FreeBSD server setup steps »sshd configuration (DSA authentication)

sshd configuration (DSA authentication)

Posted by: admin at 11 Monday 8th, 2008

FreeBSD sshd is by default to boot.

 # which sshd
/usr/sbin/sshd

So, after the /etc/ssh/sshd_config to AllowUsers USERNAME only that, BURUTOFOSUATAKKU (brute force attacks) against the DSA should be authenticated.
If you look you see the access log, or the humble country crackers or分RIMASEN bots, you should find that traces of the attack.

Rewrite of the configuration file

/etc/ssh/sshd_config

 Protocol 2

SSH2 protocol used

 PermitRootLogin no

disable root login in

 PubkeyAuthentication yes

Authentication Using DSA

 PasswordAuthentication no
PermitEmptyPasswords no

No and no and no password authentication and password

 ChallengeResponseAuthentication no

So no to no the password on it.

After rewriting sshd restart.

 # /etc/rc.d/sshd restart

Or, in earlier versions may also be an error because, if it is in the following way.

 # ps aux | grep sshd
# kill -HUP  PID

Private key `id_dsa` and public key `id_dsa.pub` to generate

 $ ssh-keygen -d

 Generating public/private dsa key pair.
Enter file in which to save the key (/home/ USERNAME /.ssh/id_dsa):    [Enter] 
Created directory '/home/ USERNAME /.ssh'.
Enter passphrase (empty for no passphrase):                      [PASSWORD] [Enter] 
Enter same passphrase again:                                     [Re PASSWORD] [Enter] 
Your identification has been saved in /home/ USERNAME /.ssh/id_dsa.
Your public key has been saved in /home/ USERNAME /.ssh/id_dsa.pub.
The key fingerprint is:
xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx  USERNAME @ HOST . DOMAIN . NAME

Public key `id_dsa.pub` to rename the

 $ cd /home/ USERNAME /.ssh
$ mv id_dsa.pub authorized_keys
$ chmod 0600 authorized_keys

Private key `id_dsa` to move to a client machine

ssh client to connect to the /home/ USERNAME /.ssh/id_dsa move. If you are concerned about security, FTP, etc. There is no USB floppy disk is a good memory and do in the process of using the media attention.
id_dsa to save the file, it will depend on the client terminal, please refer to your manual.
Personally open source Tera Term is a good idea.

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