On Wed, Feb 28, 2018 at 1:01 AM, Amarjeet Singh <[email protected]>
wrote:

> Hi Team,
>
> I am working on enabling and disabling clipboard.
>
> I went through *FreeRDP Manual* from which I found  the following  variable
> in rdpSettings structure which is as follows:-
>

As far as disabling clipboard access within Guacamole is concerned, simply
requesting FreeRDP to not use clipboard would be the RDP version of
genetically engineering your dinosaurs to be female. You should instead
absolutely guarantee that clipboard will not function by controlling things
at the Guacamole protocol level, ignoring received clipboard data from the
client (by not providing a handler for that data), and not forwarding
clipboard data to the client even if received from the RDP server.

Recall that, for clipboard data to be received/sent by the client, a
"clipboard" instruction is used to establish the stream of data:

http://guacamole.apache.org/doc/gug/protocol-reference.html#clipboard-instruction

To ensure this does not actually have an effect, you would want to make
handling of that instruction conditional depending on some enable/disable
flag, and disable sending of clipboard data to connected clients while that
flag is sent. Conditional handling of instructions is already used for
implementing the "read-only" parameter, and is really what would be
required here:

https://github.com/apache/guacamole-server/blob/bc5b01d4d8ab0c3c89a08007316d33012261f6b3/src/protocols/rdp/user.c#L97-L114

Besides being reliable, this has the added bonus that the fact that
clipboard streams cannot be established is automatically exposed to the
client through "ack" instructions, and implementations can choose to handle
this by adjusting the interface accordingly, warning the user that
clipboard has been disabled, etc.

- Mike

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