Ethereum - Sign arbitrary data (sign cosmos tx bytes)

eth-sign.js

var Web3 = require('web3');
var web3 = new Web3(window.web3.currentProvider);

var accountToSignWith = '0xbedcf417ff2752d996d2ade98b97a6f0bef4beb9';
var message = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Tubulum fuisse, qua illum, cuius is condemnatus est rogatione, P. Eaedem res maneant alio modo.'

function signHandler(err, signature) {
	if (!err) {
		console.log('Signature:', signature);
		signature = signature.substr(2);
		r = '0x' + signature.substr(0, 64);
		s = '0x' + signature.substr(64, 64);
		v = '0x' + signature.substr(128, 2)
				
		console.log('        r:', r)
		console.log('        s:', s)
		console.log('        v:', v)
	} else {
		console.error('Coult not sign message:', err);
	}
}

function ascii_to_hex(str)
{
	var arr1 = [];
	for (var n = 0, l = str.length; n < l; n ++) 
     	{
		var hex = Number(str.charCodeAt(n)).toString(16);
		arr1.push(hex);
	 }
	return arr1.join('');
}

console.log('Message to sign:', message);
console.log('Sign with account:', accountToSignWith);
var messageHex = '0x' + ascii_to_hex(message);
// var messageHex = '0x' + keccak256(signDocBytes); // cosmos chain 

window.ethereum.enable().then(function() {
    web3.eth.sign(messageHex, accountToSignWith, signHandler);
});