2Point b;
+        Pairing.G1Point c;
+    }
+    function verifyingKey() pure internal returns (VerifyingKey memory vk) {
+        vk.alpha = Pairing.G1Point(uint256(0x064dd210f698b357717d2fe569986299f56453bf2941dd8c3a1ffdfc92e7dd17), uint256(0x0fbda53bdb9c51dcc539929d1b8c1a1740ae04ca407960ff8944af4ab75ac554));
+        vk.beta = Pairing.G2Point([uint256(0x2f352011126bde35f3c31ac2fc80eaea822df967a0b8d5caea9f0cdf9649cba2), uint256(0x01e291253dad8dd579bfd79a938bbe719430157c0184a99f3b19e8252870d1ed)], [uint256(0x2ef849389b82b9c14197e2a64fab23d19a9cf255ff042e80157e8906c6cc2a8d), uint256(0x0f48407ce952385cd3920808f94a37ab84aeeee47f25461241e67afb5b0d18fe)]);
+        vk.gamma = Pairing.G2Point([uint256(0x06bfa70d59c01740ea4928f0f1fa9afcf51abec8b577dd91d9a25fbc9a5ee4e8), uint256(0x2eee2ed7c61141c810140d705c06fa91336e785d0a4e9b74849c2c974ce4bd97)], [uint256(0x0eb8eac18151b705bf3807564294a3d045c54c75bace6eed87ecf46938b6b784), uint256(0x2927675981f633c7d67615428cfcc61e57e5fa28b5acb8e5bcd84c6793781943)]);
+        vk.delta = Pairing.G2Point([uint256(0x2a6760500f782d36755385fc69a53b9ab2525c5e89ff6286dd24c3a63ce0dd07), uint256(0x066ec034e6a80570bef2bc52e1c51c5ce7e6f209aece1706bff4ed292ab4cda4)], [uint256(0x01d72bc0ccbde044acbba5671993915b3fb1c3de4336889ff7f01e8d6e1665bf), uint256(0x0ba4520de5ebb244f9c506ddabbed23cfe55eeb94c65b5f8d972f05c9c477d98)]);
+        vk.gamma_abc = new Pairing.G1Point[](2);
+        vk.gamma_abc[0] = Pairing.G1Point(uint256(0x010016ba1669d26675c2e71e7cb94d1d57829b45d6bf29ba599f9edd35a98ded), uint256(0x162f6bcb6186977ac3c6b39c5bc5feaf24ce1880b8812b96ec56642787df2d36));
+        vk.gamma_abc[1] = Pairing.G1Point(uint256(0x1dce208bca651bbe8d0dc37ac03cf6d6d687307b042d16945b201f3d419f1b54), uint256(0x048fc4938dc7f9707fdc6bf7619087248ae3b6f323df67601424c85d2fc90d48));
+    }
+    function verify(uint[] memory input, Proof memory proof) internal view returns (uint) {
+        uint256 snark_scalar_field = 21888242871839275222246405745257275088548364400416034343698204186575808495617;
+        VerifyingKey memory vk = verifyingKey();
+        require(input.length + 1 == vk.gamma_abc.length);
+        // Compute the linear combination vk_x
+        Pairing.G1Point memory vk_x = Pairing.G1Point(0, 0);
+        for (uint i = 0; i < input.length; i++) {
+            require(input[i] < snark_scalar_field);
+            vk_x = Pairing.addition(vk_x, Pairing.scalar_mul(vk.gamma_abc[i + 1], input[i]));
+        }
+        vk_x = Pairing.addition(vk_x, vk.gamma_abc[0]);
+        if(!Pairing.pairingProd4(
+             proof.a, proof.b,
+             Pairing.negate(vk_x), vk.gamma,
+             Pairing.negate(proof.c), vk.delta,
+             Pairing.negate(vk.alpha), vk.beta)) return 1;
+        return 0;
+    }
+    function verifyTx(
+            Proof memory proof, uint[1] memory input
+        ) public view returns (bool r) {
+        uint[] memory inputValues = new uint[](1);
+
+        for(uint i = 0; i < input.length; i++){
+            inputValues[i] = input[i];
+        }
+        if (verify(inputValues, proof) == 0) {
+            return true;
+        } else {
+            return false;
+        }
+    }
+}

election-scripts/__mocks__.ts

@@ -7,9 +7,9 @@ export const DECsRegistryData = {
 };
 
 export const VoterEOA = {
-  address: "0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266",
+  address: "0xdD2FD4581271e230360230F9337D5c0430Bf44C0",
   privateKey:
-    "0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80",
+    "0xde9be858da4a475276426320d5e9262ecfc3ba460bfac56360bfa6c4c28b4ee0",
 };
 
 export const DECMock = {
@@ -20,7 +20,7 @@ export const DECMock = {
 };
 
 export const MUNICIPALITY_ELECTION_DATA = {
-  name: "Election of major of Braccagni city",
+  name: "Election of mayor of Braccagni city",
   municipality: "Braccagni",
   region: "Toscana",
   country: "Italy",
@@ -29,10 +29,10 @@ export const MUNICIPALITY_ELECTION_DATA = {
   votingPoints: 20,
 };
 
-export const PARTY_NAME_A = "Partito Democratico";
-export const PARTY_NAME_B = "Forza Italia";
-export const PARTY_NAME_C = "Cinque Stelle";
-export const PARTY_NAME_D = "Lega";
+export const PARTY_NAME_A = "partitoDemocratico";
+export const PARTY_NAME_B = "cinqueStelle";
+export const PARTY_NAME_C = "forzaItalia";
+export const PARTY_NAME_D = "lega";
 
 export const MAJOR_CANDIDATE_1 = "Pino Pini";
 export const MAJOR_CANDIDATE_2 = "Ugo Silenti";

election-scripts/create-dec.test.ts

@@ -1,22 +1,24 @@
-import { assert } from "chai";
+import { expect } from "chai";
 import { main } from "./create-dec";
 import { Response, result, CreateDECResponse } from "../election-scripts/types";
 import { DECMock, VoterEOA } from "./__mocks__";
 
+jest.setTimeout(20000);
+
 describe("Create DEC Script", () => {
   it("Should run without errors", async () => {
     const response: Response<CreateDECResponse> = await main(
       DECMock,
       VoterEOA.privateKey,
     );
-    assert.equal(response.result, result.OK);
+    expect(response.result).to.equal(result.OK);
   });
 
   it("Should encrypt and deploy DEC correctly", async () => {
     const response: Response<CreateDECResponse> = await main(
       DECMock,
       VoterEOA.privateKey,
     );
-    assert.equal(response.result, result.OK);
+    expect(response.result).to.equal(result.OK);
   });
 });

election-scripts/create-decs-registry.test.ts

@@ -1,10 +1,10 @@
-import { assert } from "chai";
+import { expect } from "chai";
 import { main } from "./create-decs-registry";
 import { RegistryResponse, Response, result } from "../election-scripts/types";
 
 describe("Create DECs Registry Script", () => {
   it("Should run without errors", async () => {
     const response: Response<RegistryResponse> = await main();
-    assert.equal(response.result, result.OK);
+    expect(response.result).to.equal(result.OK);
   });
 });

election-scripts/create-decs-registry.ts

@@ -33,7 +33,7 @@ export async function main(): Promise<Response<RegistryResponse>> {
       DECsRegistryData.name,
     );
 
-    const contractName = await contract.getName();
+    const contractName = await contract.name;
 
     console.log(
       `The contract "${contractName}" has been successfully deployed`,