Mercurial > vba-linux

     1 // Archive/LzmaIn.cpp

     2 

     3 #include "StdAfx.h"

     4 

     5 #include "LzmaIn.h"

     6 

     7 #include "../../Common/StreamUtils.h"

     8 

     9 namespace NArchive {

    10 namespace NLzma {

    11  

    12 static bool CheckDictSize(const Byte *p)

    13 {

    14   UInt32 dicSize = GetUi32(p);

    15   int i;

    16   for (i = 1; i <= 30; i++)

    17     if (dicSize == ((UInt32)2 << i) || dicSize == ((UInt32)3 << i))

    18       return true;

    19   return false;

    20 }

    21 

    22 HRESULT ReadStreamHeader(ISequentialInStream *inStream, CHeader &block)

    23 {

    24   Byte sig[5 + 9];

    25   RINOK(ReadStream_FALSE(inStream, sig, 5 + 8));

    26 

    27   const Byte kMaxProp0Val = 5 * 5 * 9 - 1;

    28   if (sig[0] > kMaxProp0Val)

    29     return S_FALSE;

    30 

    31   for (int i = 0; i < 5; i++)

    32     block.LzmaProps[i] = sig[i];

    33   

    34   block.IsThereFilter = false;

    35   block.FilterMethod = 0;

    36 

    37   if (!CheckDictSize(sig + 1))

    38   {

    39     if (sig[0] > 1 || sig[1] > kMaxProp0Val)

    40       return S_FALSE;

    41     block.IsThereFilter = true;

    42     block.FilterMethod = sig[0];

    43     for (int i = 0; i < 5; i++)

    44       block.LzmaProps[i] = sig[i + 1];

    45     if (!CheckDictSize(block.LzmaProps + 1))

    46       return S_FALSE;

    47     RINOK(ReadStream_FALSE(inStream, sig + 5 + 8, 1));

    48   }

    49   UInt32 unpOffset = 5 + (block.IsThereFilter ? 1 : 0);

    50   block.UnpackSize = GetUi64(sig + unpOffset);

    51   if (block.HasUnpackSize() && block.UnpackSize >= ((UInt64)1 << 56))

    52     return S_FALSE;

    53   return S_OK;

    54 }

    55 

    56 }}
author	Robert McIntyre <rlm@mit.edu>
date	Sat, 03 Mar 2012 10:31:27 -0600
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