KB978601 causes « invalid digital signature » error with a CAB file – Windows Heads

KB978601 causes « invalid digital signature » error with a CAB file

paul — Fri, 28 Feb 2020 05:07:45 +0000

Customers with KB978601 installed are unable install one of our
software products. They get the error « invalid digital signature » when
the installer reaches the last cab file. I was able to reproduce the
problem on Windows 7 and XP (both with the latest updates), and also
verified the problem goes away after uninstalling KB978601.

The following error message was logged: « Error 1330. A file that is
required cannot be installed because the cabinet file setup11.cab has
an invalid digital signature. This may indicate that the cabinet file
is corrupt. Error 24592 was returned by WinVerifyTrust. »

Our product comes with 11 cab files. Only the last one gives the
error. When you right-click on the cab file and view the certificate,
the message is « This digital signature is not valid. »

This problem just started happening yesterday (4/15/10).

Any ideas or similar experiences?

Répondre à : KB978601 causes « invalid digital signature » error with a CAB file

paul — Fri, 28 Feb 2020 05:08:10 +0000

Is the digital signature valid?

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Répondre à : KB978601 causes « invalid digital signature » error with a CAB file

paul — Fri, 28 Feb 2020 05:08:17 +0000

I’d hazard a guess that the file will need to be resigned. Update KB978601
changes the way in which cabinet and executable files are signed; I’m not expert
in this area, but from my interpretation of it this change will invalidate
previously good signatures under certain circumstances.

You might get better advice in microsoft.public.security.crypto.

Harry.

Répondre à : KB978601 causes « invalid digital signature » error with a CAB file

paul — Fri, 28 Feb 2020 05:08:26 +0000

We’ve run into this issue with KB978601 also.

The key issue here is that MS stepped up enforcement in the signature validation subsystem in such a way that previously valid signatures now don’t validate.

It’s a simple test:
1. Uninstall KB978601
2. Validate the signature (look in file properties). It’s okay.
3. Install KB978601
4. Validate the signature again. Now it’s invalid. Same file. Nothing changed except for WinTrust.dll (the core Authenticode DLL in Windows that is updated by KB978601).

For our situation, the cab files that fail post-KB978601 validation are all similar: they all contain only 1 zero-length file. So essentially these cabs are empty (just a file list with no real contents). As soon as we put some dummy data in the cab file (20 characters in our case), the signature validated just fine.