We add a new user to our Linux Mint Mate system.
We add a new user and assign the new user a password that we create and we encrypt the new users home folder.
We create a second new user and give this second new user a password, but this time we do not encrypt this users home folder.
We look at the advanced settings and see how to add an office location, work phone number and home phone number. We talk about the User Privileges Tab and I mention that I gave one user all the privileges (in this tab) and the other user no privileges (in this tab), and saw no difference between the two (with Linux Mint Mate 7.1)
We also see how to deactivate an account, We see where the home folder is, that we will not talk about the shell in this series, that a main group for this account has not (yet) been assigned and that we are not going to talk about the user ID.
We look at the home folders and see we can not view Jacks home folder, because it is encrypted, but since we are the root user, if we don't know Jacks password, we can change it to something we do know and log in to this user-ID and view what is in the home folder. Looking at Jill's home folder, there is nothing in there (yet) because we have not yet logged in as Jill.
We login as user Jill and we see the home folder has created some default folders in the home folder, we see Jill can change her password and that she now has a group connected to that login ID with the same name as the login ID.
We see that Jill can not see Jack's (encrypted) home folder, but Jill can see the root User Michael's folder. She can view and execute files in that users home folder, but she can not add or edit any files or folders. Jack is able to see the root user Michael's home folder as well, but that is not shown in the video.
Sorry, User permissions is a miss-leading title, I should have given this a title of “Folder Permissions”, but the movie was completed before I realized my mistake. These same permissions apply to files as well as folders.
To prevent any user on the system from being able to view our files in our home file, we change the permissions.
In video FromXPtoLinux (28), we saw that user Jill could view any files in my home folder, Jack can as well. One thought to prevent that from happening is to encrypt the home folder but, since we are the root user, we would need to reinstall Linux Mint Mate to encrypt the home folder, besides, the reason we did not encrypt the home folder was because we wanted to be able to access the files, if for some reason, we can't login.
The first thing we do is we go into the preferences and show the permissions for the files.
The permissions for my home folder are drwxr-xr-x the first letter explains this is a directory, the next three letters are for the owners permissions, meaning the owner can Read, Write, (meaning change, update, and delete files), and eXecute files in this folder.
The next three characters are for the group (will will talk about this in the next video) the group can read and eXectue files, but not Write (meaning edit, update, or delete and files in this folder).
The last three characters are for anyone else on the system, and we can see anyone can read and execute files in my home folder, so I want to change these.
We change the permissions by right clicking on the folder, clicking on properties, then the permissions tab, we set the "others" or all users permissions to no access, then we login as Jill and show that she can no-longer view my files.
We log back in as Michael and look at the Octal permissions and see that d for directory translates to 40 and a – or non directory file translates to 100 (there are other options for this character, but we will not be looking at them in this video).
The numeric values are Read = 4, Write = 2, Execute = 1, and we show the owner has an octal permission of 7 (4+2+1), a group that has read and execute permissions has an octal permission of 5 (4+0+1) and users with no permissions have an octal permission of 0
We look at how to create a group and assign group privlges for a folder or file.
We start by looking at the file permissions on a folder and review that every file or folder we create is assigned a default group of the user ID that created it.
Whe then go into Menu, Administration, Users and Groups, and select manage groups.
Most of the groups listed are outside of the scope of this introduction to Linux series, but we do look at the Michael group and add Jill to the Michael group.
We show that Jill can now view everything Michael has created, because the group Michael because the default group of Micahel is assigned to everything that logon ID has created. We also see that Jill can view who is in the group Jill, but she can not change this. Parents who want to monitor what their child is doing on the computer, may want add themselves to their childs groupname.
We then create a new group projectx and add Jack and Michael to this group. A folder is created in the Michael home folder and the group access is changed to allow anyone in the projectx group to Create, Read, Update, or Delete anything in that folder. We must also change the group access of the Michael home folder to give the projectx group file access, or they wont be able to get to the new Project X folder – doing this changes Jills access, she will no longer have access to any of Michaels files or folders.
We show that when Jack (or anyone) in that group creates a file or folder in the new Project X folder, they must update the group permissions, because the default is to assign a group of the longin ID that created that file or folder.