Bash Scripting in Linux

Scenario

I am a security professional at a large organization. I mainly work with the research team. Part of my job is to ensure users on this team are authorized with the appropriate permissions. This keeps the system secure while ensuring everyone can access the files they need for work.

My task is to examine existing permissions on the file system. I need to determine if the permissions match the current authorization provided by management. If they do not match, I must modify the permissions to authorize the appropriate users and remove unauthorized access.

Project Description

In this project, I used the Bash Shell in Linux to change file permissions for a research team in an organization. Management requested changes within the projects directory and provided clear instructions on permissions for each directory and file. 

Describe the permissions string

The permission string uses 10 figures to show permissions across three types of file owners: user, group, and other. The first character shows whether the item is a directory or file. The remaining 9 characters denote permissions in groups of three. 

1. Positions 2 to 4 show permissions for the user.

2. Positions 5 to 7 show permissions for the group.

3. Positions 8 to 10 show permissions for the other type.

Let’s review this copied example from position 1 to 10. It is the last file listed in the screenshot above.

-rw-rw-r-- 1 researcher2 research_team   46 Aug  6 18:55 project_t.txt

• 1st: - means this is a file and not a directory.

• 2nd: r means the user has read permission.

• 3rd: w means the user has write permission

• 4th: - means the user does not have execute permission.

• 5th: r means the group has read permission.

• 6th: w means the group has write permission.

• 7th: - means the group does not execute permission.

• 8th: r means other has read permission.

• 9th: - means other does not have write permission.

• 10th: - means other does not have execute permission.

Summary

This activity enforced the security principle of least privilege in the organization. It ensured that only researchers with an immediate and direct need of access to files had them. Where the security team found discrepancies, we made immediate changes. Directions like this can come from management after security procedures change or when permission changes become possible or necessary after a research project has either moved to a new milestone or changed course. Authorization changes can also occur if a user changes positions in an organization or has left the organization.