sign RDP file with timestamp

Hi,

after installing the April 2026 update, our customers experience warning messages when using RDP files to connect to their servers hosted by us.

We need to sign the RDP files. But we need to include a timestamp, so the signature stays valid after certificate expiration.

rdpsign.exe does not support timestamping. Set-AuthenticodeSignature is unable to access the private key of our code signing certificate which is stored on a HSM. signtool.exe does not support RDP files.

What is the recommended procedure in this case?

Thank you!