Goal

In order to support the transition to post-quantum crypto, it is required to be able to load multiple parallel sets of (cert,key) pairs, with varying cipher algorithms (RSA, ECC, MLDSA).

This requires an extension to the way  gtk-vnc locates  and loads certificates & keys.

Acceptance criteria

A list of verification conditions, successful functional tests, or expected outcomes in order to declare this story/task successfully completed.

• Configure a VNC client with RSA cert, check it can connect to VNC servers with any of  RSA-only, or RSA+MLDSA certs, and fails with MLDSA certs
• Configure a VNC client with MLDSA cert, check it can connect to VNC servers with any of  MLDSA-only, or RSA+MLDSA certs, and fails with RSA certs
• Configure a VNC client with RSA+MLDSA certs, check it can connect to VNC servers with any of  RSA-only, or MLDSA-only or RSA+MLDSA certs

Primary VNC server for testing should be QEMU