fix signature

src/blockchain/providers/injected.js

 const Web3 = require('web3')
-const { stripHexPrefix } = require('ethereumjs-util')
+const { stripHexPrefix, hashPersonalMessage } = require('ethereumjs-util')
 
 class InjectedProvider {
 
@@ -35,10 +35,10 @@ class InjectedProvider {
   }
 
   signMessage (message, account, _passphrase, cb) {
-    const hashedMsg = Web3.utils.sha3(message)
+    const messageHash = hashPersonalMessage(Buffer.from(message))
     try {
-      this.executionContext.web3().eth.sign(hashedMsg, account, (error, signedData) => {
-        cb(error, hashedMsg, signedData)
+      this.executionContext.web3().eth.sign(message, account, (error, signedData) => {
+        cb(error, '0x' + messageHash.toString('hex'), signedData)
       })
     } catch (e) {
       cb(e.message)

src/blockchain/providers/node.js

 const Web3 = require('web3')
-const { stripHexPrefix } = require('ethereumjs-util')
+const { stripHexPrefix, hashPersonalMessage } = require('ethereumjs-util')
 const Personal = require('web3-eth-personal')
 
 class NodeProvider {
@@ -43,11 +43,11 @@ class NodeProvider {
   }
 
   signMessage (message, account, passphrase, cb) {
-    const hashedMsg = Web3.utils.sha3(message)
+    const messageHash = hashPersonalMessage(Buffer.from(message))
     try {
       const personal = new Personal(this.executionContext.web3().currentProvider)
-      personal.sign(hashedMsg, account, passphrase, (error, signedData) => {
-        cb(error, hashedMsg, signedData)
+      personal.sign(message, account, passphrase, (error, signedData) => {
+        cb(error, '0x' + messageHash.toString('hex'), signedData)
       })
     } catch (e) {
       cb(e.message)

src/blockchain/providers/vm.js

 const Web3 = require('web3')
-const { BN, privateToAddress, stripHexPrefix } = require('ethereumjs-util')
+const { BN, privateToAddress, stripHexPrefix, hashPersonalMessage } = require('ethereumjs-util')
 const RemixSimulator = require('remix-simulator')
 
 class VMProvider {
@@ -54,12 +54,12 @@ class VMProvider {
   }
 
   signMessage (message, account, _passphrase, cb) {
-    const hashedMsg = Web3.utils.sha3(message)
-    this.web3.eth.sign(hashedMsg, account, (error, signedData) => {
+    const messageHash = hashPersonalMessage(Buffer.from(message))
+    this.web3.eth.sign(message, account, (error, signedData) => {
       if (error) {
         return cb(error)
       }
-      cb(null, hashedMsg, signedData)
+      cb(null, '0x' + messageHash.toString('hex'), signedData)
     })
   }