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| author | Mounir IDRASSI <mounir.idrassi@idrix.fr> | 2019-11-26 09:55:56 +0100 |
|---|---|---|
| committer | Mounir IDRASSI <mounir.idrassi@idrix.fr> | 2019-11-27 00:15:43 +0100 |
| commit | 79eea6e5b1fd1300729d31b7ccda6a4718b4b81b (patch) | |
| tree | 0854c74d26e0fe63d2d573de168bd0adb922b8ec | |
| parent | 9741c9209d0deedcc5d60434e5e7df3c531ff192 (diff) | |
| download | VeraCrypt-79eea6e5b1fd1300729d31b7ccda6a4718b4b81b.tar.gz VeraCrypt-79eea6e5b1fd1300729d31b7ccda6a4718b4b81b.zip | |
Windows: Don't restore MBR to VeraCrypt value if it is coming from a loader different from us or different from Microsoft one.
| -rw-r--r-- | src/Common/BootEncryption.cpp | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/src/Common/BootEncryption.cpp b/src/Common/BootEncryption.cpp index 3ad7320c..ccf3ac2f 100644 --- a/src/Common/BootEncryption.cpp +++ b/src/Common/BootEncryption.cpp @@ -275,6 +275,27 @@ bool ZipAdd (zip_t *z, const char* name, const unsigned char* pbData, DWORD cbDa return true; } +static BOOL IsWindowsMBR (const byte *buffer, size_t bufferSize) +{ + BOOL bRet = FALSE; + byte g_pbMsSignature[4] = {0x33, 0xc0, 0x8e, 0xd0}; + const char* g_szStr1 = "Invalid partition table"; + const char* g_szStr2 = "Error loading operating system"; + const char* g_szStr3 = "Missing operating system"; + + if ((0 == memcmp (buffer, g_pbMsSignature, 4)) && + (BufferContainsString (buffer, bufferSize, g_szStr1) + || BufferContainsString (buffer, bufferSize, g_szStr2) + || BufferContainsString (buffer, bufferSize, g_szStr3) + ) + ) + { + bRet = TRUE; + } + + return bRet; +} + namespace VeraCrypt { #if !defined (SETUP) @@ -3546,8 +3567,10 @@ namespace VeraCrypt } } - // perform actual write only if content is different - if (memcmp (mbr, bootLoaderBuf, TC_MAX_MBR_BOOT_CODE_SIZE)) + // perform actual write only if content is different and either we are not in PostOOBE mode or the MBR contains VeraCrypt/Windows signature. + // this last check is done to avoid interfering with multi-boot configuration where MBR belongs to a boot manager like Grub + if (memcmp (mbr, bootLoaderBuf, TC_MAX_MBR_BOOT_CODE_SIZE) + && (!PostOOBEMode || BufferContainsString (mbr, sizeof (mbr), TC_APP_NAME) || IsWindowsMBR (mbr, sizeof (mbr)))) { memcpy (mbr, bootLoaderBuf, TC_MAX_MBR_BOOT_CODE_SIZE); |