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Literals header fields use little endian convention

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This commit is contained in:
Yann Collet
2016-07-22 14:37:09 +02:00
parent 6fa05a2371
commit 198e6aac44
3 changed files with 95 additions and 89 deletions
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lib/decompress/zstd_decompress.c
+57 -44
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@@ -397,9 +397,9 @@ size_t ZSTD_getFrameParams(ZSTD_frameParams* fparamsPtr, const void* src, size_t
* compatible with legacy mode
* @return : decompressed size if known, 0 otherwise
note : 0 can mean any of the following :
- decompressed size is not provided within frame header
- decompressed size is not present within frame header
- frame header unknown / not supported
- frame header not completely provided (`srcSize` too small) */
- frame header not complete (`srcSize` too small) */
unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize)
{
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT==1)
@@ -464,33 +464,42 @@ size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
if (srcSize < MIN_CBLOCK_SIZE) return ERROR(corruption_detected);
switch((litBlockType_t)(istart[0]>> 6))
switch((litBlockType_t)(istart[0] & 3))
{
case lbt_huffman:
{ size_t litSize, litCSize, singleStream=0;
U32 lhSize = (istart[0] >> 4) & 3;
{ size_t lhSize, litSize, litCSize, singleStream=0;
U32 const lhlCode = (istart[0] >> 2) & 3;
if (srcSize < 5) return ERROR(corruption_detected); /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need up to 5 for lhSize, + cSize (+nbSeq) */
switch(lhSize)
switch(lhlCode)
{
case 0: case 1: default: /* note : default is impossible, since lhSize into [0..3] */
case 1:
singleStream = 1;
/* fall through */
case 0: default: /* note : default is impossible, since lhlCode into [0..3] */
/* 2 - 2 - 10 - 10 */
lhSize=3;
singleStream = istart[0] & 16;
litSize = ((istart[0] & 15) << 6) + (istart[1] >> 2);
litCSize = ((istart[1] & 3) << 8) + istart[2];
break;
{ U32 const lhc = MEM_readLE24(istart) >> 4;
lhSize = 3;
litSize = lhc & 0x3FF;
litCSize = lhc >> 10;
break;
}
case 2:
/* 2 - 2 - 14 - 14 */
lhSize=4;
litSize = ((istart[0] & 15) << 10) + (istart[1] << 2) + (istart[2] >> 6);
litCSize = ((istart[2] & 63) << 8) + istart[3];
break;
{ U32 const lhc = MEM_readLE32(istart) >> 4;
lhSize = 4;
litSize = lhc & 0x3FFF;
litCSize = lhc >> 14;
break;
}
case 3:
/* 2 - 2 - 18 - 18 */
lhSize=5;
litSize = ((istart[0] & 15) << 14) + (istart[1] << 6) + (istart[2] >> 2);
litCSize = ((istart[2] & 3) << 16) + (istart[3] << 8) + istart[4];
break;
{ U64 const lhc = (MEM_readLE32(istart) + (((U64)istart[4]) << 32)) >> 4;
lhSize = 5;
litSize = lhc & 0x3FFFF;
litCSize = lhc >> 18;
break;
}
}
if (litSize > ZSTD_BLOCKSIZE_ABSOLUTEMAX) return ERROR(corruption_detected);
if (litCSize + lhSize > srcSize) return ERROR(corruption_detected);
@@ -501,23 +510,23 @@ size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
return ERROR(corruption_detected);
dctx->litPtr = dctx->litBuffer;
dctx->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+8;
dctx->litBufSize = ZSTD_BLOCKSIZE_ABSOLUTEMAX+WILDCOPY_OVERLENGTH;
dctx->litSize = litSize;
dctx->litEntropy = 1;
return litCSize + lhSize;
}
case lbt_repeat:
{ size_t litSize, litCSize;
U32 lhSize = ((istart[0]) >> 4) & 3;
if (lhSize != 1) /* only case supported for now : small litSize, single stream */
{ size_t litSize, litCSize, lhSize;
U32 const lhc = MEM_readLE24(istart) >> 4;
if ((((istart[0]) >> 2) & 3) != 1) /* only case supported for now : small litSize, single stream */
return ERROR(corruption_detected);
if (dctx->litEntropy==0)
return ERROR(dictionary_corrupted);
/* 2 - 2 - 10 - 10 */
lhSize=3;
litSize = ((istart[0] & 15) << 6) + (istart[1] >> 2);
litCSize = ((istart[1] & 3) << 8) + istart[2];
lhSize = 3;
litSize = lhc & 0x3FF;
litCSize = lhc >> 10;
if (litCSize + lhSize > srcSize) return ERROR(corruption_detected);
{ size_t const errorCode = HUF_decompress1X4_usingDTable(dctx->litBuffer, litSize, istart+lhSize, litCSize, dctx->hufTable);
@@ -529,19 +538,21 @@ size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
return litCSize + lhSize;
}
case lbt_raw:
{ size_t litSize;
U32 lhSize = ((istart[0]) >> 4) & 3;
switch(lhSize)
{ size_t litSize, lhSize;
U32 const lhlCode = ((istart[0]) >> 2) & 3;
switch(lhlCode)
{
case 0: case 1: default: /* note : default is impossible, since lhSize into [0..3] */
lhSize=1;
litSize = istart[0] & 31;
case 0: case 2: default: /* note : default is impossible, since lhlCode into [0..3] */
lhSize = 1;
litSize = istart[0] >> 3;
break;
case 2:
litSize = ((istart[0] & 15) << 8) + istart[1];
case 1:
lhSize = 2;
litSize = MEM_readLE16(istart) >> 4;
break;
case 3:
litSize = ((istart[0] & 15) << 16) + (istart[1] << 8) + istart[2];
lhSize = 3;
litSize = MEM_readLE24(istart) >> 4;
break;
}
@@ -560,19 +571,21 @@ size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
return lhSize+litSize;
}
case lbt_rle:
{ size_t litSize;
U32 lhSize = ((istart[0]) >> 4) & 3;
switch(lhSize)
{ U32 const lhlCode = ((istart[0]) >> 2) & 3;
size_t litSize, lhSize;
switch(lhlCode)
{
case 0: case 1: default: /* note : default is impossible, since lhSize into [0..3] */
case 0: case 2: default: /* note : default is impossible, since lhlCode into [0..3] */
lhSize = 1;
litSize = istart[0] & 31;
litSize = istart[0] >> 3;
break;
case 2:
litSize = ((istart[0] & 15) << 8) + istart[1];
case 1:
lhSize = 2;
litSize = MEM_readLE16(istart) >> 4;
break;
case 3:
litSize = ((istart[0] & 15) << 16) + (istart[1] << 8) + istart[2];
lhSize = 3;
litSize = MEM_readLE24(istart) >> 4;
if (srcSize<4) return ERROR(corruption_detected); /* srcSize >= MIN_CBLOCK_SIZE == 3; here we need lhSize+1 = 4 */
break;
}