Get ethereum address from secpk256 public key not generated using geth crypto package

Question

I have a public key that gets generated using the secpk256 curve, I am trying to determine the ethereum address of this public key. Basically I obtain the key as a simple string and then try to use geths crypto functions to get the public address of this public key.

Heres a sample hex encoded public key string: 02ccb8bc17397c55242a27d1681bf48b5b40a734205760882cd83f92aca4f1cf45 heres my code sample:

package main

import (
    "github.com/ethereum/go-ethereum/crypto"
)


publickey := "02ccb8bc17397c55242a27d1681bf48b5b40a734205760882cd83f92aca4f1cf45"
ecdsaPub, err := crypto.UnmarshalPubkey(publickey)
if err != nil {
    return "", err
}
ethAddress := crypto.PubkeyToAddress(*ecdsaPub).String()

Answer 1

you should DecompressPubkey

package main

import (
    "crypto/elliptic"
    "encoding/hex"
    "fmt"
    "github.com/ethereum/go-ethereum/crypto"
    "github.com/ethereum/go-ethereum/crypto/secp256k1"
)


func main() {

    pubBytes, err := hex.DecodeString("03bbba49a934014049d99a7f5c809fd0da59b1cb47dcbd0b3fe097adc5eaa5ec42")
    if err != nil {
        fmt.Println(err, "--1")
    }
    if pubkey1, err := crypto.DecompressPubkey(pubBytes); err != nil {
        fmt.Println(err)
        return
    } else {
        pubkey := elliptic.Marshal(secp256k1.S256(), pubkey1.X, pubkey1.Y)
        fmt.Println(hex.EncodeToString(pubkey))
        //output :04bbba49a934014049d99a7f5c809fd0da59b1cb47dcbd0b3fe097adc5eaa5ec424b3e22bae2d8f20d4bf8c0c85ec1efbce4b91196962199cd743dd6f72433559f
    }

}