SSH - Remote Logon with Public Key

There a two different methods in order to configure a passwordless SSH logon on a remote HOME:

1. Create ssh key pair (private and public key) without password: e.g. ssh-keygen -b 4096 -t rsa -f [keyfile_name], type ENTER (empty passphrase)
2. Configure logon to your remote HOME: Login to remote account and add content of [public_keyfile].pub (be careful to choose the file ending in .pub and not the private keyfile!!!) to the content of ~/.ssh/authorized_keys
3. Please ensure that the folder ~./ssh and the file ~/.ssh/authorized_keys only have access rights for the owner (group and others should have no rwx)
4. Then you are ready to do remote ssh logon without password

1. Test if environment variables SSH_AGENT and SSH_AUTH_SOCK are defined; if not invoke a new ssh agent via eval $(ssh-agent)
2. Create ssh key pair (private and public key) with password: e.g. ssh-keygen -b 4096 -t rsa -f [private_keyfile], type a passphrase and hit ENTER
3. Add you private key to the ssh-agent: ssh-add [private_keyfile]
4. Configure logon to your remote HOME: Login to remote account and add content of [public_keyfile].pub (be careful to choose the file ending in .pub and not the private keyfile!!!) to the content of ~/.ssh/authorized_keys
5. Please ensure that the folder ~./ssh and the file ~/.ssh/authorized_keys only have access rights for the owner (group and others should have no rwx)
6. Then you are ready to do remote ssh logon without password
7. BTW: The ssh-agent can be locked by password (ssh-agent -x; then type your password) and unlocked (ssh-agent -X; then type your password)
8. Attention: The ssh-agent is not a permanent keystore! You have to add the private key manually for every new user session to the agent (e.g. on behalf of a script).