PoojaMoolya: Created page with "{| border=1 |- || '''Time''' || '''Narration''' |- || 00:01 || Hello and welcome to the spoken tutorial on '''Group Password '''and''' Login.''' |- || 00:08 || In this tutoria..."

2022-09-07T11:13:58Z

Created page with "{| border=1 |- || '''Time''' || '''Narration''' |- || 00:01 || Hello and welcome to the spoken tutorial on '''Group Password '''and''' Login.''' |- || 00:08 || In this tutoria..."

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{| border=1
|-
|| '''Time'''
|| '''Narration'''
|-
|| 00:01
|| Hello and welcome to the spoken tutorial on '''Group Password '''and''' Login.'''
|-
|| 00:08
|| In this tutorial we will learn about

'''newgrp command'''

|-
|| 00:14
|| Securing a '''group '''with''' password'''

|-
|| 00:17
|| Login to a''' group '''as '''group member'''

|-
|| 00:20
|| Login to a''' group '''as '''non-member'''

|-
|| 00:24
|| We will do this through some examples.
|-
|| 00:28
|| To record this tutorial, I am using '''Ubuntu Linux 16.04 OS'''
|-
|| 00:35
|| To practice this tutorial,

you should have gone through the '''Linux System Administration '''tutorials''' '''on this website and

|-
|| 00:45
|| you must have '''root access''' to your computer.

|-
|| 00:49
|| Earlier in the series, we had created two '''users, suraj '''and''' testmod'''.

|-
|| 00:56
|| Let us check the status of these '''users'''.
|-
||01:00
|| Open the '''Terminal '''by pressing '''Ctrl, Alt and T '''keys simultaneously on the keyboard.
|-
|| 01:09
|| First, login as '''superuser '''or '''root user'''.
|-
|| 01:16
|| Here onwards, please remember to press the '''Enter''' key after typing each '''command'''.
|-
|| 01:23
|| Now type '''id''' '''space''' '''suraj'''
|-
|| 01:28
|| The output indicates that '''Suraj''' belongs to '''primary group CSE.'''

|-
|| 01:34
|| He is not a member of any additional '''supplementary group'''.
|-
|| 01:39
|| Now type '''id space testmod'''
|-
|| 01:44
|| The output shows that '''user testmod''' belongs to '''primary group Electronics'''.

|-
|| 01:51
|| He is also a member of two '''supplementary groups -''' '''music_club''' and '''literature_club'''
|-
|| 02:00
|| For this demonstration, we will use the '''group music_club'''.

|-
|| 02:06
|| We will first check the details of the '''group music_club.'''
|-
|| 02:11
|| Type the command as shown
|-
|| 02:15
|| The output shows the details of the '''group music_club.'''

|-
|| 02:20
|| Here the value of the second '''field''' i.e. the '''password field''' is '''x'''.

|-
|| 02:26
|| So, for '''password''' details we have to refer to the '''/etc/gshadow '''file.
|-
|| 02:34
|| Type the command as shown.
|-
|| 02:38
|| Here, the value of the second '''field''' is an exclamation mark.

|-
|| 02:43
|| This means that the '''password''' is either invalid or not set.
|-
|| 02:49
|| Also, we can see that '''testmod''' is listed as a member of the '''group music_club.'''
|-
|| 02:56
|| It is clear that the '''group music_club''' does not have a valid '''password'''.

|-
|| 03:03
|| Now, let us check how a member like '''testmod''' and a non-member like '''suraj''' can login to this '''group'''.

|-
|| 03:12
|| For login to a '''group''', we will use''' newgrp command.'''
|-
|| 03:17
|| The '''newgrp command '''is used to change the current '''group ID '''during a '''login session'''.

|-
|| 03:24
|| The syntax of '''newgrp command '''is'''-''' '''newgrp space hyphen space Newgroup'''

|-
|| 03:33
|| Here, '''hyphen''' and '''Newgroup''' are optional parameters

|-
|| 03:39
|| '''Newgroup''' is either a '''group ID '''number or a '''group''' name located in '''/etc/group'''.

|-
|| 03:47
|| Then '''newgrp''' refers to the file''' /etc/passwd''' for the particular entry of the '''user'''.

|-
|| 03:57
|| And changes the current '''group''' to the default '''group''' listed in the file '''/etc/passwd''' for the '''user'''.

|-
|| 04:07
|| Optional '''hyphen flag''' re-initializes the '''user's '''environment as though the '''user '''has just logged in.

|-
|| 04:16
|| Otherwise, the current environment remains unchanged.

|-
|| 04:21
|| For the demonstration in this tutorial, we will always use the '''hyphen flag'''.
|-
|| 04:27
|| Let me try to login to the '''group music_club '''as a member, say '''testmod'''.

|-
|| 04:34
|| For this we have to '''login''' to '''user account testmod'''
|-
|| 04:39
|| We will open a new '''terminal '''window for this.

|-
|| 04:43
|| Right click on the '''terminal.'''

|-
|| 04:45
|| From the pop-up select '''Open Terminal.'''
|-
|| 04:50
|| From this point onwards, we will use both these '''terminals'''.

|-
|| 04:55
|| We will switch from one '''terminal''' to another terminal for demonstration purpose.
|-
|| 05:01
|| In the new '''terminal''' we are logged in as '''user spoken.'''

|-
|| 05:06
|| Now, let me login as '''user testmod.'''

|-
|| 05:12
|| Then type '''id '''
|-
|| 05:15
|| '''music_club''' is listed as one of the''' supplementary groups.'''
|-
|| 05:21
|| In order to '''login''' to '''group music_club''', type- '''newgrp space hyphen space music underscore club'''
|-
|| 05:33
|| The '''command''' has executed without any error.
|-
|| 05:37
|| Type '''id '''once again.
|-
|| 05:40
|| Notice now that our current '''group''' is '''music_club'''.
|-
|| 05:45
|| Earlier it was '''Electronics'''.

|-
|| 05:49
|| So, our current''' group''' has changed.

|-
|| 05:51
|| We are logged in to '''music_club'''.

|-
|| 05:57
|| This '''login session''' will continue until we execute the '''exit command'''.
|-
|| 06:03
|| So, let’s now type '''exit '''command
|-
|| 06:07
|| Recall the '''id''' command
|-
|| 06:10
|| Now, our current group is '''Electronics'''.
|-
||06:14
|| To exit from this '''user login session''', type '''exit.'''
|-
|| 06:19
|| Notice that the '''terminal prompt '''has changed.

|-
|| 06:22
|| Currently, we are logged in as '''user spoken'''.
|-
|| 06:27
|| Now, let’s see how a non-member like '''suraj''' can '''login''' to the '''group music_club.'''

|-
|| 06:35
|| Let us try to use the same '''newgrp command''' for this purpose.
|-
|| 06:40
|| Let me '''login''' as '''user suraj'''
|-
|| 06:46
|| We are logged in as '''suraj'''.
|-
|| 06:50
|| Type '''id'''
|-
|| 06:52
|| Notice that our current '''group''' is '''CSE'''.

|-
|| 06:56
|| And there are no '''supplementary groups''' listed.

|-
|| 07:00
|| So, it's clear that '''suraj '''is not member of the''' group music_club.'''
|-
|| 07:07
|| Let me '''login''' to '''group music_club'''
|-
|| 07:12
|| It is asking the '''password'''. But we haven’t set any valid '''password''' for the '''group music_club.'''

|-
|| 07:20
|| We cannot login to the '''group music_club.'''
|-
|| 07:24
|| Press '''Control''' and '''D''' keys together to '''exit''' the '''group login''' process.
|-
|| 07:31
|| Now '''exit''' from the '''user login session'''
|-
|| 07:36
|| We are back to the '''user account spoken'''.
|-
|| 07:40
|| From this we understand that if a''' group''' does not have a valid''' password '''set,

|-
|| 07:47
|| then only a '''group '''member can use '''newgrp - group command''' to''' login''' to the''' group'''.

|-
|| 07:55
|| Non-members cannot '''login''' to the''' group'''.
|-
|| 07:59
|| So, let us secure the '''group access '''with a '''password'''.

|-
|| 08:04
|| '''Superuser''' or '''group administrator ''' can use '''gpasswd space Newgroup''' to set or change the '''password''' of a '''group.'''

|-
|| 08:15
|| '''Newgroup''' is either a '''group ID''' or a '''group''' name that you have to write in the '''command'''.

|-
|| 08:22
|| We will discuss about the '''group administrator''' in a separate tutorial later.

|-
|| 08:27
|| Let us now try to set the''' password''' as '''superuser'''.
|-
|| 08:32
|| Switch to the '''terminal''' in which we have logged in as a '''root user.'''
|-
|| 08:37
|| To set the '''password''' for the '''group music_club''', type '''gpasswd space '''the name of the '''group '''that is '''music underscore club'''
|-
|| 08:49
|| Type '''group password''' as '''pass underscore music'''

Press''' Enter'''
|-
|| 08:56
|| Retype the same '''password '''and press '''Enter.'''
|-
|| 09:01
|| Now we will repeat the '''login''' process to the '''group music_club''' as a member and also as a non-member.
|-
|| 09:09
|| Switch to the other '''terminal '''where we have logged in as user '''spoken'''
|-
|| 09:15
|| Let me login as '''user testmod'''.
|-
|| 09:20
|| Now '''login''' to the '''group music_club'''

The '''command''' has executed without any error.
|-
|| 09:29
|| Type '''id'''
|-
|| 09:31
|| Notice that our current''' group''' is now '''music_club'''.
|-
|| 09:36
|| So what do we understand from this?

|-
|| 09:39
|| Even though the '''group '''has a''' password, ''' '''group''' members will not be prompted to provide the '''password '''while logging in.

|-
|| 09:48
|| Exit from the '''group login session''',
|-
|| 09:51
|| Exit from the '''user testmod'''.
|-
|| 09:55
|| We are back to the user prompt '''spoken.'''
|-
|| 09:59
|| Now, '''suraj''' is a non-member for the '''group music_club.'''

|-
|| 10:05
|| Let’s see if '''suraj''' can use the same '''newgrp command '''to '''login''' to the '''group'''.
|-
|| 10:11
|| '''login''' as''' user suraj'''
|-
|| 10:15
|| Type the '''id command'''
|-
|| 10:18
|| As we know '''suraj''' is not a member of any '''supplementary group.'''
|-
|| 10:23
|| Now login to''' '''the '''group music_club''',
|-
|| 10:28
|| It is asking for a '''password'''.
|-
|| 10:30
|| Type '''pass underscore music '''which we set just now.
|-
|| 10:36
|| The command has executed without any error.
|-
|| 10:40
|| Type '''id '''command
|-
|| 10:43
|| Notice, our current '''group''' is now''' music_club'''.
|-
|| 10:48
|| So what do we understand from this? If the '''group''' has a '''password''' set,

Non-members have to provide the correct '''password''' in order to login to the '''group'''.

|-
|| 10:59
|| To switch back to your original '''login group''', type '''newgrp'''
|-
|| 11:05
|| Now, '''newgrp command''' is used without any '''argument'''.

|-
|| 11:10
|| It should change the current '''group''' to the default '''group''' for '''user suraj'''.

|-
|| 11:16
|| As we know the default or '''primary group''' for '''user suraj''' is '''CSE'''.

Let me check that.
|-
|| 11:23
|| Type the '''id '''command.
|-
|| 11:26
|| Notice, our current '''group''' is now '''CSE.'''
|-
|| 11:30
|| Exit from the '''group CSE '''login session
|-
|| 11:34
|| Exit from the '''group music_club '''login session
|-
|| 11:39
|| Now exit from the '''user login session'''.
|-
|| 11:43
|| We are back to the '''user session spoken'''
|-
|| 11:47
|| A note on '''group password''':

|-
|| 11:50
|| If the '''user''' is '''root''', he or she will not be prompted for a '''password'''.

|-
|| 11:56
|| If there is no '''group password''' set and the '''user''' is not listed as a member of the '''group'''.

|-
|| 12:02
|| Then the '''user''' will be denied '''access'''

|-
|| 12:06
|| '''Non-root users''' will be prompted for a '''group password'''

|-
|| 12:10
|| if the '''user''' is not listed as a '''group member''' and the '''group''' has a '''password'''.

|-
|| 12:17
|| Notice that more than one person is permitted to know the '''group password. '''

|-
|| 12:23
|| So, '''group password''' has an inherent security problem.

|-
|| 12:29
|| However, '''groups''' are a useful tool for permitting cooperation between different '''users'''.

|-
|| 12:36
|| Switch to the '''terminal''', in which we have logged in as a '''root user.'''
|-
|| 12:41
|| Exit from the '''root user.'''
|-
|| 12:44
|| This brings us to the end of this tutorial.

Let us summarize.
|-
|| 12:50
|| In this tutorial we learnt about-

'''newgrp command'''

|-
|| 12:55
|| Securing a '''group '''with '''password'''

|-
|| 12:58
|| '''Login''' to a '''group''' as a '''group member'''

|-
|| 13:01
|| '''Login''' to a''' group '''as a '''non-member'''

|-
||13:05
|| As an assignment-

Create a new '''group accounts''' for the college '''database'''.

|-
|| 13:12
|| Give a suitable '''password''' for the '''group''' created.

|-
|| 13:16
|| Create two '''users: rekha''' and '''sheetal'''.

|-
|| 13:21
|| Check details of '''user rekha''' using the '''command id'''.

|-
|| 13:26
|| Add '''rekha''' as a member of the '''group'''.

|-
|| 13:30
|| Check how the '''user rekha''' can login to the '''group accounts.'''

|-
|| 13:35
|| Check how the '''user sheetal''' can login to the '''group accounts.'''

|-
|| 13:40
|| At every step, check the details of '''group accounts '''from '''/etc/gshadow''' file.

|-
|| 13:48
|| The video at the following link summarises the Spoken Tutorial project.

Please download and watch it.
|-
|| 13:56
|| The Spoken Tutorial Project team conducts workshops using spoken tutorials and gives certificates.

For more details, please write to us.
|-
|| 14:08
|| Pls post your timed queries in this Forum.
|-
|| 14:12
|| Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.

|-
|| 14:18
|| The script has been contributed by Antara. And this is Praveen from IIT Bombay signing off.

Thanks for joining.
|-
|}

Linux-for-Sys-Ads/C2/Group-Password-and-Login/English-timed - Revision history

PoojaMoolya: Created page with "{| border=1 |- || '''Time''' || '''Narration''' |- || 00:01 || Hello and welcome to the spoken tutorial on '''Group Password '''and''' Login.''' |- || 00:08 || In this tutoria..."