I have configured Putty to run with Yubikey for SSH connections following procedure here. I have configured remote server to accept only key connection. Everything was working as expected.
After Windows 10 restart, set-up was broken. Symptom: Connection error on remote server (Putty not using the correct authentication method). Cause: gpg-agent not running
I solved the issue by running C:\>gpg-connect-agent KILLAGENT /bye with result:
gpg-connect-agent: no running gpg-agent - starting 'C:\\Program Files (x86)\\Gpg4win\\..\\GnuPG\\bin\\gpg-agent.exe'
gpg-connect-agent: waiting for the agent to come up ... (5s)
gpg-connect-agent: connection to the agent established
OK closing connection
Putty was then choosing the correct authentication method and reading the Yubikey.
Why did this happen? Will I need to run KILLLAGENT after every windows restart? or am I missing some other configuration?
Edit:
I have done other system restarts since then and similar issues occurred. Launching Kleopatra before Putty enables the use of the key with Putty as well as running KILLAGENT.
How to ensure pgp-agent loads correctly at startup?
