Difference between revisions of "Operating Systems/Linux/Ubuntu/Ubuntu 16.04 LTS/Program-Settings"

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# Dictionary-based password checks can be enabled by adding the line <code>password requisite pam_pwquality.so</code> to the end of the file
 
# Dictionary-based password checks can be enabled by adding the line <code>password requisite pam_pwquality.so</code> to the end of the file
 
#* This is important because it prevents users from using common words in their password
 
#* This is important because it prevents users from using common words in their password
===Remembering Previous Passwords===
+
===Prevent Duplicate Passwords===
 
# <code>sudo nano /etc/pam.d/common-password</code>
 
# <code>sudo nano /etc/pam.d/common-password</code>
# Enabling previous passwords being remembered can be enabled by adding the line <code>password required pam_unix.so remember=5</code> to the end of the file
+
# Duplicate passwords can be prevented by adding the line <code>password required pam_unix.so remember=5</code> to the end of the file
#* This is important because it will prevent users from using the same password multiple times
+
#* This will make the system remember past passwords so that users can't use the same password multiple times.
 +
 
 
===Max/Min password age===
 
===Max/Min password age===
 
# <code>sudo nano /etc/login.defs</code>
 
# <code>sudo nano /etc/login.defs</code>

Revision as of 22:49, 30 November 2023

Password Security

When you need to mess with password security policy in Linux three useful files are /etc/security/pwquality.conf, /etc/pam.d/common-password, and /etc/login.defs

Minimum Password Length

  1. sudo nano /etc/pam.d/common-password
  2. The minimum password length can be set to 10 by adding "minlen=10" to the end of this line: password [success=1 default=ignore] pam_unix.so obscure yescrypt minlen=10

Dictionary Based Password Checks

  1. sudo nano /etc/pam.d/common-password
  2. Dictionary-based password checks can be enabled by adding the line password requisite pam_pwquality.so to the end of the file
    • This is important because it prevents users from using common words in their password

Prevent Duplicate Passwords

  1. sudo nano /etc/pam.d/common-password
  2. Duplicate passwords can be prevented by adding the line password required pam_unix.so remember=5 to the end of the file
    • This will make the system remember past passwords so that users can't use the same password multiple times.

Max/Min password age

  1. sudo nano /etc/login.defs
  2. Scroll very far down until you reach the line PASS_MAX_DAYS. Set it equal to 30.
    • This is important because it requires users to change their password every 30 days

Other

Disable IPv4 Forwarding

  1. sudo nano /etc/sysctl.conf
  2. Add the line net.ipv4.ip_forward=0 to the end of the file
  3. sudo sysctl -p (this applies the settings)
  4. Use the command sysctl net.ipv4.ip_forward to check if it's disabled (0 means it's disabled)