verify from RPC

[bit-warrior]

Why is this block not verifying using ethhash

var Promise= require('bluebird');
var Web3 = require('web3');
var web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
const ethUtil = require('ethereumjs-util')
const Ethash = require('ethashjs')
const Block = require('ethereumjs-block')
const levelup = require('levelup')
const memdown = require('memdown')
const rlp = require('rlp')
const fromrpc=require('./from-rpc.js')
var cacheDB = levelup('', {
  db: memdown
})


var ethash = new Ethash(cacheDB);

  web3.eth.getBlock(220).then(function(data) {

		  	console.log(data)

		        var validblock = new fromrpc(data)
		ethash.verifyPOW(validblock, function (result) {
		  console.log(result)
		})
});

[holgerd77]

Hi, I'm not the maintainer of this library, but had a short look into this and can confirm that PoW mixHash is not verified within this example, not sure about the reason though.

Here is a modified code snippet of the example above which can be run directly from this library for further debugging:

var Promise= require('bluebird')
var Web3 = require('web3')
var web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"))
const ethUtil = require('ethereumjs-util')
const Ethash = require('./index.js')
const Block = require('ethereumjs-block')
const levelup = require('levelup')
const memdown = require('memdown')
const rlp = require('rlp')
const fromrpc = require('ethereumjs-block/from-rpc.js')
var cacheDB = levelup('', {
  db: memdown
})


var ethash = new Ethash(cacheDB)

web3.eth.getBlock(220).then(function(data) { 
  var validBlock = new fromrpc(data)
  console.log(data)
  ethash.verifyPOW(validBlock, function (result) {
    console.log(result)
  })
})

Testing requires a running geth node (or other), e.g. with (after having synced to block 220):

geth --rpc --syncmode="full" --maxpeers=0

Also these libraries have to be installed manually:

npm install bluebird --no-save
npm install web3 --no-save

Verification already fails when trying to verify the main block header (not the uncles), on this comparison both boolean values are evaluated as false.