The check for existence of `/usr/spool/sockets/X11/<n>` has been
removed. This file is only relevant on HP-UX, and TigerVNC dropped
support for HP-UX in commit 31e5aa3.
If using SSecurityPlain and the user specifies an empty username
and password, it will invoke InStream::checkNoWait(0) which will
cause a division by zero when calculating the number of available
items.
Enhance InStream::check() to behave properly when asked for
zero items, or zero sized items.
Add comments to InStream::check(), InStream::checkNoWait(),
and InStream::readBytes() to document expected behaviour
when requested to check or read zero items, or an item with
zero size.
It seems like many of the X11 operations can end up with no pixels
actually changing. So instead of discovering and adding workarounds for
each individually we'll just check very region added if it's empty.
Created a new subclass of Exception called GAIException() that will
handle error messages from getaddrinfo() instead of letting Exception()
handle it. GAIException() will make use of gai_strerror() to map the
error code to text. On Windows, gai_strerrorW() must be used if the text
is encoded with UTF-8.
The previous error messages did not support Unicode characters. This
commit will use UTF-8 encoding to be able to display error messages in
every language.
This allows Xvnc to build with xorg-server 1.20.7, which requires OS
layers to implement a ddxInputThreadInit function when configured with
--enable-input-thread (the default).
relevant xorg-server commit: e3f26605d85d987da434640f52646d728f1fe919
There might be more bytes left in the current TLS record, even if
there is nothing on the underlying stream. Make sure we properly
return this when we aren't being requested to block.
When used with -fg we expect the startup script to remain running until
the session is over. This will not happen if the session command is put
in the background using &.
Our fast paths assume that each channel fits in to a separate byte.
That means the shift needs to be a multiple of 8. Start actually
checking this so that a client cannot trip us up and possibly cause
incorrect code exection.
Issue found by Pavel Cheremushkin from Kaspersky Lab.
We use a lot of lengths given to us over the network, so be more
paranoid about them causing an overflow as otherwise an attacker
might trick us in to overwriting other memory.
This primarily affects the client which often gets lengths from the
server, but there are also some scenarios where the server might
theoretically be vulnerable.
Issue found by Pavel Cheremushkin from Kaspersky Lab.
Provides safety against them accidentally becoming negative because
of bugs in the calculations.
Also does the same to CharArray and friends as they were strongly
connection to the stream objects.
Otherwise we might be tricked in to reading and writing things at
incorrect offsets for pixels which ultimately could result in an
attacker writing things to the stack or heap and executing things
they shouldn't.
This only affects the server as the client never uses the pixel
format suggested by th server.
Issue found by Pavel Cheremushkin from Kaspersky Lab.
We always assumed there would be one pixel per row so a rect with
a zero width would result in us writing to unknown memory.
This could theoretically be used by a malicious server to inject
code in to the viewer process.
Issue found by Pavel Cheremushkin from Kaspersky Lab.
Move the checks around to avoid missing cases where we might access
memory that is no longer valid. Also avoid touching the underlying
stream implicitly (e.g. via the destructor) as it might also no
longer be valid.
A malicious server could theoretically use this for remote code
execution in the client.
Issue found by Pavel Cheremushkin from Kaspersky Lab
