This bug is similar to bug 4436. When using public key authentication, it would be nice if we could use keys held in a running ssh-agent. As far as I can tell, this does not work, since we are clearing SSH_AUTH_SOCK regardless of authentication type.
https://community.thinlinc.com/t/using-ssh-key-agents-with-the-thinlinc-client/444
Another benefit of this would be the ability to use GPG sub-keys to authenticate with ThinLinc via gpg-agent. gpg-agent supports ssh-agent emulation, so in theory we should get this feature "on the house". Extracting a GPG sub-key in SSH format is non-trivial these days, so those who use gpg-agent for SSH authentication will have a hard time using the same key with ThinLinc.
*** Bug 8233 has been marked as a duplicate of this bug. ***
macOS apparently has the weird setup where the key is still stored on disk, but the passphrase for it is stored in the keychain: https://apple.stackexchange.com/questions/48502/how-can-i-permanently-add-my-ssh-private-key-to-keychain-so-it-is-automatically I am not sure if that's within scope here or not.
Created attachment 1198 [details] Mockup 1 - the tlclient login window when public key auth is used
Created attachment 1199 [details] Mockup 2 - the tlclient security options
Created attachment 1200 [details] Mockup 3 - the tlclient options public key details window
Created attachment 1201 [details] Mockup 4 - the tlclient public key file chooser
The idea depicted in the attached tlclient mockup images is as follows: Instead of the user being required to pick a single key file to use for public key auth, he or she should be able to configure a list of keys in the options. Furthermore, ssh-agent should also be available. Once connecting, tlclient will test each manually configured key as well as keys held in ssh-agent. 1. When public key auth is chosen, the login window no longer shows widgets for choosing a key (attachment 1198 [details]). 2. The security options page now shows a detail button next to the "Public key" authentication method (attachment 1199 [details]). 3. The public key details window allows the user to add or remove private key files to use, and to toggle the use of ssh-agent (attachment 1200 [details]). 4. After pressing "Add" for a new private key file, a file chooser is opened (attachment 1201 [details]).
