These functions can be used to send already compressed jpegs to a
client, circumventing the usual rect/region update methods which
operate on a raw rgb framebuffer. Rename the functions with the usual
rfb prefix and add the prototypes in rfb.h.
Signed-off-by: Eddie James <firstname.lastname@example.org>
This patch constrains a client cut text length to 1 MB. Otherwise
a client could make server allocate 2 GB of memory and that seems to
be to much to classify it as a denial of service.
The limit also prevents from an integer overflow followed by copying
an uninitilized memory when processing msg.cct.length value larger
than SIZE_MAX or INT_MAX - sz_rfbClientCutTextMsg.
This patch also corrects accepting length value of zero (malloc(0) is
interpreted on differnet systems differently).
- As with the encoder, the decoder now uses the TurboJPEG wrapper, which
allows it to decode JPEG images directly into the framebuffer. This
eliminates a buffer copy (CopyRectangle()) as well as the expensive
RGB pixel conversion in DecompressJpegRectBPP(). The TurboJPEG
wrapper performs RGB pixel conversion more optimally, and only when
necessary (it uses the libjpeg-turbo colorspace extensions when
available, in order to avoid RGB conversion.)
- The other Tight subencoding types are also now decoded directly into
the framebuffer, which eliminates buffer copies.
- The Tight decoder now supports the rfbTightNoZlib extension, which
allows the server to bypass zlib compression when Compression Level 0
is selected. The encoder already supports this extension. Passing
the data stream through zlib when Compression Level 0 is selected
needlessly wastes CPU time, since all zlib is doing is copying the
data internally into its own structures.
fix critical heap-based buffer overflow which allowed easy modification
of a return address via an overwritten function pointer
fix bug causing connections to fail due a "one websocket frame = one
ws_read" assumption, which failed with LibVNCServer-0.9.11
refactor websocket Hybi decode to use a simple state machine for
decoding of websocket frames