Ch18 Encryption Exam

Ch18 Encryption Exam

1. Which file is used to configure SSH clients?

   • /etc/sshd_config 
   • /etc/ssh/ssh_config 
   • /etc/ssh/sshd_config 
   • /etc/ssh_config

2. The SSH utility is provided by the OpenSSH package.

   True or False?

   • True 
   • False

3. The system has a /etc/ssh/ssh_config file and the user Mike also has a ~/.ssh/config in his home directory. Which file will be used when David connects to a server via SSH?

   • ~/etc/.ssh/config 
   • Both files will be used 
   • /etc/ssh/ssh_config 
   • ~/.ssh/config

4. What does the ~/.ssh/id_rsa file contain?

   • RSA public key of the user 
   • RSA private signature of the user 
   • RSA public signature of the user 
   • RSA private key of the user

5. What does the entry AllowGroups dba netusers in the /etc/ssh/sshd_config indicate?

   • Users who are part of the dba and netusers groups will be allowed access 
   • Users with usernames dba and netusers will be allowed access 
   • Users who are not part of the dba and netusers groups will be allowed access 
   • Users who are part of the dba and netusers groups will not be allowed access

6. The _____ command is used to generate SSH keys.

   • sshkey-gen
   •  ssh-keygen 
   • sshgen-key 
   • ssh-genkey

7. The size of a DSA key is:

   • Exactly 1024 bits 
   • Exactly 1000 bits 
   • Exactly 768 bits 
   • Exactly 2048 bits

8. Which of the following is not an authentication method supported by SSH?

   • Password Authentication 
   • Signature Authentication 
   • Host Based Authentication 
   • Public Key Authentication

9. Which file on the server holds the public keys of the hosts that need to be authenticated?

   • /etc/ssh/ssh_known_hosts 
   • /etc/ssh/ssh_hosts 
   • ~/ssh/ssh_known_hosts 
   • /etc/ssh/ssh_hosts_known

10. Which of the following entries in /etc/ssh/sshd_config turn on host based authentication?

    • HostbasedAuthentication: yes 
    • HostbasedAuthentication enable 
    • Hostbased_Authentication yes 
    • HostbasedAuthentication yes

11. Which of the following utility programs are not provided by OpenSSH?

    • smv 
    • ssh 
    • scp 
    • slogin

12. What is the function of the ssh-agent?

    • Cache the decrypted public key and provide it to client programs 
    • Cache the decrypted private key and provide it to client programs 
    • Decrypt the private key and provide it to client programs 
    • Generate the signature using the private key

13. Which command is used to add private keys to the SSH agent’s repository?

    • ssh-addkey 
    • ssh-agentadd sshadd ssh-add ssh-addkey 
    • ssh-add 
    • sshadd

14. You want to ensure that the ssh-agent is run for all users, which command can be used for this?

    • /etc/ssh/ssh_known_hosts 
    • /etc/inittab 
    • /etc/profile 
    • /etc/ssh/userprofile

15. The ssh-add utility can be used to add only RSA keys.

    True or False?

    • True 
    • False

16. The ssh-add program ran for user maria, but his RSA identity files were not added, what could be the reason for this?

    • The file /home/maria/.ssh/id_rsa had read permissions for no other user except Maria 
    • The file /home/maria/.ssh/id_rsa has read permissions only for Maria 
    • The file /home/maria/.ssh/id_rsa had read and write permissions only for Maria 
    • The file /home/maria/.ssh/id_rsa has read permissions for users other than Maria

17. SSH Tunneling is the same as _____.

    • SSH Porting 
    • SSH Encoding 
    • SSH Encryption 
    • SSH Port Forwarding

18. Which of the following entries in /etc/ssh/sshd_config turn on SSH tunneling?

    • AllowTcpPortForwarding yes 
    • AllowTCPIPForwarding yes 
    • AllowTcpForwarding yes 
    • AllowPortForwarding yes

19. Which of the following commands are used to setup SSH tunneling?

    • ssh -p 
    • ssh -l 
    • ssh -L 
    • ssh -t

20. Which of the following commands will start a SSH session with X11 support?

    • ssh -X marks.gsource.com 
    • ssh -x marks.gsource.com 
    • ssh -l marks.gsource.com 
    • ssh -L marks.gsource.com

21. Which standard is GnuPG based on?

    • Linux Good Privacy (LGP) 
    • Pretty Good Privacy (PGP) 
    • SSH Good Privacy (SGP) 
    • Unix Good Privacy (UGP)

22. Which is the default configuration file used by GnuPG?

    • ~/.gnu/gpg.conf
    • ~/.gnupg/.gpg.conf
    • ~/gnupg/gpg.conf
    • ~/.gnupg/gpg.conf

23. Which command is used to generate a GnuPG key?

    • gpg -gen-key
    • gpg --gen-key
    • gpg-gen --key
    • gpggen --key

24. The gpg command operates in a ____ mode.

    • verbose
    • interactive
    • silent
    • batch

25. Which of the following algorithms are not supported by GnuPG for key generation?

    • DSA
    • Elgamal
    • One-way Hash
    • RSA

26. The SSH and GnuPG keys can be protected by an optional passphrase.

    True or False?

    • True
    • False

27. Which of the following is not a function provided by GnuPG?

    • Providing encrypted channel for communication
    • Encryption
    • Accessing public keys
    • Digital signature

28. Which command is used to verify the signature of a package?

    • gpg -V pkg.sig
    • gpg --verify pkg.sig 
    • gpg -v pkg.sig 
    • gpg verify pkg.sig

29. The ECDSA private key for a user is _______.

    • ~/.ssh/ecdsa.priv 
    • /etc/ssh/ssh_config 
    • ~/.ssh/id_rsa.pub 
    • ~/.ssh/id_ecdsa

30. The /etc/ssh/ssh_host_ed25519_key.pub file is used by sshd as part of a key value pair.

    True or False?

    • True 
    • False

31. The configuration file /etc/ssh/ssh_host_ecdsa_key is used by the __________ program for ________.

    (choose two)

    • telnet 
    • public-private keypair authentication 
    • sending data in clear text 
    • sshd

32. Which public key file is used by sshd to authenticate clients?

    • /home/sysadmin/.gnupg/public-keys-v1.d 
    • sshdhost_ed25519_key.pub 
    • ssh_host_ed25519_key.pub 
    • /etc/ssh/publickey.conf

33. The gpg-agent daemon caches passphrases only until the next user logs in.

    True or False?

    • True 
    • False