signature=049bc13d9571d1c0224997c83ec25925,go - Geth ecrecover invalid signature recovery id - Stack...

I'm trying to verify signature passed in from client using the geth golang library. I'm getting the sample data (signature / address) from one of my cryptokitties accounts (I can see it in the request). If I paste the blow credentials into https://etherscan.io/verifySig, it gets verified, so I know the parameters are correct.

My code:

import (

"github.com/ethereum/go-ethereum/common/hexutil"

"github.com/ethereum/go-ethereum/crypto"

)

sig := 0x80f5bac5b6300ed64835d5e2f167a368c892ccc2d0e252bc84befbcb093f5a2d36294b95d86683cec778c8c796049933c04c71576c56c1d6e9a9fa10342beca31c

data := "Cryptokitties"

decoded = hexutil.MustDecode(sig) // j8aUTtPid0ZnNa/s4Ef5gisYYh1bCeLSmFrtJtDjNRRqxShUr+1A3BVgoAPwiZ+lKN0POB1JOdVhVHI9tcHmABs=

hash := crypto.Keccak256([]byte(data)) // "ljQQTm25oqIbD+LMl70aRUcTzXCeeDGfkRj9YJYsgKY="

pubKey, err := crypto.Ecrecover(hash, sig) // error: "invalid signature recovery id"

I'm sure I'm missing something simple, but not really sure where to look.

**UPDATE

What I tried after looking around some answers:

changing the message like this:

fmt.Sprintf("u0019Ethereum Signed Message:n%d%s", len(data), data) //"u0019Ethereum Signed Message:n13Cryptokitties"

hex encoding the message before hashing it:

data=hexutil.Encode(data)

combining the above two, so first prepending the 'Ethereum Signed Message', then hexencoding it.

Any points would be appreciated, I'm sure this is a noob question.

**UPDATE

Looking through the source code, I discovered its expecting recovery id to be greater than 4:

sig[64] >= 4

In my case it turns out to be 27:

sig[64] --> 27