AWS User Creation

Two files to create new user entries with an SSH key and zip all the data for download

Setup

The application pwgen and zip must be installed.

Checkout the scripts from git into the /root/ folder or any other folder. The folder holding the script must be owned by root and have 600 permissions

cd /root/
git clone http://gitlab-ap.factory.tools/scripts-collections/aws-user-create.git users
chown root. users
chgrp 600 users

Alternate download: git clone https://git.tequila.jp/ScriptsCollections/AwsUserCreate.git users

Folders

Inside the base folder there are

• ssh-keygen for temporary holding the PEM/PUB files
• zip file which holds the created user list, password and PEM/PUB files

Options

-g (go)

If not set, the script will not run.

-t (test)

Run in test mode. This will NOT create any groups or users. Nor will it create any ssh key files. user_password output file will be written with .TEST extension

-i (info)

Do not created anything at all, just print out info strings

User list creation

In the /root/users/ folder there needs to be a file called 'user_list.txt'

This is a CSV type file with the following layout

ID	Username	Group and Sub Group	SSH Access Type	Optional Password	Override host name	Override ssh key type

1: The ID, Username and Group column must be filled. 2: For sub groups add them with a , The first group is the master group 3: SSH Access type as: allow/forward. allow is default 4: If the password column is filled, the string from here will be used as the PEM Key password. 5: If a override hostname is set it will be used instead of hostname 6: If the ssh key type is set, it will override the default ed25519 type. Only rsa is allowed. This is for setting up backwards compatible lists. Change is not recommended

The ID can be any string in any form. It can also be left empty. It is not used at the moment

The file can hold comments. The first character in the line must be a #

Example file

#user_id;user_name;group,subgroup;ssh access type;override password;override hostname;override ssh type
user1;some.name;group-a;allow;;hostname;
user2;othername;group-a;allow;;;
# I am a comment
;username;groupC;allow;setpassword;;
...

User with existing PEM key

If we want to create a user that already has a PEM key or we want to have the user use the same PEM key for login we can copy the existing pub key into the ssh key folder ssh-keygen-created-pub

The public PEM key file format is as followed

hostname#main group name#user name#ssh key type.pem.pub

In the example above for user1 the file name would be for some.name and group-a

hostname#group-a#some.name#ssh-keytype.pem.pub

Copy this file into the ssh-keygen folder and add the user to the 'user_list.txt' file. This must be with the same name and group as set in the PEM public key.

Example:

PEM public key file is hostname#Bgroup#foobar#ed25519.pem.pub Then the line for the 'user_list.txt' must be

[some user id];foobar;Bgroup;;

Note that [some user id] can be any string or left empty

Script run

The current directory MUST be the directory where 'user_list.txt' is stored.

$> cd /root/users

Then run the script without any options

$> /root/bin/create_user.sh

Sample output for above example file

++ Create 'some.name:group-a'
 > Create ssh key-pair '/root/users/ssh-keygen/hostname#group-a#some.name#ed25519.pem'
Generating public/private rsa key pair.
Your identification has been saved in /root/users/ssh-keygen/hostname#group-a#some.name#ed25519.pem.
Your public key has been saved in /root/users/ssh-keygen/hostname#group-a#some.name#ed25519.pem.pub.
The key fingerprint is:
SHA256:Ufalh41IRLJTHZlsaEJVK5N7cOYhxRdqf3fCDxhHdCA egrp10070.globalad.org: some.name@group-a
The key's randomart image is:
+---[RSA 3072]----+
|       .o+O*E=*o.|
|        .Bo=B@.. |
|        +oB.&.+  |
|         o @ O   |
|        S . + = +|
|           .   =o|
|                .|
|                 |
|                 |
+----[SHA256]-----+
 > Create .ssh folder
 > Add public into authorized_keys
 > Secure folder .ssh and authorized_keys file

If the public pem file is already provided the output will be a bit different

++ Create 'some.name:group-a'
 < Use existing public ssh key '/root/users/ssh-keygen-created-pub/hostname#group-a#some.name#ed25519.pem.pub'
 > Create .ssh folder
 > Add public into authorized_keys
 > Secure folder .ssh and authorized_keys file

There is no SSH key generate output but Use existing public ssh key information line

If the user has been created, the creating will be skipped

-- Skip 'some.name:group-a'

Script output

The generated users and the passwords are stored in the 'user_password.YYYYMMDD-hhmmss.txt' file

For above the output will be

2020-11-27 13:51:01;sever.hostname.org;hostname;some.name;Aeh9uph8Oo
2020-11-27 13:51:02;sever.hostname.org;;othername;AePejoo9ch
2020-11-27 13:51:02;sever.hostname.org;;username;setpassword

Note that the sever.hostname.org is set from the hostname of the server where the script is run The name hostname is set if the hostname field in hser user_list.txt file is set

If a existing pem public key is used, the entry for a new user will be

2020-11-27 13:53:18;sever.hostname.org;;some.name;[ALREADY SET]

Not that the password field has now [ALREADY SET]

Get the user data

In the zip/ folder there is a file named users.YYYYMMDD-hhmmss.zip; This file should be copied localy and then removed from the server

NOTE Do not remove the public key data in ssh-keygen-created-pub/ or the script will create new keys for users in the user_list.txt file

SSH helper

change password or extract public key from pem file

PEM key password reset

The SSH PEM key password can be reset or changed with

$> ssh-keygen -p -f [PEM].pem -P old_passphrase -N new_passphrase

To remove the password use this -N ""

[!notice] If the command is used like this it will be stored in the history file. For scurity reason it is recommended to not give the -P and -N options when changing the password

Missing PUB key

The public key part can be extracted from the SSH PEM key with

$> ssh-keygen -y -f [PEM].pem > [PEM].pem.pub

[PEM] is the placeholder for the filename

Lock and unlock uses

If a user should be stopped from logging in via ssh the user needs to be removed from the sshallow or sshforward groups. Note that the sshforward group only exists on jump hosts and can normally be ignored.

Default 100% ignored users are 'root', 'ec2-user', 'admin', 'ubuntu'

Lock users

bin/lock_users.sh -t <user 1> <user 2> ...

The -t flag is for test run.

If the user is not in the sshallow or sshreject group the change will be skipped. Locked users will be moved to the sshreject group

Unlock users

If a user exists in the sshreject group the user can be unlocked

bin/unlock_uses.sh -t -s <allow|forward> <user 1> <user 2> ...

Like the lock user script it will only work on users in the sshreject group. But here the target allow / forward group must be selected.

If not set it defaults to allow, if a user_list.txt file with this user exist it will try to extract this data if the -s option is not set

Last login check scripts

There are two scripts that can be user to check if and when the user has logged in the last time.

Because of users who do not open shells (for example sftp users) we cannot rely on lastlog, so a script called collect_login_data.sh exists that parses the systemd logind info or /var/log/secure for user authentication data.

Data is stored in auth-log/user_auth.log folder as user;last login date

This script should be run every day via crontab as root:

0 1 * * * root /root/users/bin/collect_login_data.sh

The script check_last_login.sh will go through the ssh allow groups (sshallow/sshforward) users and flag out those that have not logged in, in the last 60 days and recommend to lock them. The script will also check for user accounts that never logged in and where created in the last 30 days and recomment to lock them too.

This script will first check the auth-log/user_auth.log file, then lastlog output and finally check for creation time in passwd file or home director for when the user was created.

Currently only information is printed out and no action is done itself.

The script can be put into the crontab and run once a month, it prints to STDOUT so a mail pipe with a proper subject is recommended

0 2 1 * * root /root/users/bin/check_last_login.sh | mail -s "User Account check: $(hostname)"

For processable output there is a "csv" and "json" option to output the data in CSV or JSON format

Example csv

Hostname,Username,Main Group,SSH Group,Account Created Date,Account Age,Last Login Date,Last Login Age,Login Source,Never Logged In,Status
some.host,name_a,staff,sshallow,2021-11-18,764,,,,true,[!] Never logged in: account created 764 days ago
some.host,name_b,staff,sshallow,2021-11-15,767,2023-12-20 22:18:36,1,ssh,false,OK [ssh]
...

{
  "Info": {
    "Hostname": "host.name",
    "Date": "2023-12-21 13:11:45",
    "MaxAgeLogin": 90,
    "MaxAgeCreate": 30
  },
  "Users": [
    {
      "Username": "name_a",
      "SshGroup": "sshallow",
      "MainGroup": "staff",
      "SubGroups": [],
      "AccountCreatedDate": "2021-11-18",
      "AccountAge": "764",
      "LastLoginDate": "",
      "LastLoginAge": "",
      "LoginSource": "",
      "NeverLoggedIn": true,
      "Status": "[!] Never logged in: account created 764 days ago"
    },
    {
      "Username": "name_b",
      "SshGroup": "sshallow",
      "MainGroup": "staff",
      "SubGroups": [
        "sudo",
        "users",
        "group_a",
        "group_b",
      ],
      "AccountCreatedDate": "2021-11-15",
      "AccountAge": "767",
      "LastLoginDate": "2023-12-20 22:18:36",
      "LastLoginAge": "1",
      "LoginSource": "ssh",
      "NeverLoggedIn": false,
      "Status": "OK [ssh]"
    },
  ]
}

Delete users

bin/delete_user.sh -t -b <user 1> <user 2> ...

Deletes one or more users

• -t test, no action done
• -b do not create a backup

Unless -b is set the home folder and public key in /etc/ssh will be backed up. Flags user with #DELETED-YYYYMMDD_HHmmss:id;... in the user_list.txt file

Rename user

bin/rename_user.sh -t -o <current user name> -n <new user name>

Renames a user including the home directory, public key files and any other connected data. Also updates the user_list.txt