2.1 Signing messages

.openzeppelin/goerli.json

@@ -288,6 +288,22 @@
         ],
         "storageDiff": []
       }
+    },
+    "Verifier": {
+      "address": "0xB735f8730debFF357593dba17a7Fa3dD783b3DAe",
+      "constructorCode": "608060405234801561001057600080fd5b506105e7806100206000396000f3fe",
+      "bodyBytecodeHash": "cdcbeb651e8382f67e592daa834afb098964fcd557a81f930da622eb8eef0c64",
+      "localBytecodeHash": "52180514532af933f2e70d0473a69942db0b6637089152e6560d45ec6eeb3e58",
+      "deployedBytecodeHash": "52180514532af933f2e70d0473a69942db0b6637089152e6560d45ec6eeb3e58",
+      "types": {},
+      "storage": [],
+      "warnings": {
+        "hasConstructor": false,
+        "hasSelfDestruct": false,
+        "hasDelegateCall": false,
+        "hasInitialValuesInDeclarations": false,
+        "uninitializedBaseContracts": []
+      }
     }
   },
   "solidityLibs": {},
@@ -307,6 +323,15 @@
         "admin": "0x5c19BF66CC2c9386Cdf06d346F32F140A4559be9",
         "kind": "Upgradeable"
       }
+    ],
+    "ledger-academy/Verifier": [
+      {
+        "address": "0xB0e0f956693eC1e990EB95C3a435B80548F7db1b",
+        "version": "1.0.0",
+        "implementation": "0xB735f8730debFF357593dba17a7Fa3dD783b3DAe",
+        "admin": "0x5c19BF66CC2c9386Cdf06d346F32F140A4559be9",
+        "kind": "Upgradeable"
+      }
     ]
   },
   "manifestVersion": "2.2",

.openzeppelin/project.json

@@ -1,7 +1,8 @@
 {
   "manifestVersion": "2.2",
   "contracts": {
-    "ADIToken": "ADIToken"
+    "ADIToken": "ADIToken",
+    "Verifier": "Verifier"
   },
   "dependencies": {
     "@openzeppelin/contracts-ethereum-package": "^3.0.0"

contracts/Verifier.json

@@ -0,0 +1 @@
+../build/contracts/Verifier.json

contracts/Verifier.sol

@@ -0,0 +1,23 @@
+pragma solidity ^0.6.0;
+
+import  "@openzeppelin/contracts-ethereum-package/contracts/cryptography/ECDSA.sol";
+
+// https://www.codementor.io/@yosriady/signing-and-verifying-ethereum-signatures-vhe8ro3h6
+// -> part of oz: https://docs.openzeppelin.com/contracts/3.x/api/cryptography#ECDSA-recover-bytes32-bytes-
+
+contract Verifier {
+    function recoverAddr(
+        bytes32 msgHash,
+        bytes memory signature
+    ) public pure returns (address) {
+        return ECDSA.recover(msgHash, signature);
+    }
+
+    function recoverAddrFromNonEthHash(
+        bytes32 msgHash,
+        bytes memory signature
+    ) public pure returns (address) {
+        bytes32 ethHash = ECDSA.toEthSignedMessageHash(msgHash);
+        return recoverAddr(ethHash, signature);
+    }
+}

src/Main.tsx

@@ -5,6 +5,8 @@ import Web3 from "web3";
 import ADIToken from "./contracts/ADIToken.json";
 import TransferForm from "./TransferForm";
 import _secrets from "../.secrets.json";
+import SignForm from "./SignForm";
+import VerifyForm from "./VerifyForm";
 
 const Main: React.FC = () => {
   const { account, library: web3 } = useWeb3React<Web3>();
@@ -36,7 +38,6 @@ const Main: React.FC = () => {
         const readableAdiBalance = Web3.utils.fromWei(_adiBalance);
         setADIBalance(readableAdiBalance);
       }
-
     })();
   }, [web3]);
 
@@ -53,9 +54,15 @@ const Main: React.FC = () => {
         <small>({_secrets.contractAddress})</small>
       </p>
       <p>to spare with others.</p>
+
+      <h2>Transfer ADI</h2>
       {adiBalance && (
         <TransferForm updateBalance={queryADIBalance}></TransferForm>
       )}
+      <h2>Sign a message</h2>
+      <SignForm /> <br/>
+      <h2>Verify a message</h2>
+      <VerifyForm /> <br/>
     </div>
   );
 };

src/SignForm.tsx

@@ -0,0 +1,37 @@
+import React, { useState } from "react";
+import { useWeb3React } from "@web3-react/core";
+import Web3 from "web3";
+
+const SignForm = () => {
+  const { account, library: web3 } = useWeb3React<Web3>();
+  const [message, setMessage] = useState<string>("");
+
+  const [signature, setSignature] = useState<string>("");
+
+  async function signMessage() {
+    const signed = await web3.eth.personal.sign(message, account, "")
+    setSignature(signed);
+  }
+
+  return (
+    <div>
+          <label htmlFor="address">Message</label>
+          <input
+            type="text"
+            value={message}
+            onChange={(e) => setMessage(e.target.value)}
+          />
+
+          <button disabled={!message} onClick={signMessage}>
+            Sign!
+          </button>
+          <br />
+          {signature && 
+          <small><b>Signature: {signature}</b></small>
+          }
+
+    </div>
+  );
+};
+
+export default SignForm;

src/VerifyForm.tsx

@@ -0,0 +1,104 @@
+import React, { useState } from "react";
+import { useWeb3React } from "@web3-react/core";
+import Web3 from "web3";
+import VerifierABI  from "./contracts/Verifier.json";
+
+import _secrets from "../.secrets.json";
+
+const VerifyForm = () => {
+  const { library: web3, account } = useWeb3React<Web3>();
+  const [message, setMessage] = useState<string>("");
+  const [signature, setSignature] = useState<string>("");
+  const [localVerificationResult, setLocalVerificationResult] = useState<string>("");
+  const [contractVerificationResult, setContractVerificationResult] = useState<string>("");
+  const [nonEthSignatureVerificationResult, setNonEthSignatureVerificationResult] = useState<string>("");
+
+  const contract = new web3.eth.Contract(
+    VerifierABI.abi,
+    _secrets.verifierContractAddress
+  );
+
+  // this will only work with messages that have been a hash by itself ;)
+  async function verifyNonEthSignatureOnContract() {
+    const nonEthMessageHash = web3.utils.sha3(message); 
+    const recovered = await contract.methods.recoverAddrFromNonEthHash(
+      nonEthMessageHash,
+      signature
+    ).call()
+
+    console.log(recovered);
+    setNonEthSignatureVerificationResult(recovered);
+  }
+
+  async function verifySignatureOnContract() {
+    const verifiableMessage = `\x19Ethereum Signed Message:\n${message.length}${message}`;
+    const verifiableMessageSha = web3.utils.sha3(verifiableMessage); 
+
+    const recovered = await contract.methods.recoverAddr(
+      verifiableMessageSha,
+      signature
+    ).call()
+
+    console.log(recovered);
+    setContractVerificationResult(recovered);
+  }
+
+  async function verifySignatureLocally() {
+    const recovered = await web3.eth.personal.ecRecover(message, signature);
+    console.log(recovered);
+    setLocalVerificationResult(web3.utils.toChecksumAddress(recovered));
+  }
+
+  async function verifySignature() {
+    verifySignatureLocally();
+    verifySignatureOnContract();
+    verifyNonEthSignatureOnContract();
+  }
+
+  function eqAccount(addr: string) {
+    return addr === account
+  }
+  return (
+    <div>
+      <label>Message</label>
+      <input
+        type="text"
+        value={message}
+        onChange={(e) => setMessage(e.target.value)}
+      />
+
+      <label>Signature</label>
+      <input
+        type="text"
+        value={signature}
+        onChange={(e) => setSignature(e.target.value)}
+      />
+
+      <button disabled={!message} onClick={verifySignature}>
+        Verify!
+      </button>
+
+      <br />
+
+      { localVerificationResult && 
+        <small style={{color: eqAccount(localVerificationResult) ? 'green':'red'}}>
+          local verification: {localVerificationResult}
+          <br />
+        </small>
+      }
+      { contractVerificationResult && 
+        <small style={{color: eqAccount(contractVerificationResult) ? 'green':'red'}}>
+          contract verification: {contractVerificationResult} <br />
+        </small>
+      }
+      { nonEthSignatureVerificationResult && 
+        <small style={{color: eqAccount(nonEthSignatureVerificationResult) ? 'green':'red'}}>
+          non eth signed verification: {nonEthSignatureVerificationResult}
+        </small>
+      }
+
+    </div>
+  );
+};
+
+export default VerifyForm;

src/contracts/Verifier.json

@@ -0,0 +1 @@
+../../build/contracts/Verifier.json