* @param mechanism
     * @return whether the specified mechanism is supported
     */
    boolean isSupported ( ASN1ObjectIdentifier mechanism );


    /**
     * @param selectedMech
     * @return whether the specified mechanism is preferred
     */
    boolean isPreferredMech ( ASN1ObjectIdentifier selectedMech );


    /**
     * @return context flags
     */
    int getFlags ();


    /**