Signing office COM Add-in

Question

I've developed an extension based on NetOffice. My office configuration requires applications to be signed by Trusted Publishers. I tried signing the output DLL with signtool.exe, with a valid certificate, but unfortunately, Office says "There is no digital signature available".

The option can be enabled via:

File → Options → Trust Center → Trust Center Settings → Add-ins → Require application Add-ins to be signed by Trusted Publisher

What's the appropriate method for signing the DLL?

When using VSTO, ClickOnce handles the signing, also there's a .manifest file that is created for the DLL, I'm not sure if its required or not but I'm unable to create one for my class library.

Some info that I found online:

• https://msdn.microsoft.com/en-us/library/bb772096(v=vs.120).aspx

• https://msdn.microsoft.com/en-us/library/bb386179.aspx

• https://msdn.microsoft.com/en-us/library/che5h906.aspx

Answer 1

First, create a .pfx file with pvk2pfx.exe:

• "C:{PATH}\pvk2pfx.exe" -pvk {PVK FILE NAME} -pi {cert owner name} -spc {SPC FILE NAME} -pfx {PFX FILE NAME}
• e.g.: "C:\Program Files\Microsoft SDKs\Windows\v7.1\Bin\pvk2pfx.exe" -pvk mypvkfile.pvk -pi companyname -spc myspcfile.spc -pfx mypfxfile.pfx

Then use the SignTool.exe utility:

• signtool sign /f "C:{PATH}\mypfxfile.pfx" /p {cert owner name} "C:{PATH}\setup.exe"