diff options
Diffstat (limited to 'src/md/runtime/mdfileformat.cpp')
| -rw-r--r-- | src/md/runtime/mdfileformat.cpp | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/src/md/runtime/mdfileformat.cpp b/src/md/runtime/mdfileformat.cpp new file mode 100644 index 0000000000..2edd2e0292 --- /dev/null +++ b/src/md/runtime/mdfileformat.cpp @@ -0,0 +1,195 @@ +// Licensed to the .NET Foundation under one or more agreements. +// The .NET Foundation licenses this file to you under the MIT license. +// See the LICENSE file in the project root for more information. +//***************************************************************************** +// MDFileFormat.cpp +// + +// +// This file contains a set of helpers to verify and read the file format. +// This code does not handle the paging of the data, or different types of +// I/O. See the StgTiggerStorage and StgIO code for this level of support. +// +//***************************************************************************** + +#include "stdafx.h" // Standard header file. +#include "mdfileformat.h" // The format helpers. +#include "posterror.h" // Error handling code. + +//***************************************************************************** +// Verify the signature at the front of the file to see what type it is. +//***************************************************************************** +#define STORAGE_MAGIC_OLD_SIG 0x2B4D4F43 // +MOC (old version of BSJB signature code:STORAGE_MAGIC_SIG) +HRESULT +MDFormat::VerifySignature( + PSTORAGESIGNATURE pSig, // The signature to check. + ULONG cbData) +{ + HRESULT hr = S_OK; + + // If signature didn't match, you shouldn't be here. + ULONG dwSignature = pSig->GetSignature(); + if (dwSignature == STORAGE_MAGIC_OLD_SIG) + { + Debug_ReportError("Invalid MetaData storage signature - old magic signature +MOC."); + return PostError(CLDB_E_FILE_OLDVER, 1, 0); + } + if (dwSignature != STORAGE_MAGIC_SIG) + { + Debug_ReportError("Invalid MetaData storage signature - unrecognized magic signature, should be BSJB."); + return PostError(CLDB_E_FILE_CORRUPT); + } + + // Check for overflow + ULONG lVersionString = pSig->GetVersionStringLength(); + ULONG sum = sizeof(STORAGESIGNATURE) + lVersionString; + if ((sum < sizeof(STORAGESIGNATURE)) || (sum < lVersionString)) + { + Debug_ReportError("Invalid MetaData storage signature - version string too long, integer overflow."); + return PostError(CLDB_E_FILE_CORRUPT); + } + + // Check for invalid version string size + if ((sizeof(STORAGESIGNATURE) + lVersionString) > cbData) + { + Debug_ReportError("Invalid MetaData storage signature - version string too long."); + return PostError(CLDB_E_FILE_CORRUPT); + } + + // Check that the version string is null terminated. This string + // is ANSI, so no double-null checks need to be made. + { + BYTE *pStart = &pSig->pVersion[0]; + BYTE *pEnd = pStart + lVersionString + 1; // Account for terminating NULL + BYTE *pCur; + + for (pCur = pStart; pCur < pEnd; pCur++) + { + if (*pCur == 0) + break; + } + + // If we got to the end without hitting a NULL, we have a bad version string + if (pCur == pEnd) + { + Debug_ReportError("Invalid MetaData storage signature - version string has not null-terminator."); + return PostError(CLDB_E_FILE_CORRUPT); + } + } + +#if !defined(FEATURE_METADATA_STANDALONE_WINRT) + // Only a specific version of the 0.x format is supported by this code + // in order to support the NT 5 beta clients which used this format. + if (pSig->GetMajorVer() == FILE_VER_MAJOR_v0) + { + if (pSig->GetMinorVer() < FILE_VER_MINOR_v0) + { + Debug_ReportError("Invalid MetaData storage signature - unrecognized version, should be 1.1."); + hr = CLDB_E_FILE_OLDVER; + } + } + else +#endif // !defined(FEATURE_METADATA_STANDALONE_WINRT) + // There is currently no code to migrate an old format of the 1.x. This + // would be added only under special circumstances. + if ((pSig->GetMajorVer() != FILE_VER_MAJOR) || (pSig->GetMinorVer() != FILE_VER_MINOR)) + { + Debug_ReportError("Invalid MetaData storage signature - unrecognized version, should be 1.1."); + hr = CLDB_E_FILE_OLDVER; + } + + if (FAILED(hr)) + hr = PostError(hr, (int)pSig->GetMajorVer(), (int)pSig->GetMinorVer()); + return hr; +} // MDFormat::VerifySignature + +//***************************************************************************** +// Skip over the header and find the actual stream data. +// It doesn't perform any checks for buffer overflow - use GetFirstStream_Verify +// instead. +//***************************************************************************** +PSTORAGESTREAM +MDFormat::GetFirstStream( + PSTORAGEHEADER pHeader, // Return copy of header struct. + const void *pvMd) // Pointer to the full file. +{ + const BYTE *pbMd; + + // Header data starts after signature. + pbMd = (const BYTE *) pvMd; + pbMd += sizeof(STORAGESIGNATURE); + pbMd += ((STORAGESIGNATURE*)pvMd)->GetVersionStringLength(); + PSTORAGEHEADER pHdr = (PSTORAGEHEADER) pbMd; + *pHeader = *pHdr; + pbMd += sizeof(STORAGEHEADER); + + // ECMA specifies that the flags field is "reserved, must be 0". + if (pHdr->GetFlags() != 0) + return NULL; + + // The pointer is now at the first stream in the list. + return ((PSTORAGESTREAM) pbMd); +} // MDFormat::GetFirstStream + +//***************************************************************************** +// Skip over the header and find the actual stream data. Secure version of +// GetFirstStream method. +// The header is supposed to be verified by VerifySignature. +// +// Returns pointer to the first stream (behind storage header) and the size of +// the remaining buffer in *pcbMd (could be 0). +// Returns NULL if there is not enough buffer for reading the headers. The *pcbMd +// could be changed if NULL returned. +// +// Caller has to check available buffer size before using the first stream. +//***************************************************************************** +PSTORAGESTREAM +MDFormat::GetFirstStream_Verify( + PSTORAGEHEADER pHeader, // Return copy of header struct. + const void *pvMd, // Pointer to the full file. + ULONG *pcbMd) // [in, out] Size of pvMd buffer (we don't want to read behind it) +{ + const BYTE *pbMd; + + // Header data starts after signature. + pbMd = (const BYTE *)pvMd; + // Check read buffer overflow + if (*pcbMd < sizeof(STORAGESIGNATURE)) + { + Debug_ReportError("Invalid MetaData - Storage signature doesn't fit."); + return NULL; + } + pbMd += sizeof(STORAGESIGNATURE); + *pcbMd -= sizeof(STORAGESIGNATURE); + + ULONG cbVersionString = ((STORAGESIGNATURE *)pvMd)->GetVersionStringLength(); + // Check read buffer overflow + if (*pcbMd < cbVersionString) + { + Debug_ReportError("Invalid MetaData storage signature - Version string doesn't fit."); + return NULL; + } + pbMd += cbVersionString; + *pcbMd -= cbVersionString; + + // Is there enough space for storage header? + if (*pcbMd < sizeof(STORAGEHEADER)) + { + Debug_ReportError("Invalid MetaData storage header - Storage header doesn't fit."); + return NULL; + } + PSTORAGEHEADER pHdr = (PSTORAGEHEADER) pbMd; + *pHeader = *pHdr; + pbMd += sizeof(STORAGEHEADER); + *pcbMd -= sizeof(STORAGEHEADER); + + // ECMA specifies that the flags field is "reserved, must be 0". + if (pHdr->GetFlags() != 0) + { + Debug_ReportError("Invalid MetaData storage header - Flags are not 0."); + return NULL; + } + + // The pointer is now at the first stream in the list. + return (PSTORAGESTREAM)pbMd; +} // MDFormat::GetFirstStream |