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SSH keys

Read access to .ssh

Having read access over the .ssh directory for a specific user, we may read their private ssh keys found in /home/user/.ssh/id_rsa or /root/.ssh/id_rsa, and we can copy it to our machine and use the -i flag to log in with it:

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vim id_rsa
chmod 600 id_rsa
# If ssh keys have lax permissions, i.e., maybe read by other people, the ssh server would prevent them from working.
ssh user@10.10.10.10 -i id_rsa

Write access to .ssh

Having write access over the .ssh directory for a specific user, we may place our public key in /home/user/.ssh/authorized_keys.

But for this we need to have gained access first as that user. With this technique we obtain ssh access to the machine. 

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# Generating a public private rsa key pair
ssh-keygen -f key

This will give us two files: key (which we will use with ssh -i) and key.pub, which we will copy to the remote machine.

Let us copy key.pub, then on the remote machine, we will add it into /root/.ssh/authorized_keys:

Last update: 2024-06-06
Created: May 23, 2023 19:56:20