/**
* FreeRDP: A Remote Desktop Protocol Implementation
* ZGFX (RDP8) Bulk Data Compression
*
* Copyright 2014 Marc-Andre Moreau <marcandre.moreau@gmail.com>
* Copyright 2017 Armin Novak <armin.novak@thincast.com>
* Copyright 2017 Thincast Technologies GmbH
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <winpr/crt.h>
#include <winpr/print.h>
#include <winpr/bitstream.h>
#include <freerdp/log.h>
#include <freerdp/codec/zgfx.h>
#define TAG FREERDP_TAG("codec")
/**
* RDP8 Compressor Limits:
*
* Maximum number of uncompressed bytes in a single segment: 65535
* Maximum match distance / minimum history size: 2500000 bytes.
* Maximum number of segments: 65535
* Maximum expansion of a segment (when compressed size exceeds uncompressed): 1000 bytes
* Minimum match length: 3 bytes
*/
struct _ZGFX_TOKEN
{
UINT32 prefixLength;
UINT32 prefixCode;
UINT32 valueBits;
UINT32 tokenType;
UINT32 valueBase;
};
typedef struct _ZGFX_TOKEN ZGFX_TOKEN;
struct _ZGFX_CONTEXT
{
BOOL Compressor;
const BYTE* pbInputCurrent;
const BYTE* pbInputEnd;
UINT32 bits;
UINT32 cBitsRemaining;
UINT32 BitsCurrent;
UINT32 cBitsCurrent;
BYTE OutputBuffer[65536];
UINT32 OutputCount;
BYTE HistoryBuffer[2500000];
UINT32 HistoryIndex;
UINT32 HistoryBufferSize;
};
static const ZGFX_TOKEN ZGFX_TOKEN_TABLE[] =
{
// len code vbits type vbase
{ 1, 0, 8, 0, 0 }, // 0
{ 5, 17, 5, 1, 0 }, // 10001
{ 5, 18, 7, 1, 32 }, // 10010
{ 5, 19, 9, 1, 160 }, // 10011
{ 5, 20, 10, 1, 672 }, // 10100
{ 5, 21, 12, 1, 1696 }, // 10101
{ 5, 24, 0, 0, 0x00 }, // 11000
{ 5, 25, 0, 0, 0x01 }, // 11001
{ 6, 44, 14, 1, 5792 }, // 101100
{ 6, 45, 15, 1, 22176 }, // 101101
{ 6, 52, 0, 0, 0x02 }, // 110100
{ 6, 53, 0, 0, 0x03 }, // 110101
{ 6, 54, 0, 0, 0xFF }, // 110110
{ 7, 92, 18, 1, 54944 }, // 1011100
{ 7, 93, 20, 1, 317088 }, // 1011101
{ 7, 110, 0, 0, 0x04 }, // 1101110
{ 7, 111, 0, 0, 0x05 }, // 1101111
{ 7, 112, 0, 0, 0x06 }, // 1110000
{ 7, 113, 0, 0, 0x07 }, // 1110001
{ 7, 114, 0, 0, 0x08 }, // 1110010
{ 7, 115, 0, 0, 0x09 }, // 1110011
{ 7, 116, 0, 0, 0x0A }, // 1110100
{ 7, 117, 0, 0, 0x0B }, // 1110101
{ 7, 118, 0, 0, 0x3A }, // 1110110
{ 7, 119, 0, 0, 0x3B }, // 1110111
{ 7, 120, 0, 0, 0x3C }, // 1111000
{ 7, 121, 0, 0, 0x3D }, // 1111001
{ 7, 122, 0, 0, 0x3E }, // 1111010
{ 7, 123, 0, 0, 0x3F }, // 1111011
{ 7, 124, 0, 0, 0x40 }, // 1111100
{ 7, 125, 0, 0, 0x80 }, // 1111101
{ 8, 188, 20, 1, 1365664 }, // 10111100
{ 8, 189, 21, 1, 2414240 }, // 10111101
{ 8, 252, 0, 0, 0x0C }, // 11111100
{ 8, 253, 0, 0, 0x38 }, // 11111101
{ 8, 254, 0, 0, 0x39 }, // 11111110
{ 8, 255, 0, 0, 0x66 }, // 11111111
{ 9, 380, 22, 1, 4511392 }, // 101111100
{ 9, 381, 23, 1, 8705696 }, // 101111101
{ 9, 382, 24, 1, 17094304 }, // 101111110
{ 0 }
};
static INLINE BOOL zgfx_GetBits(ZGFX_CONTEXT* _zgfx, UINT32 _nbits)
{
if (!_zgfx)
return FALSE;
while (_zgfx->cBitsCurrent < _nbits)
{
_zgfx->BitsCurrent <<= 8;
if (_zgfx->pbInputCurrent < _zgfx->pbInputEnd)
_zgfx->BitsCurrent += *(_zgfx->pbInputCurrent)++;
_zgfx->cBitsCurrent += 8;
}
_zgfx->cBitsRemaining -= _nbits;
_zgfx->cBitsCurrent -= _nbits;
_zgfx->bits = _zgfx->BitsCurrent >> _zgfx->cBitsCurrent;
_zgfx->BitsCurrent &= ((1 << _zgfx->cBitsCurrent) - 1);
return TRUE;
}
static void zgfx_history_buffer_ring_write(ZGFX_CONTEXT* zgfx, const BYTE* src, size_t count)
{
UINT32 front;
if (count <= 0)
return;
if (count > zgfx->HistoryBufferSize)
{
const size_t residue = count - zgfx->HistoryBufferSize;
count = zgfx->HistoryBufferSize;
src += residue;
zgfx->HistoryIndex = (zgfx->HistoryIndex + residue) % zgfx->HistoryBufferSize;
}
if (zgfx->HistoryIndex + count <= zgfx->HistoryBufferSize)
{
CopyMemory(&(zgfx->HistoryBuffer[zgfx->HistoryIndex]), src, count);
if ((zgfx->HistoryIndex += count) == zgfx->HistoryBufferSize)
zgfx->HistoryIndex = 0;
}
else
{
front = zgfx->HistoryBufferSize - zgfx->HistoryIndex;
CopyMemory(&(zgfx->HistoryBuffer[zgfx->HistoryIndex]), src, front);
CopyMemory(zgfx->HistoryBuffer, &src[front], count - front);
zgfx->HistoryIndex = count - front;
}
}
static void zgfx_history_buffer_ring_read(ZGFX_CONTEXT* zgfx, int offset, BYTE* dst, UINT32 count)
{
UINT32 front;
UINT32 index;
UINT32 bytes;
UINT32 valid;
UINT32 bytesLeft;
BYTE* dptr = dst;
BYTE* origDst = dst;
if (count <= 0)
return;
bytesLeft = count;
index = (zgfx->HistoryIndex + zgfx->HistoryBufferSize - offset) % zgfx->HistoryBufferSize;
bytes = MIN(bytesLeft, offset);
if ((index + bytes) <= zgfx->HistoryBufferSize)
{
CopyMemory(dptr, &(zgfx->HistoryBuffer[index]), bytes);
}
else
{
front = zgfx->HistoryBufferSize - index;
CopyMemory(dptr, &(zgfx->HistoryBuffer[index]), front);
CopyMemory(&dptr[front], zgfx->HistoryBuffer, bytes - front);
}
if ((bytesLeft -= bytes) == 0)
return;
dptr += bytes;
valid = bytes;
do
{
bytes = valid;
if (bytes > bytesLeft)
bytes = bytesLeft;
CopyMemory(dptr, origDst, bytes);
dptr += bytes;
valid <<= 1;
}
while ((bytesLeft -= bytes) > 0);
}
static BOOL zgfx_decompress_segment(ZGFX_CONTEXT* zgfx, wStream* stream, size_t segmentSize)
{
BYTE c;
BYTE flags;
UINT32 extra = 0;
int opIndex;
int haveBits;
int inPrefix;
UINT32 count;
UINT32 distance;
BYTE* pbSegment;
size_t cbSegment;
if (!zgfx || !stream)
return FALSE;
cbSegment = segmentSize - 1;
if ((Stream_GetRemainingLength(stream) < segmentSize) || (segmentSize < 1) ||
(segmentSize > UINT32_MAX))
return FALSE;
Stream_Read_UINT8(stream, flags); /* header (1 byte) */
zgfx->OutputCount = 0;
pbSegment = Stream_Pointer(stream);
Stream_Seek(stream, cbSegment);
if (!(flags & PACKET_COMPRESSED))
{
zgfx_history_buffer_ring_write(zgfx, pbSegment, cbSegment);
if (cbSegment > sizeof(zgfx->OutputBuffer))
return FALSE;
CopyMemory(zgfx->OutputBuffer, pbSegment, cbSegment);
zgfx->OutputCount = cbSegment;
return TRUE;
}
zgfx->pbInputCurrent = pbSegment;
zgfx->pbInputEnd = &pbSegment[cbSegment - 1];
/* NumberOfBitsToDecode = ((NumberOfBytesToDecode - 1) * 8) - ValueOfLastByte */
zgfx->cBitsRemaining = 8 * (cbSegment - 1) - *zgfx->pbInputEnd;
zgfx->cBitsCurrent = 0;
zgfx->BitsCurrent = 0;
while (zgfx->cBitsRemaining)
{
haveBits = 0;
inPrefix = 0;
for (opIndex = 0; ZGFX_TOKEN_TABLE[opIndex].prefixLength != 0; opIndex++)
{
while (haveBits < ZGFX_TOKEN_TABLE[opIndex].prefixLength)
{
zgfx_GetBits(zgfx, 1);
inPrefix = (inPrefix << 1) + zgfx->bits;
haveBits++;
}
if (inPrefix == ZGFX_TOKEN_TABLE[opIndex].prefixCode)
{
if (ZGFX_TOKEN_TABLE[opIndex].tokenType == 0)
{
/* Literal */
zgfx_GetBits(zgfx, ZGFX_TOKEN_TABLE[opIndex].valueBits);
c = (BYTE)(ZGFX_TOKEN_TABLE[opIndex].valueBase + zgfx->bits);
zgfx->HistoryBuffer[zgfx->HistoryIndex] = c;
if (++zgfx->HistoryIndex == zgfx->HistoryBufferSize)
zgfx->HistoryIndex = 0;
if (zgfx->OutputCount >= sizeof(zgfx->OutputBuffer))
return FALSE;
zgfx->OutputBuffer[zgfx->OutputCount++] = c;
}
else
{
zgfx_GetBits(zgfx, ZGFX_TOKEN_TABLE[opIndex].valueBits);
distance = ZGFX_TOKEN_TABLE[opIndex].valueBase + zgfx->bits;
if (distance != 0)
{
/* Match */
zgfx_GetBits(zgfx, 1);
if (zgfx->bits == 0)
{
count = 3;
}
else
{
count = 4;
extra = 2;
zgfx_GetBits(zgfx, 1);
while (zgfx->bits == 1)
{
count *= 2;
extra++;
zgfx_GetBits(zgfx, 1);
}
zgfx_GetBits(zgfx, extra);
count += zgfx->bits;
}
if (count > sizeof(zgfx->OutputBuffer) - zgfx->OutputCount)
return FALSE;
zgfx_history_buffer_ring_read(zgfx, distance, &(zgfx->OutputBuffer[zgfx->OutputCount]), count);
zgfx_history_buffer_ring_write(zgfx, &(zgfx->OutputBuffer[zgfx->OutputCount]), count);
zgfx->OutputCount += count;
}
else
{
/* Unencoded */
zgfx_GetBits(zgfx, 15);
count = zgfx->bits;
zgfx->cBitsRemaining -= zgfx->cBitsCurrent;
zgfx->cBitsCurrent = 0;
zgfx->BitsCurrent = 0;
if (count > sizeof(zgfx->OutputBuffer) - zgfx->OutputCount)
return FALSE;
CopyMemory(&(zgfx->OutputBuffer[zgfx->OutputCount]), zgfx->pbInputCurrent, count);
zgfx_history_buffer_ring_write(zgfx, zgfx->pbInputCurrent, count);
zgfx->pbInputCurrent += count;
zgfx->cBitsRemaining -= (8 * count);
zgfx->OutputCount += count;
}
}
break;
}
}
}
return TRUE;
}
int zgfx_decompress(ZGFX_CONTEXT* zgfx, const BYTE* pSrcData, UINT32 SrcSize, BYTE** ppDstData,
UINT32* pDstSize, UINT32 flags)
{
int status = -1;
BYTE descriptor;
wStream* stream = Stream_New((BYTE*)pSrcData, SrcSize);
if (!stream)
return -1;
if (Stream_GetRemainingLength(stream) < 1)
goto fail;
Stream_Read_UINT8(stream, descriptor); /* descriptor (1 byte) */
if (descriptor == ZGFX_SEGMENTED_SINGLE)
{
if (!zgfx_decompress_segment(zgfx, stream, Stream_GetRemainingLength(stream)))
goto fail;
*ppDstData = NULL;
if (zgfx->OutputCount > 0)
*ppDstData = (BYTE*) malloc(zgfx->OutputCount);
if (!*ppDstData)
goto fail;
*pDstSize = zgfx->OutputCount;
CopyMemory(*ppDstData, zgfx->OutputBuffer, zgfx->OutputCount);
}
else if (descriptor == ZGFX_SEGMENTED_MULTIPART)
{
UINT32 segmentSize;
UINT16 segmentNumber;
UINT16 segmentCount;
UINT32 uncompressedSize;
BYTE* pConcatenated;
size_t used = 0;
if (Stream_GetRemainingLength(stream) < 6)
goto fail;
Stream_Read_UINT16(stream, segmentCount); /* segmentCount (2 bytes) */
Stream_Read_UINT32(stream, uncompressedSize); /* uncompressedSize (4 bytes) */
if (Stream_GetRemainingLength(stream) < segmentCount * sizeof(UINT32))
goto fail;
pConcatenated = (BYTE*) malloc(uncompressedSize);
if (!pConcatenated)
goto fail;
*ppDstData = pConcatenated;
*pDstSize = uncompressedSize;
for (segmentNumber = 0; segmentNumber < segmentCount; segmentNumber++)
{
if (Stream_GetRemainingLength(stream) < sizeof(UINT32))
goto fail;
Stream_Read_UINT32(stream, segmentSize); /* segmentSize (4 bytes) */
if (!zgfx_decompress_segment(zgfx, stream, segmentSize))
goto fail;
if (zgfx->OutputCount > UINT32_MAX - used)
goto fail;
if (used + zgfx->OutputCount > uncompressedSize)
goto fail;
CopyMemory(pConcatenated, zgfx->OutputBuffer, zgfx->OutputCount);
pConcatenated += zgfx->OutputCount;
used += zgfx->OutputCount;
}
}
else
{
goto fail;
}
status = 1;
fail:
Stream_Free(stream, FALSE);
return status;
}
static BOOL zgfx_compress_segment(ZGFX_CONTEXT* zgfx, wStream* s, const BYTE* pSrcData,
UINT32 SrcSize, UINT32* pFlags)
{
/* FIXME: Currently compression not implemented. Just copy the raw source */
if (!Stream_EnsureRemainingCapacity(s, SrcSize + 1))
{
WLog_ERR(TAG, "Stream_EnsureRemainingCapacity failed!");
return FALSE;
}
(*pFlags) |= ZGFX_PACKET_COMPR_TYPE_RDP8; /* RDP 8.0 compression format */
Stream_Write_UINT8(s, (*pFlags)); /* header (1 byte) */
Stream_Write(s, pSrcData, SrcSize);
return TRUE;
}
int zgfx_compress_to_stream(ZGFX_CONTEXT* zgfx, wStream* sDst, const BYTE* pUncompressed,
UINT32 uncompressedSize, UINT32* pFlags)
{
int fragment;
UINT16 maxLength;
UINT32 totalLength;
size_t posSegmentCount = 0;
const BYTE* pSrcData;
int status = 0;
maxLength = ZGFX_SEGMENTED_MAXSIZE;
totalLength = uncompressedSize;
pSrcData = pUncompressed;
for (fragment = 0; (totalLength > 0) || (fragment == 0); fragment++)
{
UINT32 SrcSize;
size_t posDstSize;
size_t posDataStart;
UINT32 DstSize;
SrcSize = (totalLength > maxLength) ? maxLength : totalLength;
posDstSize = 0;
totalLength -= SrcSize;
/* Ensure we have enough space for headers */
if (!Stream_EnsureRemainingCapacity(sDst, 12))
{
WLog_ERR(TAG, "Stream_EnsureRemainingCapacity failed!");
return -1;
}
if (fragment == 0)
{
/* First fragment */
/* descriptor (1 byte) */
Stream_Write_UINT8(sDst, (totalLength == 0) ?
ZGFX_SEGMENTED_SINGLE : ZGFX_SEGMENTED_MULTIPART);
if (totalLength > 0)
{
posSegmentCount = Stream_GetPosition(sDst); /* segmentCount (2 bytes) */
Stream_Seek(sDst, 2);
Stream_Write_UINT32(sDst, uncompressedSize); /* uncompressedSize (4 bytes) */
}
}
if (fragment > 0 || totalLength > 0)
{
/* Multipart */
posDstSize = Stream_GetPosition(sDst); /* size (4 bytes) */
Stream_Seek(sDst, 4);
}
posDataStart = Stream_GetPosition(sDst);
if (!zgfx_compress_segment(zgfx, sDst, pSrcData, SrcSize, pFlags))
return -1;
if (posDstSize)
{
/* Fill segment data size */
DstSize = Stream_GetPosition(sDst) - posDataStart;
Stream_SetPosition(sDst, posDstSize);
Stream_Write_UINT32(sDst, DstSize);
Stream_SetPosition(sDst, posDataStart + DstSize);
}
pSrcData += SrcSize;
}
Stream_SealLength(sDst);
/* fill back segmentCount */
if (posSegmentCount)
{
Stream_SetPosition(sDst, posSegmentCount);
Stream_Write_UINT16(sDst, fragment);
Stream_SetPosition(sDst, Stream_Length(sDst));
}
return status;
}
int zgfx_compress(ZGFX_CONTEXT* zgfx, const BYTE* pSrcData, UINT32 SrcSize, BYTE** ppDstData,
UINT32* pDstSize, UINT32* pFlags)
{
int status;
wStream* s = Stream_New(NULL, SrcSize);
status = zgfx_compress_to_stream(zgfx, s, pSrcData, SrcSize, pFlags);
(*ppDstData) = Stream_Buffer(s);
(*pDstSize) = Stream_GetPosition(s);
Stream_Free(s, FALSE);
return status;
}
void zgfx_context_reset(ZGFX_CONTEXT* zgfx, BOOL flush)
{
zgfx->HistoryIndex = 0;
}
ZGFX_CONTEXT* zgfx_context_new(BOOL Compressor)
{
ZGFX_CONTEXT* zgfx;
zgfx = (ZGFX_CONTEXT*) calloc(1, sizeof(ZGFX_CONTEXT));
if (zgfx)
{
zgfx->Compressor = Compressor;
zgfx->HistoryBufferSize = sizeof(zgfx->HistoryBuffer);
zgfx_context_reset(zgfx, FALSE);
}
return zgfx;
}
void zgfx_context_free(ZGFX_CONTEXT* zgfx)
{
free(zgfx);
}