code: func DERToPublicKey(raw []byte) (pub interface{}, err error) {
  	if len(raw) == 0 {
  		return nil, errors.New("Invalid DER. It must be different from nil.")
  	}
  
  	key, err := x509.ParsePKIXPublicKey(raw)
  
  	return key, err
  }
docs: // DERToPublicKey unmarshals a der to public key