bug#31554: Fwd: Re: Potential bug in md5sum

[Riedy, Bill]

I believe I've found a bug in md5sum when it attempts to calculate on a 
hard linked file in NTFS on Windows 7.  Please read below for details.



-------- Forwarded Message --------
Subject:        Re: Potential bug in md5sum
Date:   Mon, 21 May 2018 19:22:32 +0200
From:   Mathias Michaelis <address@hidden>
To:     address@hidden



Hi Bill

md5sum is a part of the GNU coreutils package, 
http://www.gnu.org/software/coreutils/coreutils.html. It was ported by 
the gnuwin32 Project to Windows: 
http://gnuwin32.sourceforge.net/packages/coreutils.htm. The cause of the 
error you've reported is probably the fact the the gnuwin32 version of 
md5sum is from April 21, 2005.

I'm not the programmer neither of the original version nor of the ported 
one of md5sum and I have not any skills to change something on the 
current state of this tool.

I don't know if it helps but there is also a native windows solution out 
there:

https://support.microsoft.com/en-us/help/841290/availability-and-description-of-the-file-checksum-integrity-verifier-u

With best regards

Mathias


Am 21.05.2018 um 14:50 schrieb address@hidden:
> Mathias, I'm not sure if your package contains md5sum, but I've been 
> looking for a way to get in touch with that packages owner. md5sum 
> appears to have an issue with hard links in NTFS on Windows 7. md5sum 
> appears to be creating a value from the hardlink itself, not following 
> the link to the "real" file. An example of this is calc.exe found in 
> c:\windows\system32. I've included a line of powershell to get this 
> information.
>
> get-childitem c:\windows\system32\calc.exe | format-list fullname, target
>
> FullName : C:\windows\system32\calc.exe
> Target : 
> {C:\Windows\winsxs\amd64_microsoft-windows-calc_31bf3856ad364e35_6.1.7600.16385_none_05b2f2e2346cfea4\calc.exe}
>
> md5sum (get-childitem c:\windows\system32\calc.exe | select-object 
> -expand fullname)
> \60b7c0fead45f2066e5b805a91f4f0fc *C:\windows\system32\calc.exe
>
> md5sum (get-childitem c:\windows\system32\calc.exe | select-object 
> -expand target)
> \10e4a1d2132ccb5c6759f038cdb6f3c9 
> *C:\Windows\winsxs\amd64_microsoft-windows-calc_31bf3856ad364e35_6.1.7600.16385_none_05b2f2e2346cfea4\calc.exe
>
> If I copy calc.exe to c:\temp and run the md5sum against that file I 
> get the value that begins with '10e4'
>
> copy-item c:\windows\system32\calc.exe c:\temp -force
>
> md5sum c:\temp\calc.exe
> \10e4a1d2132ccb5c6759f038cdb6f3c9 *c:\temp\calc.exe
>
> If you are not the appropriate person (which is likely) would you 
> happen to know who I can forward this information to? Thanks for any 
> help you can provide.
>
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