How to key-based authentication for SSH session

[Ageek]

SSH and key based authentication

OpenSSH was invented by the openBSD developers and now with default installation the openSSH client is installed. Server key are (private/ public) generated at the installation.

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	ls /etc/ssh

	ssh_configd	-> client config file
	sshd_config 	-> server config file
	ssh_host_rsa_key.pub 	-> RSA server public key
	ssh_host_rsa_key		-> RSA server private key

user specific ssh configuration is stored in ~/.ssh

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~/.ssh/known_host		-> server public keys
 ~/.ssh/autherized_key		-> user public keys

Example :

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ssh username@hostname/ip
ssh username@hostname/ip ls /tmp 
ssh -p 1500 username@hostname/ip

Authentication with keys

Create key pair

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# ssh_keygen -t rsa

Copy the keys to the remote server

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ssh_copy_id -i ~/.ssh/id_rsa.pub root@host/ip

Connect to the server without password

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ssh root@host/ip cat /root/.ssh/autherized.key

Secure Copy Protocol (SCP)


Copy the files securely over the ssh tunnel.

Examples:

Copy local file to a remote server

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scp /home/user/lab.txt root@host/ip:

Copy remote file to local machine

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scp -P 1500 root@host/ip:/home/user/lab.txt /home

[Neo]

Fantastic !!! Very useful article. REP+