Develop

contracts/DEC.sol

@@ -6,12 +6,13 @@ pragma solidity ^0.8.24;
 /// @custom:experimental This is an experimental contract.
 contract DEC {
     address public owner;
-    Encrypted taxCode;
-    Encrypted municipality;
-    Encrypted region;
-    Encrypted country;
+    Encrypted public taxCode;
+    Encrypted public municipality;
+    Encrypted public region;
+    Encrypted public country;
 
     struct Encrypted {
+        string sha;
         string chiper;
         string nonce;
     }
@@ -39,33 +40,15 @@ contract DEC {
         taxCode = _taxCode;
     }
 
-    function getTaxCode() external view returns (Encrypted memory) {
-        return taxCode;
-    }
-
     function setMunicipality(Encrypted memory _municipality) external onlyOwner {
         municipality = _municipality;
     }
 
-    function getMunicipality() external view returns (Encrypted memory) {
-        return municipality;
-    }
-
     function setRegion(Encrypted memory _region) external onlyOwner {
         region = _region;
     }
 
-    function getRegion() external view returns (Encrypted memory) {
-        return region;
-    }
-
     function setCountry(Encrypted memory _country) external onlyOwner {
         country = _country;
     }
-
-    function getCountry() external view returns (Encrypted memory) {
-        return country;
-    }
-
-
 }

lib/crypto-utils.test.ts

@@ -1,4 +1,4 @@
-import { encryptString, decryptString } from "./crypto-utils";
+import { encryptString, decryptString, getHash } from "./crypto-utils";
 import { mockEOAs } from "./__mocks__";
 
 describe("Crypto Utils", () => {
@@ -30,4 +30,14 @@ describe("Crypto Utils", () => {
       expect(e.message).toBe("Error decrypting string");
     }
   });
+
+  it("should return a SHA hash for a given message", () => {
+    const message = "Hello, world!";
+    const expectedHash =
+      "f345a219da005ebe9c1a1eaad97bbf38a10c8473e41d0af7fb617caa0c6aa722";
+
+    const result = getHash(message);
+
+    expect(result).toEqual({ sha: expectedHash });
+  });
 });

lib/crypto-utils.ts

@@ -6,7 +6,7 @@
  * is because If we send the data and then encrypt it in solidity, the data will be visible in the transaction that
  * in the first place was used to send the data to the contract. Also, solidity doesn't have a function to encrypt.
  */
-import { Encrypted, Decrypted } from "./types";
+import { Encrypted, Decrypted, Sha } from "./types";
 import { execSync, ExecSyncOptionsWithStringEncoding } from "child_process";
 import * as path from "path";
 
@@ -40,6 +40,7 @@ export function encryptString(
     );
 
     const response: Encrypted = JSON.parse(encrypted.toString());
+    response.sha = getHash(decryptedString).sha;
 
     return response;
   } catch (e) {
@@ -84,6 +85,26 @@ export function decryptString(
   }
 }
 
+export function getHash(message: string): Sha {
+  try {
+    const execSyncOptions = {
+      stdio: "pipe",
+    } as ExecSyncOptionsWithStringEncoding;
+
+    const cryptoPyPath = getCryptoPyPath();
+    const hashed = execSync(
+      `cd ${cryptoPyPath} && python3 Crypto.py sha3_256 --input="${message}"`,
+      execSyncOptions,
+    );
+
+    const response: Sha = JSON.parse(hashed.toString());
+
+    return response;
+  } catch (e: any) {
+    throw new Error("Error hashing the message");
+  }
+}
+
 /**
  * The crypto-py library should be manually copy-pasted (or git cloned) inside the lib folder.
  * Linux and MacOS users can in alternative create a symbolic link.

lib/types.ts

@@ -1,8 +1,13 @@
 export type Encrypted = {
+  sha: string;
   chiper: string;
   nonce: string;
 };
 
 export type Decrypted = {
   message: string;
 };
+
+export type Sha = {
+  sha: string;
+};

package.json

@@ -1,6 +1,6 @@
 {
   "name": "agora",
-  "version": "0.9.0",
+  "version": "0.10.0",
   "description": "A confidentiality-first electronic voting system",
   "author": {
     "name": "nova collective",

test/DEC.ts

@@ -10,10 +10,12 @@ describe("DEC Contract", () => {
   const encryptedDataFactory = function (
     chiper: string,
     nonce: string,
+    sha: string,
   ): Encrypted {
     return {
       chiper,
       nonce,
+      sha,
     };
   };
 
@@ -45,29 +47,33 @@ describe("DEC Contract", () => {
       await (await ethers.provider.getSigner(0)).getAddress(),
     );
 
-    const registeredTaxCode = await dec.getTaxCode();
-    const registeredMunicipality = await dec.getMunicipality();
-    const registeredRegion = await dec.getRegion();
-    const registeredCountry = await dec.getCountry();
+    const registeredTaxCode: Encrypted = await dec.taxCode();
+    const registeredMunicipality: Encrypted = await dec.municipality();
+    const registeredRegion: Encrypted = await dec.region();
+    const registeredCountry: Encrypted = await dec.country();
 
     const enTaxCode = encryptedDataFactory(
-      registeredTaxCode[0],
-      registeredTaxCode[1],
+      registeredTaxCode.chiper,
+      registeredTaxCode.nonce,
+      registeredTaxCode.sha,
     );
 
     const enMunicipality = encryptedDataFactory(
-      registeredMunicipality[0],
-      registeredMunicipality[1],
+      registeredMunicipality.chiper,
+      registeredMunicipality.nonce,
+      registeredMunicipality.sha,
     );
 
     const enRegion = encryptedDataFactory(
-      registeredRegion[0],
-      registeredRegion[1],
+      registeredRegion.chiper,
+      registeredRegion.nonce,
+      registeredRegion.sha,
     );
 
     const enCountry = encryptedDataFactory(
-      registeredCountry[0],
-      registeredCountry[1],
+      registeredCountry.chiper,
+      registeredCountry.nonce,
+      registeredCountry.sha,
     );
 
     const decodedTaxCode = decryptString(
@@ -100,21 +106,26 @@ describe("DEC Contract", () => {
   it("Should set and get tax code correctly", async () => {
     await dec.setTaxCode(eTaxCode);
 
-    const getTaxCode = await dec.getTaxCode();
+    const getTaxCode = await dec.taxCode();
 
-    const gTaxCode = encryptedDataFactory(getTaxCode[0], getTaxCode[1]);
+    const gTaxCode = encryptedDataFactory(
+      getTaxCode.chiper,
+      getTaxCode.nonce,
+      getTaxCode.sha,
+    );
 
     assert.equal(JSON.stringify(eTaxCode), JSON.stringify(gTaxCode));
   });
 
   it("Should set and get municipality correctly", async () => {
     await dec.setMunicipality(eMunicipality);
 
-    const getMunicipality = await dec.getMunicipality();
+    const getMunicipality = await dec.municipality();
 
     const gMunicipality = encryptedDataFactory(
-      getMunicipality[0],
-      getMunicipality[1],
+      getMunicipality.chiper,
+      getMunicipality.nonce,
+      getMunicipality.sha,
     );
 
     assert.equal(JSON.stringify(eMunicipality), JSON.stringify(gMunicipality));
@@ -123,19 +134,27 @@ describe("DEC Contract", () => {
   it("Should set and get region correctly", async () => {
     await dec.setRegion(eRegion);
 
-    const getRegion = await dec.getRegion();
+    const getRegion = await dec.region();
 
-    const gRegion = encryptedDataFactory(getRegion[0], getRegion[1]);
+    const gRegion = encryptedDataFactory(
+      getRegion.chiper,
+      getRegion.nonce,
+      getRegion.sha,
+    );
 
     assert.equal(JSON.stringify(eRegion), JSON.stringify(gRegion));
   });
 
   it("Should set and get country correctly", async () => {
     await dec.setCountry(eCountry);
 
-    const getCountry = await dec.getCountry();
+    const getCountry = await dec.country();
 
-    const gCountry = encryptedDataFactory(getCountry[0], getCountry[1]);
+    const gCountry = encryptedDataFactory(
+      getCountry.chiper,
+      getCountry.nonce,
+      getCountry.sha,
+    );
 
     assert.equal(JSON.stringify(eCountry), JSON.stringify(gCountry));
   });