Karhu requires that keys be setup manually such that no passwords need to be typed when Karhu does SSH operations; Karhu itself does not store any passwords.

Direct SSH access

You need to be able to connect to the remote PC at all, without typing a password, to begin with. Set your target PC up to allow one to SSH into it, set up keys and then use ssh-copy-id. More information here:

https://serverfault.com/questions/241588/how-to-automate-ssh-login-with-password

Bitbucket

For the repository holding your remote project the PC you SSH into needs to have passwordless repo access in case you want to apply git operations, which is most easily done by following these instructions:

https://confluence.atlassian.com/bitbucket/set-up-ssh-for-git-728138079.html

For this to work over SSH you then need to make sure the password is stored between sessions so that new SSH sessions don't need to type it. Start ssh-agent, ssh-add -k ~/.ssh/id_rsa and finally add the following to your .bash_profile so that it gets called on startup:

#!
keychain ~/.ssh/id_rsa
. ~/.keychain/<PC name>-sh

Just replace <PC name> with your PC's name. The easiest thing to do is to call keychain manually one time first and see what files end up in the .keychain/ directory.