Which two are true?

User jack logs in to host solaris and then attempts to log in to host oracle using ssh. He receives
the following error message:
The authenticity of host oracle (192.168.1.22) can’t be established. RSA key fingerprint is
3B:23:a5:6d:ad:a5:76:83:9c:c3:c4:55:a5:18:98:a6
Are you sure you want to continue connecting (yes/no)?
Which two are true?

User jack logs in to host solaris and then attempts to log in to host oracle using ssh. He receives
the following error message:
The authenticity of host oracle (192.168.1.22) can’t be established. RSA key fingerprint is
3B:23:a5:6d:ad:a5:76:83:9c:c3:c4:55:a5:18:98:a6
Are you sure you want to continue connecting (yes/no)?
Which two are true?

A.
The public host key supplied by solaria is not known to the host oracle.

B.
The error would not occur if the RSA key fingerprint shown in the error message was added to
the /etc/ssh/known_hosts file on solaris.

C.
The private host key supplied by oracle is not known to solaris.

D.
If jack answers yes, the RSA public key for the host oracle will be added to the known_hosts file
for the user jack.

E.
The public host key supplied by oracle is not known to the host solaris.

Explanation:
The fingerprints are used to guard against man in the middle attacks. Since ssh
logins usually work over the internet (an insecure connection), someone could hijack your
connection. When you try to log into yourmachine.com, he could get “in the middle” and return
your challenge as if he was yourmachine.com. That way, he could get hold of your login password.
To make this attack harder, ssh stores the fingerprint of the server’s public key on the first
connection attempt. You will see a prompt like:
The authenticity of host ‘eisen (137.43.366.64)’ can’t be established.
RSA key fingerprint is cf:55:30:31:7f:f0:c4:a0:9a:02:1d:1c:41:cf:63:cf.
Are you sure you want to continue connecting (yes/no)
When you enter yes, ssh will add the fingerprint to your known_hosts file. you will see

Code:
Warning: Permanently added ‘eisen,137.43.366.64’ (RSA) to the list of known hosts.
The next time you login, ssh will check whether the host key has changed. A changing host key
usually indicates a man in the middle attack, and ssh refuses to connect.



Leave a Reply 6

Your email address will not be published. Required fields are marked *


ennnot

ennnot

D, E
known_hosts stored at ~/.ssh/, not at /etc/ssh/

ton_adam

ton_adam

correct, D and E

it’s possible to store the key in /etc/ssh, however the system wide known_hosts file is called /etc/ssh/ssh_known_hosts.

Armen

Armen

D and E are correct
Furthermore, RSA key fingerprint shown in the error message (not a public key) is not a right entry for the /etc/ssh/known_hosts.

iietam

iietam

Correct answers are D an E not B and D

When you connect to a host that you have not connected to before via ssh, ssh prints a message like
lava:~$ ssh lava
The authenticity of host ‘lava (134.2.14.48)’ can’t be established.
RSA key fingerprint is 9e:1a:5e:27:16:4d:2a:13:90:2c:64:41:bd:25:fd:35.
Are you sure you want to continue connecting (yes/no)?
Usually, you say yes and enter your password. With this, you accept the encryption key the server sent you as the actual encryption key of the server (as opposed to an encryption key some eavesdropper might have sent you who sits between you and the server you connect to). You are supposed to accept the encryption key only if you compared the received encryption key with the actual encryption key of the server by comparing their fingerprints. However, how do you get the fingerprint of the actual encryption key?
Reference:
http://www.lysium.de/blog/index.php?/archives/186-How-to-get-ssh-server-fingerprint-information.html