Secure Encryption

Question 1

~/.gnupg

Answer 1

Hidden directory in each home with key ring and configuration files.

Question 2

gpg

Answer 2

Generate, list, import, export, revoke.

: decrypt file if public key available.

Question 3

gpg — Switches.

Answer 3

—import: import public key into key ring.
—list-keys: list keys on key ring.
—gen-revoke : Starts revocation process. Requires cause, comment, passphrase for your key to create revocation certificate.
—export: export public key by ID.
—gen-key: starts process for creating public key. Requests kind, size, expiration time, real name, email, comment, passphrase.
—keyserver: used with —send-keys to send keys to key server.
—send-keys:

Question 4

gpg - switches

Answer 4

• o: output name (file)
• r: specify recipient.
• e: encrypt given file with preceding recipient info with your default public key. combined as -r “” -e
• a:

Question 5

sshd_config

Answer 5

In /etc/ssh. Contains configuration information.
HostKey: each line starting describe file location for each encrypted connection possible.
PermitRootLogin: enables SSH login for root if yes.
X11Forwarding: Dictates if X11 windows can be sent.

Question 6

~/.ssh

Answer 6

Individual user configuration for ssh. Such as known_hosts, containing IPaddr/hostname, encryption algorithm, and fingerprint.
When creating new key, id_rsa remains on system, id_rsa.pub is sent to system trying to connect. If either differ, no connection.

Question 7

-ssh-keygen

Answer 7

Generates ssh keys. Can provide passphrase for key for multi-factor.

• b: indicate bit length. Default 2048.
• t: type of encryption.

Question 8

ssh-copy-id

Answer 8

Will copy public ssh key to another system, set up proper permissions for the authorized_keys file on remote host.

Question 9

ssh-agent

Answer 9

Acts as a wrapper around an environment so that it can handle authentication for key files that use passphrases.
Ex: ssh-agent bash sets wrapper around bash.
Use with ssh-add.

Question 10

ssh-add

Answer 10

Adds a passphrase to the ssh-agent.

Question 11

authorized_keys

Answer 11

Within .ssh, stores keys set up by ssh-copy-id, indicates which systems for each fingerprint.

Question 12

ssh

Answer 12

-Y: improved security for X11.