Hi everybody,
well I got it working - thanks to JBs for commenting the field
positions in ImageReader.
In case anybody needs the same really urgently it may be helpfull so I
am posting it here:
Addtional code in class ModuleDefinition:
public int TimeDateStampPosition { get { return
Image.TimeDateStampPosition; } }
public int FileChecksumPosition { get { return
Image.FileChecksumPosition; } }
public string GetBuildIndependentHash()
{
var byteArray = File.ReadAllBytes(Image.FileName);
//overwrite parts of the assembly file content byte array
//(only in memory of course) that change on every build
with
//an empty bytearray and thus make it compareable
var guidSection = Image.GuidHeap.Section;
var empty = new byte[guidSection.SizeOfRawData];
Buffer.BlockCopy(empty, 0, byteArray,
TimeDateStampPosition, 4);
Buffer.BlockCopy(empty, 0, byteArray,
FileChecksumPosition, 4);
//MVID
Buffer.BlockCopy(empty, 0, byteArray,
(int) guidSection.PointerToRawData, (int)
guidSection.SizeOfRawData);
var md5 = new MD5CryptoServiceProvider();
var result = md5.ComputeHash(byteArray);
var sb = new StringBuilder();
for (var i = 0; i < result.Length; i++)
sb.Append(result[i].ToString("X2"));
return sb.ToString();
}
The int field TimeDateStampPosition was added to the Image class and
filled in the ReadImage() method of ImageReader (right above the //
TimeDateStamp comment) using the following line:
image.TimeDateStampPosition = (int) BaseStream.Position;
Also the int field FileChecksumPosition was added to the Image class
and filled in method ReadOptionalHeaders() of class ImageReader. The
line stands under under the Advance(66); statement (which follows
the // FileChecksum comment) and looks like this:
image.FileChecksumPosition = (int) (BaseStream.Position-4);
For my requirements this works good enough but I would of course be
interested about your thoughts about this, JB.
Best regards
Florian
On 18 Jun., 23:07, Greg Young <[email protected]> wrote:
> I could use this code as well
>
> On 18 Jun 2011 16:30, "Florian" <[email protected]> wrote:
> Well as it seems, the locations of TimeDateStamp and FileChecksum are
> quite easy to find. Their positions can be found in the DOSHeader and
> in PEOptionalHeader, the first two headers read from a assembly file
> (looked the code up in Mono.Cecil.PE.ImageReader.ReadImage()).
> Unfortunately locating the position of MVID is more complicated.
>
> I am not quite sure what to do. Changing the sourcecode of ImageReader
> on my local machine to save the byte positions of those three fields
> would be the easiest thing to do. This way I could later on build a
> file hash that ignores these fields and reuse the filehash on
> different dlls / exes built on the same sources to get them compared.
>
> But of course every time the next Mono.Cecil version is released I
> would have to do the same changes again and again.
>
> @JB: Would you bother including such a hashing method in the
> Mono.Cecil sources if I can provide you a proper implementation that
> meets your quality expectations? I guess the requirement I have there
> would also be present for other people, for example for working with
> continuous integration build systems.
>
> Best Regards Florian
>
> On 18 Jun., 15:57, Florian <[email protected]> wrote:
>
> > Hi Alex,
>
> > thanks for the pointer, I didnt k...
> > > - Zitierten Text anzeigen -- Zitierten Text ausblenden -
>
> > - Zitierten Text anzeigen -
>
> --
> --
> mono-cecil
--
--
mono-cecil
