Difference between revisions of "Ssh simple explanation"
From Finninday
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===Moving pieces=== | ===Moving pieces=== | ||
| + | * ssh-agent : this is client software that can hold credentials for use when connecting to remote hosts, allowing passwordless entry. Use looks like: <tt>ssh-agent bash</tt> then <tt>ssh-add</tt>. Often, X sessions can be used as the ssh-agent and configured to prompt when it needs to perform an ssh-add. | ||
* private key : generate this with <tt>ssh-keygen</tt>. It must have 0600 permissions and usually lives in ~/.ssh | * private key : generate this with <tt>ssh-keygen</tt>. It must have 0600 permissions and usually lives in ~/.ssh | ||
* public key : generate this with <tt>ssh-keygen</tt>. It must have 0600 permissions and usually lives in ~/.ssh. This file should be distributed to remote hosts and placed in the authorized keys files to allow ssh access to that remote host. | * public key : generate this with <tt>ssh-keygen</tt>. It must have 0600 permissions and usually lives in ~/.ssh. This file should be distributed to remote hosts and placed in the authorized keys files to allow ssh access to that remote host. | ||
Revision as of 23:28, 3 May 2011
No matter how many times I configure ssh keys, I rarely have the process go smoothly. It is time to write down how it works so I can get it straight in my head.
Moving pieces
- ssh-agent : this is client software that can hold credentials for use when connecting to remote hosts, allowing passwordless entry. Use looks like: ssh-agent bash then ssh-add. Often, X sessions can be used as the ssh-agent and configured to prompt when it needs to perform an ssh-add.
- private key : generate this with ssh-keygen. It must have 0600 permissions and usually lives in ~/.ssh
- public key : generate this with ssh-keygen. It must have 0600 permissions and usually lives in ~/.ssh. This file should be distributed to remote hosts and placed in the authorized keys files to allow ssh access to that remote host.
- authorized keys file : this is a list of users and hosts that have access via ssh to this account
- known hosts file : a list of hosts that have been visited and thus authorized
ssh without passwords for cron
A special private key can be generated without a passphrase. Distribute the public key as normal, but when issuing the ssh command in a script, include the identity (private key) without a passphrase:
ssh -i /home/rday/.ssh/cronkey <remote machine> command
There, that wasn't so hard.
