Generation

        Indicates whether the password was chosen by the
        Principal or auto-supplied by the Authentication Authority.
        principalchosen - the Principal is allowed to choose
        the value of the password. This is true even if
        the initial password is chosen at random by the UA or
        the IdP and the Principal is then free to change
        the password.
        automatic - the password is chosen by the UA or the
        IdP to be cryptographically strong in some sense,
        or to satisfy certain password rules, and that the
        Principal is not free to change it or to choose a new password.