CIS 225

Lecture 11: User Management

User Accounts

• Allows multiple people to share resources
• Each user can have different permissions
• Aids in auditing (who did what)
• Protects system from unauthorized use

Authentication vs. Authorization

• Authentication - Confirming a user is who he or she claims to be (logging in)
• Authorization - Allow an authenticated user access to specific resources
• Authentication DOES NOT IMPLY Authorization

Authentication Methods

One or more of the following factors

• Ownership factors - something user has
• Knowledge factors - something user knows
• Inheritance factors - something user is or does

Authorization Methods

• Security Policies
• Access Control Lists (ACL)

User Identification

• Operating systems refer to users by a unique identifier
  • Linux: user identifier (UID)
  • Windows: security identifier (SID)
• This allows user to change usernames without affecting the account

User Account Information

• UID / SID
• Username
• Password
• Home directory
• Group(s)

Groups

• List of user accounts
• Aid in assigning access to users
• Each user may be a part of one or many groups
• Unique identifier
  • Linux: group identifier (GID)
  • Windows: security identifier (SID)

Windows 8 Accounts

Control Panel

Windows 8 Accounts

Computer Management

Windows 8 Default Accounts

• Administrator
  • Access to everything
  • Cannot be deleted
  • Disabled by default
  • Has no password by default
• Guest
  • Limited access
  • Disabled by default

Windows 8 Pseudo Accounts

• LocalSystem - system-level tasks & services
• LocalService - fewer rights than LocalSystem
• NetworkService - fewer rights than LocalService, but allows network access

Windows 8 Default Groups

• Administrators - complete access
• Event Log Readers - read event logs
• Guests - access system only
• Power Users - not used
• Remote Desktop Users - log on remotely
• Users - normal users

Many others, refer to documentation

User Account Control

• Protects the system from unwanted changes
• Allows administrators to run commands from a non-administrator account

Local Group Policy Editor

WIN+R - gpedit.msc

Ubuntu Account Types

• Super User (root)
  • Complete control
  • Disabled by default
  • UID = 0; GID = 0
• Regular User
  • User who can log on to the system
• System User
  • Used by programs and services to access the system

Ubuntu Accounts

Regular Users:

• UID: starting at 1000 and up
• Each account has a private group created with matching GID

Ubuntu Accounts

System Settings

/etc/passwd

/etc/shadow

Commands

• groupadd - add a group
• groupdel - remove a group
• groupmod - modify group
• gpasswd - change group administrator or password
• useradd - add a user
• userdel - remove a user
• usermod - modify a user
• passwd - change password

sudo

• Short for "super user do"
• Allows regular users to run commands as root
• User and rights listed in /etc/sudoers
• Add users to the "sudo" or "admin" group to give them access

Reading

• Windows 8 Book - Chapter 13
• Ubuntu Unleashed - Chapter 9

Assignments

• Lab 4 - Scripting 2: Due 10/7 @ 11:59 PM
• Lab 5 - User & File Management: Due 10/14 @ 11:59 PM

Exam Results

• Curve: 6 points
• Max - 84/84, Min - 47/84
• Avg - 71 (84%), Median - 72 (85%)
• 3 MC questions not missed
• 3 questions missed by >50% of class
• MC - Avg 17.9/24, Median 19/24