Commit Graph

618 Commits

Author SHA1 Message Date
Pierre Ossman
06fd7ac061 Use sys/time.h on Windows as well
Modern MinGW seems to provide this, so simplify things a bit. This also
side steps some of the issue of the windows.h/winsock2.h include
ordering.
2020-09-21 13:05:50 +03:00
Pierre Ossman
b7dc4a16fe Handle pending data in TLS buffers
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.
2020-09-21 13:00:41 +03:00
Pierre Ossman
3ee909ffe6 Don't background the main session command
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 &.
2020-09-21 12:59:06 +03:00
Pierre Ossman
c3279914c1 Fix link order of nettle and hogweed
Hogweed needs nettle, not the other way around. So make sure they
are specified in the correct order for the static link to succeed.
2020-09-21 12:58:11 +03:00
Pierre Ossman
ed73ac2aa7 Handle pixel formats with odd shift values
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.
2020-09-21 12:56:53 +03:00
Pierre Ossman
ae6cbd19e9 Be defensive about overflows in stream objects
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.
2020-09-21 12:56:23 +03:00
Pierre Ossman
259f1055cb Use size_t for lengths in stream objects
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.
2020-09-21 12:55:59 +03:00
Pierre Ossman
346fccb96c Remove unused FixedMemOutStream 2020-09-21 12:48:20 +03:00
Pierre Ossman
1d5aaf54f8 Add sanity checks for PixelFormat shift values
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.
2020-09-21 12:47:56 +03:00
Pierre Ossman
9f7abaea3a Fix depth sanity test in PixelFormat 2020-09-21 12:47:22 +03:00
Pierre Ossman
1224cbdc21 Handle empty Tight gradient rects
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.
2020-09-21 12:46:27 +03:00
Pierre Ossman
6a3f711878 Add write protection to OffsetPixelBuffer
No one should every try to write to this buffer. Enforce that by
throwing an exception if any one tries to get a writeable pointer
to the data.
2020-09-21 12:45:51 +03:00
Pierre Ossman
3282836baf Make ZlibInStream more robust against failures
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
2020-09-21 12:40:12 +03:00
Lauri Kasanen
ac06594b12 Add .gitignore 2020-09-21 12:33:19 +03:00
Kasm
5da407c11f
Update README.md 2020-09-20 09:11:28 -04:00
Kasm
313961153c
Update install.sh
Modified installer to use release on GitHub
2020-09-20 09:04:35 -04:00
matt
408c005d3e Initial commit 2020-09-20 12:16:44 +00:00
Kasm
09a4460ddb
Initial commit 2020-09-13 12:50:42 -04:00