VC+ built EXE and DLL have inconsistent CRCs

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jangs2458 - 09 Jun 2004 00:36 GMT

Using Visual Studio we found when you rebuild an EXE file, even if a few minutes later, each time the CRC is different
Same with DLL files

I heard that if you skip a certain number of bytes in the beginning and end of the file, you can get consistent CRC signatures. Anyone knows which bytes to skip

Am open to other suggestions for EXE and DLL authenication

Thanks

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Carl Daniel [VC++ MVP] - 09 Jun 2004 00:50 GMT

> Using Visual Studio we found when you rebuild an EXE file, even if a
> few minutes later, each time the CRC is different.
[quoted text clipped - 5 lines]
>
> Am open to other suggestions for EXE and DLL authenication.

There's a timestamp in the PE header at offste 0xE4 into the file (typical -
you actually need to read the EXE header & skip the stub to find the PE
header in general).

See
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dndebug/html/ms
dn_peeringpe.asp
for a discussion of the PE headers & how to interpret them.

-cd

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