Certificate breaks when file is saved

[Dean Meyer]

We're having troubles with a certificate getting broken when a workbook is
saved.

Dean's PC: Running Excel 2007 in compatibility mode, we sign the VBA
project with a VeriSign certificate, and save the workbook as a .XLS file.
As long as we're in 2007 compatibility mode on this or other PCs, the
certificate behaves very nicely. We can save the file, re-open it and the
certificate works perfectly. [:~}

Old PC: We open that very-same signed .XLS workbook in Excel 2003, and the
certificate is respected (this time). We run no macros and make no edits.
We save the file and then close Excel. We re-open that workbook (still in
Excel 2003) and the certificate is broken -- doesn't match the code and
macros are disabled! [:~{

We then try opening that same workbook in 2007 compatibility mode, and
indeed the certificate is broken.

 

[JLGWhiz]

Was there a dealer warranty on that? <g>

 

[Dean Meyer]

Unfortunately, VeriSign only supports the installation of certificates, not
applications-level problems like this one.

 

[JLGWhiz]

I agree with royUK, saving the file as xl2003 format could be seen by the
digital cert as a change and that invalidates the cert. The companies that
sell the certs should be able to tell their consumers how the cert works with
respect to formats between versions,etc. What good is the cert if you can
only use it on the originating system?

 

[Dean Meyer]

At this point, here's what we think we've learned thanks to Michael Herzfeld,
Office Programmability Test Team:

* Adding/deleting worksheets within a workbook is construed as a change in
the project (since it adds/deletes objects) and breaks the certificate.

* Any change in ActiveX controls will break the certificate. We do dynamic
menues (changing menu item availability based on context) so that may also be
breaking the certificate. Not sure though.

* At this point we have no evidence either way that certtificates are not
portable between 2003 and 2007 compatibility mode.

It's not a VeriSign problem. Their certificate is behaving as it should.
The problem is the way Microsoft Office uses the certificate to protect far
more than just the code itself.

I don't see a work around.... Do you?

Thanks to all for pitching in.

--Dean