- Enable ssh-agent transparently and pervasively in Mac OS X Lion/Mountain Lion - README.md.
- Enable SSH for the Database Agent. For Linux hosts only. Applies only when Database Agent is running on a Linux host.
- Ssh-add program usage with ssh-agent and SSH keys. How to enable SSH public key authentication and single sign-on.
Verify you can connect to the SSH host by running the following command from a terminal / PowerShell window replacing [email protected] as appropriate. Ssh [email protected] # Or for Windows when using a domain / AAD account ssh [email protected]@hostname. Ssh-add is a command for adding SSH private keys into the SSH authentication agent for implementing single sign-on with SSH.The agent process is called ssh-agent; see that page to see how to run it. The cool thing about ssh-agent and ssh-add is that they allow the user to use any number of servers, spread across any number of organizations, without having to type in a password every time when.
SSH-agent remembers SSH Public Key authentication, which can be time-limited by the user.This avoids the user having to type the password for each SSH connection, especially relevant to using Git over SSH.Native Windows has SSH including SSH-agent, and separately WSL also can use SSH-agent.SSH-agent works well withGit over SSH.
Add SSH keys to SSH-agent
To use SSH-agent, add SSH keys like:
- remember authentication for a period of time (here, 30 minutes)
One can optionally remove all SSH-agent keys from RAM by
Note that if the SSH private key was manually deleted, access to the remote SSH server is lost until a new private key is placed on the remote server when an SSH key is removed from SSH-agent.
Each operating system has a distinct method of enabling SSH-agent, as follows.
Windows SSH-agentis off by default, but can be enabled from PowerShell:
The status of Windows SSH-agent can be checked from PowerShell: Mistborn secret history pdf free download.
if status is “Running” then SSH-agent should be working.
Linux / WSL
This works for Linux in general, including Windows Subsystem for Linux.
- Windows SSH-agent vulnerabilities
- Linux SSH-agent vulnerabilities
Since gpg-agent isn't used for ssh authentication on Ubuntu, and there are indeed 2 different daemons vying for the job, it can get complicated to figure out how to untangle the distro and step the agent into his rightful position.
Enable Ssh Agent Ubuntu
This is simple once you know exactly which knobs to frob; in this case there are 3:
- Tell Xsession initialization to not start ssh-agent
- Tell Gnome init not to start the gnome keyring
- Enable ssh agent emulation support on gpg-agent
Using gpg for encryption on Linux is an important way to store PKI keys in hardware-backed security modules like a Yubikey, or a more traditional smartcard. Using an agent is also an important way to securely make the authentication process more convenient.
After installing gnupg, the gpg-agent daemon (among others), tooling, and libraries will be on your system. These changes will bring that agent online for use. If you have your keys created, you've probably already installed the package. If not, there are plenty of great guides describing the process.
Enable Ssh Agent Portal
Allowing the ssh-agent daemon to run will interfere with running gpg-agent and its ssh agent capability.
Edit this file to change the line
This system is inherited from Debian (on which Ubuntu is based), where while looking for a good place to start the venerable ssh-agent daemon, the maintainers decided 'during the X session initialization itself' would fit nicely. Changing that config option signals the initialization process to skip that step.
This file starts the gnome keyring, which will also interfere with gpg-agent.
Make a copy of this file to
~/.config/autostart/gnome-keyring-ssh.desktop and add a line
Hidden=true to disable this autostart for your user account only.
Create this if it doesn't exist, and add the line
Enable Ssh Agent Access
Besides the agent and tools, the gnupg installation process also installs systemctl user units to manage these daemons via systemctl (see
$ systemctl --user status gpg-agent will show the status of gpg-agent, while
$ systemctl --user reload gpg-agent can be used to have the daemon reload config changes.
There is also a unit
gpg-agent-ssh.socket which creates and mediates connections to the gpg-agent socket which speaks like ssh-agent. This means that the socket is always created, but the above setting causes the agent to listen on the socket and the
SSH_AUTH_SOCK environment variable–which ssh tools use to find the socket–to be appropriately set.
Since these daemons all get setup during the start of your login, simply log out of your X session and log back in to have everything working right without a restart (often ctrl-alt-backspace in gnome or mod+shift+e by default in i3wm).
ssh-add -l to see if your gpg keys are now available for ssh authentication.
Enable Ssh In Linux
A lot of other instructions out there have old or unnecessary steps, I found this was sufficient to get the setup working correctly.