def changePassword(user, oldpswd, newpswd):
    """
    This function allows to change the user password on the KDC.

    @param user: A string containing the Kerberos user name.
        A realm may be included by appending a C{"@"} followed by the realm
        string to the actual user id.
        If no realm is supplied, then the realm set in the default_realm
        argument will be used.

    @param oldpswd: A string containing the old (current) password for the
        user.

    @param newpswd: A string containing the new password for the user.

    @return: True if password changing succeeds, false otherwise.
    """
