diff options
Diffstat (limited to 'CPP/7zip/Archive/Lzma/LzmaIn.cpp')
-rwxr-xr-x | CPP/7zip/Archive/Lzma/LzmaIn.cpp | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/CPP/7zip/Archive/Lzma/LzmaIn.cpp b/CPP/7zip/Archive/Lzma/LzmaIn.cpp new file mode 100755 index 00000000..342b01e1 --- /dev/null +++ b/CPP/7zip/Archive/Lzma/LzmaIn.cpp @@ -0,0 +1,56 @@ +// Archive/LzmaIn.cpp + +#include "StdAfx.h" + +#include "LzmaIn.h" + +#include "../../Common/StreamUtils.h" + +namespace NArchive { +namespace NLzma { + +static bool CheckDictSize(const Byte *p) +{ + UInt32 dicSize = GetUi32(p); + int i; + for (i = 1; i <= 30; i++) + if (dicSize == ((UInt32)2 << i) || dicSize == ((UInt32)3 << i)) + return true; + return false; +} + +HRESULT ReadStreamHeader(ISequentialInStream *inStream, CHeader &block) +{ + Byte sig[5 + 9]; + RINOK(ReadStream_FALSE(inStream, sig, 5 + 8)); + + const Byte kMaxProp0Val = 5 * 5 * 9 - 1; + if (sig[0] > kMaxProp0Val) + return S_FALSE; + + for (int i = 0; i < 5; i++) + block.LzmaProps[i] = sig[i]; + + block.IsThereFilter = false; + block.FilterMethod = 0; + + if (!CheckDictSize(sig + 1)) + { + if (sig[0] > 1 || sig[1] > kMaxProp0Val) + return S_FALSE; + block.IsThereFilter = true; + block.FilterMethod = sig[0]; + for (int i = 0; i < 5; i++) + block.LzmaProps[i] = sig[i + 1]; + if (!CheckDictSize(block.LzmaProps + 1)) + return S_FALSE; + RINOK(ReadStream_FALSE(inStream, sig + 5 + 8, 1)); + } + UInt32 unpOffset = 5 + (block.IsThereFilter ? 1 : 0); + block.UnpackSize = GetUi64(sig + unpOffset); + if (block.HasUnpackSize() && block.UnpackSize >= ((UInt64)1 << 56)) + return S_FALSE; + return S_OK; +} + +}} |