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Recording sessions

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Red Hat Enterprise Linux 8

Using the Session Recording solution in Red Hat Enterprise Linux 8

Red Hat Customer Content Services

Abstract

This documentation collection provides introduction to using the Session Recording solution based on tlog with RHEL web console embedded player on Red Hat Enterprise Linux 8.

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Chapter 1. Getting started with Session Recording on RHEL

1.1. Session Recording in RHEL

The Session Recording solution in Red Hat Enterprise Linux 8 is based on the tlog package. You can use the tlog package and its associated web console session player to record and play back user terminal sessions. You can configure the recording to take place per user or user group via the SSSD service. All terminal input and output is captured and stored in a text-based format in the system journal.

Important

To not intercept raw passwords and other sensitive information, recording of the terminal input is disabled by default. Be aware that if you turn on recording of the terminal input, all entered passwords are captured in plaintext.

You can use this solution for auditing user sessions on security-sensitive systems or, in the event of a security breach, reviewing recorded sessions as part of forensic analysis. As an administrator, you can configure session recording locally on RHEL 8 systems. You can review the recorded sessions from the web console interface or in a terminal using the tlog-play command.

1.2. Components of Session Recording

There are three main components to the Session Recording solution: the tlog utility, the SSSD service and a web console embedded user interface.

tlog
The tlog utility is a terminal input/output (I/O) recording and playback program. It inserts the tlog-rec-session tool between the user terminal and the user shell, and logs everything that passes through as JSON messages.
SSSD
The System Security Services Daemon (SSSD) service provides a set of daemons to manage access to remote directories and authentication mechanisms. When configuring session recording, you can use SSSD to specify which users or user groups to record. You can configure these settings from a command-line interface (CLI) or from the RHEL 8 web console interface.
The RHEL 8 web console embedded interface
The Session Recording page is part of the RHEL 8 web console interface and you can use it to manage recorded sessions.
Important

You need administrator privileges to access the recorded sessions.

1.3. Limitations of Session Recording

These are the most notable limitations of the Session Recording solution.

  • Recordings of root user are not reliable, because the root user can circumvent the recording process.
  • Session recording does not record the terminal in a GNOME 3 graphical session. Recording terminals in graphical sessions is not supported because a graphical session has a single audit session ID for all terminals and tlog is unable to distinguish between the terminals and prevent repeated recordings.
  • If session recording is configured to log to the journal, the recorded user will see the act of recording the results of viewing the system journal or /var/log/messages. Because viewing generates logs, which then print to the screen, this causes Session Recording to record this action, which generates more records, causing a loop of flooded output.

    You can use the following command to work around this problem:

    # journalctl -f | grep -v 'tlog-rec-session'

    You can also configure tlog to limit the output. For details, see tlog-rec or tlog-rec-session manual pages.

  • To record users executing remote access commands, you must configure session recording for that user on the target host. For example, to record the following remote access command, you need to configure session recording for the admin user on the client host:

    ssh admin@client rm -f /some/file
  • All recordings are lost on reboot because the journal is stored in-memory by default on RHEL 8. To export recordings see Exporting recorded sessions to a file.

Chapter 2. Deploying Session Recording on RHEL web console

This section describes how to deploy the Session Recording solution on the Red Hat Enterprise Linux web console.

To be able to deploy the Session Recording solution you need to have the following packages installed:

  • tlog
  • SSSD
  • cockpit-session-recording

2.1. Installing tlog

Install the tlog packages.

Procedure

  • Use the following command:

    # yum install tlog

2.2. Installing cockpit-session-recording

The basic web console packages are a part of Red Hat Enterprise Linux 8 by default. To be able to use the Session Recording solution, you have to install the cockpit-session-recording packages and start or enable the web console on your system:

Procedure

  1. Install cockpit-session-recording.

    # yum install cockpit-session-recording
  2. Start or enable the web console on your system:

    # systemctl start cockpit.socket
    # systemctl enable cockpit.socket

    or

    # systemctl enable cockpit.socket --now

2.3. Enabling session recording for users and groups with SSSD from the CLI

If you use SSSD for authentication, you can configure session recording for users and groups from the command line.

Procedure

  1. Open the sssd-session-recording.conf configuration file:

    # vi /etc/sssd/conf.d/sssd-session-recording.conf
    Note

    The sssd-session-recording.conf file is created automatically once you have opened the configuration page in the web console interface.

  2. To specify the scope of session recording, enter one of the following values for the scope option:

    • none to record no sessions.
    • some to record only specified sessions.
    • all to record all sessions.
  3. Optional: If you set the scope as some add the names of users and groups in comma-separated lists.
  4. To enable the SSSD profile, run the following command:

    # authselect select sssd with-files-domain

Example 2.1. SSSD configuration

In the following example users example1 and example2, and group examples have session recording enabled.

[session_recording]
scope = some
users = example1, example2
groups = examples

2.4. Enabling session recording for users and groups with SSSD from the web UI

If you use SSSD for authentication, you can configure session recording for users and groups in the RHEL 8 web console.

Procedure

  1. Connect to the RHEL 8 web console locally by entering localhost:9090 or by entering your IP address <IP_ADDRESS>:9090 into your browser.
  2. Log in to the RHEL 8 web console.

    Important

    Your user has to have administrator privileges to be able to view recorded sessions.

  3. Go to the Session Recording page in the menu on the left.
  4. Click on the gear button in the right top corner.

    SSSD Configuration button
  5. Set your parameters in the SSSD Configuration table. Separate the lists of users and groups with commas.

    Example 2.2. Configuration of recorded users with SSSD

    SSSD Configuration

2.5. Enabling session recording for users without SSSD

Important

Red Hat does not recommend this option. The preferred option is to configure your recorded users via SSSD either from the command-line interface or directly from the RHEL 8 web console.

If you choose to manually change the user’s shell, their working shell will be the one that is listed in the tlog-rec-session.conf configuration file.

If you do not want to use SSSD for specifying recorded user or user groups it is possible to directly change the shell of the user you want to record to /usr/bin/tlog-rec-session:

  1. Change the shell.

    # sudo usermod -s /usr/bin/tlog-rec-session <user_name>

2.6. Exporting recorded sessions to a file

You can export your recorded sessions and their logs and copy them.

The following procedure shows how to export recorded sessions on a local system.

Prerequisites

  • Install the systemd-journal-remote package.

    # yum install systemd-journal-remote

Procedure

  1. Create a directory to store exported recording sessions, such as `/tmp/dir:

    # mkdir /tmp/dir
  2. Run the journalctl -o export command to export system journal entries related to tlog recordings:

    # journalctl _COMM=tlog-rec _COMM=tlog-rec-sessio -o export | /usr/lib/systemd/systemd-journal-remote -o /tmp/dir/example.journal -
    Note

    The COMM=tlog-rec-sessio COMM name is shortened due to a 15 character limit.

Chapter 3. Playing back recorded sessions

There are two methods for replaying recorded sessions:

  • the tlog-play tool
  • the RHEL 8 web console, also referred to as Cockpit.

3.1. Playback with tlog-play

You can use the tlog-play tool to play back session recordings in a terminal. The tlog-play tool is a playback program for terminal input and output recorded with the tlog-rec tool. It reproduces the recording of the terminal it is under, but cannot change its size. For this reason the playback terminal needs to match the recorded terminal size for proper playback. The tlog-play tool loads its parameters from the /etc/tlog/tlog-play.conf configuration file. You can override those parameters with command line options described in the tlog-play manual pages.

3.2. Playback with the web console

The RHEL 8 web console has a whole interface for managing recorded sessions. You can choose the session you want to review directly from the Session Recording page, where the list of your recorded session is.

Example 3.1. Example list of recorded sessions

List of recorded sessions

The web console player supports window resizing.

3.3. Playing back recorded sessions with tlog-play

You can play back session recordings from exported log files or from the Systemd Journal.

Playing back from a file

You can play a session back from a file both during and after recording:

# tlog-play --reader=file --file-path=tlog.log

Playing back from the Journal

Generally, you can select Journal log entries for playback using Journal matches and timestamp limits, with the -M or --journal-match, -S or --journal-since, and -U or --journal-until options.

In practice however, playback from Journal is usually done with a single match against the TLOG_REC Journal field. The TLOG_REC field contains a copy of the rec field from the logged JSON data, which is a host-unique ID of the recording.

You can take the ID either from the TLOG_REC field value directly, or from the MESSAGE field from the JSON rec field. Both fields are part of log messages coming from the tlog-rec-session tool.

Procedure

  1. You can play back the whole recording as follows:
# tlog-play -r journal -M TLOG_REC=<your-unique-host-id>

You can find further instructions and documentation in the tlog-play manual pages.

Chapter 4. Configuring a system for session recording by using the RHEL system role

Use the tlog RHEL system role to record and monitor terminal session activities on your managed nodes in an automatic fashion. You can configure the recording to take place per user or user group by means of the SSSD service.

The session recording solution in the tlog RHEL system role consists of the following components:

  • The tlog utility
  • System Security Services Daemon (SSSD)
  • Optional: The web console interface

4.1. Configuring session recording for individual users by using the tlog RHEL system role

Prepare and apply an Ansible playbook to configure a RHEL system to log session recording data to the systemd journal.

With that, you can enable recording the terminal output and input of a specific user during their sessions, when the user logs in on the console, or by SSH.

The playbook installs tlog-rec-session, a terminal session I/O logging program, that acts as the login shell for a user. The role creates an SSSD configuration drop file, and this file defines for which users and groups the login shell should be used. Additionally, if the cockpit package is installed on the system, the playbook also installs the cockpit-session-recording package, which is a Cockpit module that allows you to view and play recordings in the web console interface.

Prerequisites

Procedure

  1. Create a playbook file, for example ~/playbook.yml, with the following content:

    ---
    - name: Deploy session recording
      hosts: managed-node-01.example.com
      tasks:
        - name: Enable session recording for specific users
          ansible.builtin.include_role:
            name: rhel-system-roles.tlog
      vars:
        tlog_scope_sssd: some
        tlog_users_sssd:
          - <recorded_user>
    tlog_scope_sssd: <value>
    The some value specifies you want to record only certain users and groups, not all or none.
    tlog_users_sssd:: <list_of_users>
    A YAML list of users you want to record a session from. Note that the role does not add users if they do not exist.
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  1. Check the SSSD drop-in file’s content:

    # cat cd /etc/sssd/conf.d/sssd-session-recording.conf

    You can see that the file contains the parameters you set in the playbook.

  2. Log in as a user whose session will be recorded.
  3. Play back a recorded session.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.tlog/README.md file
  • /usr/share/doc/rhel-system-roles/tlog/ directory

4.2. Excluding certain users and groups from session recording by using the the tlog RHEL system role

You can use the tlog_exclude_users_sssd and tlog_exclude_groups_sssd role variables from the tlog RHEL system role to exclude users or groups from having their sessions recorded and logged in the systemd journal.

The playbook installs tlog-rec-session, a terminal session I/O logging program, that acts as the login shell for a user. The role creates an SSSD configuration drop file, and this file defines for which users and groups the login shell should be used. Additionally, if the cockpit package is installed on the system, the playbook also installs the cockpit-session-recording package, which is a Cockpit module that allows you to view and play recordings in the web console interface.

Prerequisites

Procedure

  1. Create a playbook file, for example ~/playbook.yml, with the following content:

    ---
    - name: Deploy session recording excluding users and groups
      hosts: managed-node-01.example.com
      tasks:
        - name: Exclude users and groups
          ansible.builtin.include_role:
            name: rhel-system-roles.tlog
          vars:
            tlog_scope_sssd: all
            tlog_exclude_users_sssd:
              - jeff
              - james
            tlog_exclude_groups_sssd:
              - admins
    tlog_scope_sssd: <value>
    The value all specifies that you want to record all users and groups.
    tlog_exclude_users_sssd: <user_list>
    A YAML list of users user names you want to exclude from the session recording.
    tlog_exclude_groups_sssd: <group_list>
    A YAML list of groups you want to exclude from the session recording.
  2. Validate the playbook syntax:

    $ ansible-playbook --syntax-check ~/playbook.yml

    Note that this command only validates the syntax and does not protect against a wrong but valid configuration.

  3. Run the playbook:

    $ ansible-playbook ~/playbook.yml

Verification

  1. Check the SSSD drop-in file’s content:

    # cat cd /etc/sssd/conf.d/sssd-session-recording.conf

    You can see that the file contains the parameters you set in the playbook.

  2. Log in as a user whose session will be recorded.
  3. Play back a recorded session.

Additional resources

  • /usr/share/ansible/roles/rhel-system-roles.tlog/README.md file
  • /usr/share/doc/rhel-system-roles/tlog/ directory

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