eth_sign_verify.go

works like a charm

This is godsend!

Saved me from more head-breaking. Thank you!

Thank you. geth should use this as an example

4 years later this is saving lives.

Worked. Thanks man!

Hello internet. Make sure to read the latest version of func (s *PrivateAccountAPI) EcRecover at https://github.com/ethereum/go-ethereum/blob/master/internal/ethapi/api.go.
Notable changes are:

• The 64 is replaced with crypto.RecoveryIDOffset
• signHash is replaced with accounts.TextHash

Maybe @dcb9 should update this gist.

it works, really thanks

simplified version

package main

import (
	"fmt"

	"github.com/ethereum/go-ethereum/accounts"
	"github.com/ethereum/go-ethereum/common/hexutil"
	"github.com/ethereum/go-ethereum/crypto"
)

func main() {
	fmt.Println(verifySig(
		"0x0EaE3eF6CC7176553E6B45d94e9eFDE2Da7B82a5",
		"0x34850b7e36e635783df0563c7202c3ac776df59db5015d2b6f0add33955bb5c43ce35efb5ce695a243bc4c5dc4298db40cd765f3ea5612d2d57da1e4933b2f201b",
		[]byte("Example `personal_sign` message"),
	))
}

func verifySig(from, sigHex string, msg []byte) bool {
	sig := hexutil.MustDecode(sigHex)

	msg = accounts.TextHash(msg)
	sig[crypto.RecoveryIDOffset] -= 27 // Transform yellow paper V from 27/28 to 0/1

	recovered, err := crypto.SigToPub(msg, sig)
	if err != nil {
		return false
	}

	recoveredAddr := crypto.PubkeyToAddress(*recovered)

	return from == recoveredAddr.Hex()
}

Author

@krasi-georgiev Perfect I copied yours as the latest version
@rht Thanks you so much

It works! Thanks!

Good! helped me a lot!

Do you have any examples on generating the signature?

Helped a lot cheers !

Works fine but I need to replace

	sig[crypto.RecoveryIDOffset] -= 27 // Transform yellow paper V from 27/28 to 0/1

	if sig[crypto.RecoveryIDOffset] == 27 || sig[crypto.RecoveryIDOffset] == 28 {
		sig[crypto.RecoveryIDOffset] -= 27 // Transform yellow paper V from 27/28 to 0/1
	}

Amazing! Worked on the first go!