rsa - an old algorithm based on the difficulty of factoring
large numbers. A key size of at least 2048 bits is recommended for
RSA; 4096 bits is better. RSA is getting old and significant advances
are being made in factoring. Choosing a different algorithm may be
advisable. It is quite possible the RSA algorithm will become
practically breakable in the foreseeable future. All SSH clients
support this algorithm@suthakar$pwd
/home/oracle/.ssh
@suthakar$ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/oracle/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/oracle/.ssh/id_rsa.
Your public key has been saved in /home/oracle/.ssh/id_rsa.pub.
The key fingerprint is:
cd:3c:69:fa:b3:68:a6:6a:e0:63:eb:df:a5:4c:8c:4d oracle@suthakar.prince
The key's randomart image is:
+--[ RSA 2048]----+
| |
| |
| |
| + . |
| E S B |
| . = o . |
| . .. + o |
| + .+ ooo. |
| oo=o.=+. oo |
+-----------------+
@suthakar$pwd
@suthakar$ls -ltr
total 12
-rw-r--r--. 1 oracle oinstall 392 Feb 5 2018 known_hosts_org
-rw-r--r--. 1 oracle oinstall 404 Jun 11 21:52 id_rsa.pub
-rw-------. 1 oracle oinstall 1675 Jun 11 21:52 id_rsa
@suthakar$
you will see publickey and private key.
how to check the keylength
ssh-keygen -lf id_rsa.pub
2048 cd:3c:69:fa:b3:68:a6:6a:e0:63:eb:df:a5:4c:8c:4d id_rsa.pub (RSA)
@suthakar$
cat id_rsa.pub >>authorized_keys
@suthakar$ls -ltr
total 16
-rw-r--r--. 1 oracle oinstall 392 Feb 5 2018 known_hosts_org
-rw-r--r--. 1 oracle oinstall 404 Jun 11 21:52 id_rsa.pub
-rw-------. 1 oracle oinstall 1675 Jun 11 21:52 id_rsa
-rw-r--r--. 1 oracle oinstall 404 Jun 11 22:03 authorized_keys
scp authorized_keys username@xxxx :/user/home/oracle/.ssh/
