private function hashKey(string $value): string
    {
        $ret = openssl_digest($value, $this->digestMethod, true);
        if ($ret === false) {
            throw new \Exception("digest failed; ".openssl_error_string());
        }
        return $ret;
    }
private function hashKey(string $value): string
    {
        $ret = openssl_digest($value, $this->digestMethod, true);
        if ($ret === false) {
            throw new \Exception("digest failed; ".openssl_error_string());
        }
        return $ret;
    }
private function hashKey ( string $ value ) : string { $ ret = openssl_digest ( $ value , $ this -> digestMethod , true ) ; if ( $ ret === false ) { throw new \ Exception ( "digest failed; " . openssl_error_string ( ) ) ; } return $ ret ; }
Compute a digest hash for a value

@param string $value The value to hash
@return string
@throws \Exception If `openssl_digest` fails
Compute a digest hash for a value