[
https://issues.apache.org/jira/browse/GUACAMOLE-1717?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Mike Powers updated GUACAMOLE-1717:
-----------------------------------
Description:
When connecting to a [Gnome Remote
Desktop|https://gitlab.gnome.org/GNOME/gnome-remote-desktop] RDP instance the
mouse cursor is created but the image data is never copied into the cursor's
pixel buffer resulting in a garbled bitmap containing uninitialized data:
!image-2022-11-20-20-14-11-333.png|width=656,height=355!
This appears to happen because of this [guard
condition|https://github.com/apache/guacamole-server/blob/3ca6bb0a61715d17dc263e565e6ce0de7354606c/src/protocols/rdp/pointer.c#L50]
in src/protocols/rdp/pointer.c (line 49):
{code:java}
if (pointer->andMaskData && pointer->xorMaskData) {code}
It appears when Gnome Remote Desktop [initializes
cursors|https://gitlab.gnome.org/GNOME/gnome-remote-desktop/-/blob/master/src/grd-session-rdp.c#L591]
when starting the session it sets `andMaskData` to NULL with a length of zero:
pointer_color->lengthAndMask = 0; pointer_color->lengthXorMask =
xor_mask_length; pointer_color->andMaskData = NULL;
This causes the guard condition in the RDP plugin to fail to copy bitmap data
from the server. It appears as if FreeRDP [correctly
handles|https://github.com/FreeRDP/FreeRDP/blob/eb7adaec46eceaa4b247dc664dcce2d65a5edead/libfreerdp/codec/color.c#L322]
the image data in `freerdp_image_copy_from_pointer_data` if `lengthAndMask` ==
0:
{code:java}
if (!xorMask || (xorMaskLength == 0))
return FALSE;
if (!andMask || (andMaskLength == 0))
return FALSE; {code}
I believe this guard condition is probably not necessary; removing it resolves
the issue for me. I tested against both Gnome Remote Desktop and a Windows 11
Professional instance.
Please let me know if you'd like any additional information or testing done.
This was tested with Guacamole 1.4.0 from Docker Hub (guacamole/guacamole:1.4.0
and guacamole/guacd:1.4.0). Testing against a fresh install of Fedora 37/Gnome
43.
was:
When connecting to a [Gnome Remote
Desktop|https://gitlab.gnome.org/GNOME/gnome-remote-desktop] RDP instance the
mouse cursor is created but the image data is never copied into the cursor's
pixel buffer resulting in a garbled bitmap containing uninitialized data:
!image-2022-11-20-19-59-57-478.png|width=664,height=311!
This appears to happen because of this guard condition in
src/protocols/rdp/pointer.c:
```c
if (pointer->andMaskData && pointer->xorMaskData)
```
It appears when Gnome Remote Desktop [initializes
cursors|https://gitlab.gnome.org/GNOME/gnome-remote-desktop/-/blob/master/src/grd-session-rdp.c#L591]
when starting the session it sets `andMaskData` to NULL with a length of zero:
```c
pointer_color->lengthAndMask = 0;
pointer_color->lengthXorMask = xor_mask_length;
pointer_color->andMaskData = NULL;
```
This causes the guard condition in the RDP plugin to fail to copy bitmap data
from the server. It appears as if FreeRDP [correctly
handles|https://github.com/FreeRDP/FreeRDP/blob/eb7adaec46eceaa4b247dc664dcce2d65a5edead/libfreerdp/codec/color.c#L322]
the image data in `freerdp_image_copy_from_pointer_data` if `lengthAndMask` ==
0:
```c
if (!xorMask || (xorMaskLength == 0))
return FALSE;
if (!andMask || (andMaskLength == 0))
return FALSE;
```
I believe this guard condition is probably not necessary; removing it resolves
the issue for me. I tested against both Gnome Remote Desktop and a Windows 11
Professional instance.
Please let me know if you'd like any additional information or testing done.
This was tested with Guacamole 1.4.0 from Docker Hub (guacamole/guacamole:1.4.0
and guacamole/guacd:1.4.0). Testing against a fresh install of Fedora 37/Gnome
43.
> Cursor Improperly Initialized when Connecting to Gnome Remote Desktop via RDP
> -----------------------------------------------------------------------------
>
> Key: GUACAMOLE-1717
> URL: https://issues.apache.org/jira/browse/GUACAMOLE-1717
> Project: Guacamole
> Issue Type: Bug
> Components: RDP
> Affects Versions: 1.4.0
> Reporter: Mike Powers
> Priority: Minor
> Attachments: image-2022-11-20-20-14-11-333.png
>
>
> When connecting to a [Gnome Remote
> Desktop|https://gitlab.gnome.org/GNOME/gnome-remote-desktop] RDP instance the
> mouse cursor is created but the image data is never copied into the cursor's
> pixel buffer resulting in a garbled bitmap containing uninitialized data:
> !image-2022-11-20-20-14-11-333.png|width=656,height=355!
> This appears to happen because of this [guard
> condition|https://github.com/apache/guacamole-server/blob/3ca6bb0a61715d17dc263e565e6ce0de7354606c/src/protocols/rdp/pointer.c#L50]
> in src/protocols/rdp/pointer.c (line 49):
> {code:java}
> if (pointer->andMaskData && pointer->xorMaskData) {code}
>
> It appears when Gnome Remote Desktop [initializes
> cursors|https://gitlab.gnome.org/GNOME/gnome-remote-desktop/-/blob/master/src/grd-session-rdp.c#L591]
> when starting the session it sets `andMaskData` to NULL with a length of
> zero:
> pointer_color->lengthAndMask = 0; pointer_color->lengthXorMask =
> xor_mask_length; pointer_color->andMaskData = NULL;
>
> This causes the guard condition in the RDP plugin to fail to copy bitmap data
> from the server. It appears as if FreeRDP [correctly
> handles|https://github.com/FreeRDP/FreeRDP/blob/eb7adaec46eceaa4b247dc664dcce2d65a5edead/libfreerdp/codec/color.c#L322]
> the image data in `freerdp_image_copy_from_pointer_data` if `lengthAndMask`
> == 0:
> {code:java}
> if (!xorMask || (xorMaskLength == 0))
> return FALSE;
> if (!andMask || (andMaskLength == 0))
> return FALSE; {code}
>
>
> I believe this guard condition is probably not necessary; removing it
> resolves the issue for me. I tested against both Gnome Remote Desktop and a
> Windows 11 Professional instance.
> Please let me know if you'd like any additional information or testing done.
> This was tested with Guacamole 1.4.0 from Docker Hub
> (guacamole/guacamole:1.4.0 and guacamole/guacd:1.4.0). Testing against a
> fresh install of Fedora 37/Gnome 43.
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