File Verification 1

[deltarho]

I've just finished a small project which in principle is similar to the System File Checker. Instead of using CRC32, as does SFC, I've implemented the MD5 hashing algorithm to create a signature for a pre-defined list of files. The file paths and signatures are held in the registry and on a Restart/Shutdown the current files have their signature computed and are compared with those in the registry. If any signatures fail a match we can abort the Restart/Shutdown and investigate.

At the moment the list is:

C:\WINDOWS\System.ini
C:\WINDOWS\win.ini
C:\AUTOEXEC.BAT
C:\CONFIG.SYS
C:\MSDOS.SYS
C:\WINDOWS\PROTOCOL.INI
C:\WINDOWS\Application Data\Microsoft\Templates\Normal.dot
C:\WINDOWS\SYSTEM\msconfig.exe
C:\WINDOWS\SYSTEM\VMM32.VXD
c:\windows\fonts\desktop.ini
C:\WINDOWS\SYSTEM\FONTEXT.DLL
C:\WINDOWS\HIMEM.SYS
C:\WINDOWS\WIN.COM
C:\DOSSTART.BAT
C:\IO.SYS
C:\WINDOWS\RUNDLL32.EXE

The time taken to verify the above is less than 200ms on my 600MHz system.

Obviously, many files can bring us grief during a boot but I've simply included those which I've seen mentioned on forums, at MSKB and some I reckoned myself.

System.ini and Win.ini are not carved in stone so we will be alerted on innocuous alterations. I can live with that after seeing a member of another forum find that she had a corrupted System.ini and all copys in the rb0nn.cab files were also corrupted.

Can anyone think of any other files to include in this 'critical' list.

Thanks in anticpation

deltarho