1

Note: I updated the html / JavaScript code according to the answer and I used THIS META MASK sample code for web3 provider. However, I receive the same error. I eventually did not understand that do I need run testRPC or not ?.

I run following html JavaScript code to generate a signature after running testRPC and using Meta Mask as follows:

(1) run testRPC :

PS C:\Users\s> testrpc
EthereumJS TestRPC v6.0.3 (ganache-core: 2.0.2

Available Accounts
==================
(0) 0xf4d2b942c3baebef5b81f4b909904015166b238a
(1) 0xef0d1e102d33252f232b39b31950f736ab2535aa
(2) 0x23064a138dc6b681a51a18b837a376f061fbc511
(3) 0x2dfaf5c48bc3c868f63741d6cd0489b336e74b03
(4) 0x372110011158860806d9d9b19aa67c045740727a
(5) 0x3faa74be50e1dfa86e5f6951a8c11b3e726edf65
(6) 0xaecc4c8f0b802b83a2cd84e6c98ecad6b0495c00
(7) 0x36b08ae47ec94870b98b0e0d98fca2646332ae87
(8) 0x1461cfb91f6fd2aca8d722dce9f67f7806732e49
(9) 0x1a0b2fd11e57f6473ae5f9b55e17cbfb6d8b504e

Private Keys
==================
(0) acb8b8ee76ce99fc390127ae88e246d3f8d8ac3db7
(1) 8957622705ccec21da4791f8535c70ab4726bfbe08
(2) 41181e3cf8c0294e949062a894bd96aea15e342db5
(3) c1bad63470c62b56032b034df0f0b827779e678cfd
(4) f49109620e9e56aa0bff9bdeb486d05ca75732cf1a
(5) ed1107372972a702c166924846f6d01234b9d277a7
(6) 10afce272e6a3d1d3474c385bf28be7e58de991995
(7) 0a92c9aa01497d29f01023cdeb50429954be06c949
(8) 87d0c56f9cab4c86ebc66749d0894719b647f72cea
(9) c8ca68e445b249a7d860fc3d76b210d6dd1a1c2197

HD Wallet
==================
Mnemonic:      access invest retire civil eagl
Base HD Path:  m/44'/60'/0'/0/{account_index}

(2) selecting 0xf4d2b942c3baebef5b81f4b909904015166b238a as signer address.

(3) adding 0xf4d2b942c3baebef5b81f4b909904015166b238a to Meta Mask.

(4) running following html / JavaScript code in Google Chrome :

<!doctype html>

<html lang="en">
<head>
  <meta charset="utf-8">
  <title>EthereumJS - Browser Example</title>
</head>

<body>
  <script src="https://rawgit.com/ethereumjs/browser-builds/master/dist/ethereumjs-abi/ethereumjs-abi-0.6.5.js"></script> 
  <script src="https://rawgit.com/ethereum/web3.js/develop/dist/web3.js"></script> 
  <script src="https://cdn.jsdelivr.net/gh/ethereum/web3.js/dist/web3.min.js"></script>

  <script>

window.addEventListener('load', function() {

   // Checking if Web3 has been injected by the browser (Mist/MetaMask)
  if (typeof web3 !== 'undefined') {
    // Use Mist/MetaMask's provider
    web3 = new Web3(web3.currentProvider);
  } else {
    console.log('No web3? You should consider trying MetaMask!')
    // fallback - use your fallback strategy (local node / hosted node + in-dapp id mgmt / fail)
    web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
  }

//  var Web3 
//  web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));

  function constructPaymentMessage(contractAddress, amount) 
  {
  return ethereumjs.ABI.soliditySHA3(
    ["address", "uint256"],
    [contractAddress, amount],
  );
  }

  var message = constructPaymentMessage("0x0f0f422477d83bcbed227b0ae2fa3ace7ea3c653", 100);
  console.log(message);

  web3.personal.sign("0x" + message.toString("hex"), "0xF4D2B942c3baebef5B81F4B909904015166b238A", function(err, signature) {
  console.log(signature);
  console.log(err);
  // Be sure to make use of the signature only here.
  // It will not be defined until this callback is invoked.
});

}) 
  </script>
</body>
</html>

And the following is the result :

enter image description here

Pleas note that

Uint8Array(32) [2, 16, 48, 216, 191, 103, 173, 178, 132, 121, 144, 241, 45, 224, 83, 239, 76, 206, 69, 151, 42, 86, 174, 144, 3, 97, 172, 171, 166, 231, 234, 10]

is the message value and result of console.log(message); and not signature value and when I use console.log(signature); the output is only undefined.

How can I see signature value ?

And the following is the error message, result of console.log(err); :

Error: Method personal_sign not supported

Error: Error: Method personal_sign not supported.
    at GethApiDouble.handleRequest (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:89858:16)
    at next (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:59378:18)
    at GethDefaults.handleRequest (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:89767:12)
    at next (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:59378:18)
    at FilterSubprovider.handleRequest (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:65832:7)
    at next (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:59378:18)
    at DelayedBlockFilter.handleRequest (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:89595:3)
    at next (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:59378:18)
    at ReactiveBlockTracker.handleRequest (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:89722:12)
    at next (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:59378:18)
    at GethApiDouble.handleRequest (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:89858:16)
    at next (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:59378:18)
    at GethDefaults.handleRequest (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:89767:12)
    at next (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:59378:18)
    at FilterSubprovider.handleRequest (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:65832:7)
    at next (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:59378:18)
    at DelayedBlockFilter.handleRequest (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:89595:3)
    at next (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:59378:18)
    at ReactiveBlockTracker.handleRequest (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:89722:12)
    at next (C:\Users\s\AppData\Roaming\npm\node_modules\ethereumjs-testrpc\build\cli.node.js:59378:18)
    at Object.InvalidResponse (https://rawgit.com/ethereum/web3.js/develop/dist/web3.js:3138:16)
    at https://rawgit.com/ethereum/web3.js/develop/dist/web3.js:6375:36
    at XMLHttpRequest.request.onreadystatechange (https://rawgit.com/ethereum/web3.js/develop/dist/web3.js:4377:7)

Related question: "UPDATED : " "VM Exception while processing transaction: revert"

Improve this question
7
  • 1
    There is no reason to include "web3.js" and "web3.min.js". They are the same thing.
    – Shawn Tabrizi
    Jul 22, 2018 at 20:08
  • @Shawn Tabrizi Do you mean I can remove one of them ? Thanks
    – Questioner
    Jul 22, 2018 at 20:10
  • 1
    Yes. You should probably only be using the web3.min.js file unless you want to look at the source code. See Minification (programming)
    – Shawn Tabrizi
    Jul 22, 2018 at 20:12
  • @Shawn Tabrizi According to comment of smarx I need to add MetaMast web3 provider in the code. Does it mean I need to replace HttpProvider("http://localhost:8545")) by something else ? Thanks
    – Questioner
    Jul 22, 2018 at 20:22
  • 1
    window.web3 = new Web3(web3.currentProvider); Check out my answer to your other question
    – Shawn Tabrizi
    Jul 22, 2018 at 20:30

1 Answer 1

Reset to default
1

The signature is sent to your callback, which is empty in the code you shared. This should work:

web3.personal.sign("0x" + message.toString("hex"), "0xF4D2B942c3baebef5B81F4B909904015166b238A", function(err, signature) {
  console.log(signature);
  // Be sure to make use of the signature only here.
  // It will not be defined until this callback is invoked.
});

As an aside, note that your current code does not use MetaMask.

Improve this answer
22
  • 1
    Then try printing out the err.
    – user19510
    Jul 22, 2018 at 19:42
  • 2
    testrpc doesn't support the method personal_sign. You'll need to use geth, Parity, MetaMask, or something else that does support that method.
    – user19510
    Jul 22, 2018 at 20:04
  • 1
    Your code needs to use the MetaMask web3 provider. You're instead connecting directly to testrpc. And yes, of course you need to run testrpc for MetaMask to be able to connect to it.
    – user19510
    Jul 22, 2018 at 20:10
  • 1
    The MetaMask documentation will help.
    – user19510
    Jul 22, 2018 at 20:29
  • 1
    That message means you're not using MetaMask. (MetaMask didn't inject web3, so it was undefined.) If you're running your page from a file:// URL, then yes, this is the problem. You need to run from an http:// or https:// URL. Running locally is fine, but it needs to be via a web server, not the filesystem.
    – user19510
    Jul 22, 2018 at 23:52

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