package utils import ( "crypto/rsa" "crypto/x509" "encoding/pem" "errors" "io/ioutil" ) // LoadPrivateKeyFromFile loads a private key from a file... func LoadPrivateKeyFromFile(filename string) (*rsa.PrivateKey, error) { pemData, err := ioutil.ReadFile(filename) if err != nil { return nil, err } block, _ := pem.Decode(pemData) if block == nil || block.Type != "RSA PRIVATE KEY" { return nil, errors.New("not a private key") } return x509.ParsePKCS1PrivateKey(block.Bytes) }