Ssh-Agent

When the SSH agent is running, the ssh-add command can be used to load a SSH key. The SSH agent then will request a password when needed, and load the key details in memory. Adding the SSH key just requires the path to the private key. ssh-add ~/.ssh/id_ed25519 When the key is loaded, use the -l or -L option to show the identities that the SSH agent has. ssh-add -l

The ProxyJump defines a bastion host (jump host, jump server, jump box) to use. Values Value Meaning none Disable ProxyJump functionality HOST Define the hostname of the bastion host [USER]HOST[:PORT] Define one or more parameters of the bastion host URI Define parameters in URI format Hostname Format: hostname User Format: user@hostname Port Format: hostname:port Command-line usage ssh -J bastion destinationsystem These parameters can also be specified in the format as a URI .

The ForwardAgent option specifies if SSH agent forwarding is allowed or not. ForwardAgent values Value Meaning Yes Agent forwarding is allowed No (default) Agent forwarding is not allowed PATH Path to the agent socket $VARIABLE Environment variable that stores the path Security caution Agent forwarding should not be used if not strictly needed. Any user that can access the agent’s socket stored in SSH_AUTH_SOCK may have access through the forwarded connection.

The agent forwarding feature in SSH allows using your local SSH agent to be reached through an existing SSH connection. This way you don’t have to store copies of your private keys on intermediate systems to use them for authentication. While SSH agent forward simplifies things, it also introduces a new risk related to Unix domain socket. If a user on the intermediate system can access the related socket, then it may abuse this connection back to the SSH agent to authenticate on your behalf.

The ssh-agent command is started manually using eval $(ssh-agent). This will initiate the SSH agent and make it available for clients, such as ssh, to use it. To confirm that the agent is running is by looking at the SSH_AUTH_SOCK environment variable. Automatic start of SSH agent Gnome Keyring SSH Agent When using Gnome, it typically comes with its SSH agent as part of Keyring. This will automatically load any files in ~/.

The ssh-agent command starts the SSH agent, a helper utility to store private keys when using public key authentication. The ssh-agent process is usually started at the the beginning of a login session and then can be connected to by a SSH client. Clients can detect the environment variable named SSH_AUTH_SOCK. Related settings on the client IdentityAgent

Disable usage of SSH agent identities