Securely record SSH sessions on RHEL in a private VPC network

On this weblog put up, you’ll discover ways to report SSH periods on a Purple Hat Enterprise Linux (RHEL) VSI in a non-public VPC community utilizing in-built packages. The VPC non-public community is provisioned by Terraform and the RHEL packages are put in utilizing Ansible automation. Moreover, you’ll discover ways to arrange a extremely out there bastion host.

What’s session recording and why is it required?

A bastion host and a bounce server are each safety mechanisms utilized in community and server environments to regulate and improve safety when connecting to distant techniques. They serve comparable functions however have some variations of their implementation and use instances. The bastion host is positioned in entrance of the non-public community to take SSH requests from public site visitors and move the request to the downstream machine. Bastion host and bounce servers are susceptible to intrusion as a result of they’re uncovered to public site visitors.

Session recording helps an administrator of a system to audit consumer SSH periods and ensure they adjust to regulatory necessities. Within the occasion of a safety breach, the administrator will need to audit and analyze the consumer periods. That is essential for a security-sensitive system.

What’s a non-public VPC community?

A virtual private cloud is totally non-public if there is no such thing as a public ingress or outgress community site visitors. In easy technical phrases, it’s non-public if there are not any public gateways on the subnets (non-public subnets) and no floating IPs on the Digital Server Cases (VSIs).

How do I connect with the non-public VPC community?

Shopper-to-site VPN for VPC is likely one of the two VPN choices out there on IBM Cloud, and it permits customers to hook up with IBM Cloud assets by safe, encrypted connections.

The client-to-site VPN is very out there, with two VPN servers which can be created in two completely different availability zones in the identical area. The bastions are extremely out there as nicely.

Stipulations

Provision the non-public VPC community utilizing Terraform

• Upon getting the IBM Cloud Secrets Manager secret with the certificates, launch your terminal and set the next Terraform variables:

export TF_VAR_ibmcloud_api_key=<IBM_CLOUD_API_KEY>

export TF_VAR_secrets_manager_certificate_crn=<SECRET_CRN>

git clone https://github.com/VidyasagarMSC/private-vpc-network

cd terraform

• Run the Terraform instructions to provision the VPC assets (e.g., subnets, bastion hosts (VSIs), VPN, and many others.):

terraform init

terraform plan

terraform apply

Connect with client-to-site VPN

• As soon as the VPC assets are efficiently provisioned, it is advisable to obtain the VPN consumer profile by navigating to VPN servers page on IBM Cloud.
• Click on the Shopper-to-site servers tab after which on the title of the VPN:

• Obtain the profile from the Purchasers tab.
• The VPN provisioned by Terraform makes use of certificates. Observe the instructions here to hook up with the OpenVPN Shopper.
• It is best to see the profitable connection in your OpenVPN Shopper:

Confirm the SSH connection

• On a terminal, add the SSH non-public key to the SSH agent with the next command:

ssh-add <LOCATION_OF_PRIVATE_SSH_KEY> 

• Instance: ssh-add ~/.ssh/<NAME_OF_THE_PRIVATE_KEY>
• Run the next command to SSH into the RHEL VSI by a bastion host. You can be utilizing the non-public IP tackle of the bastion in Zone 1:

ssh -J root@10.10.0.13 root@10.10.128.13

• Bear in mind, try to be related to the client-to-site VPN to entry the RHEL VSI by the bastion host.
• After SSH, It is best to see directions to allow SSH session recording utilizing the TLOG bundle on RHEL.

Deploy session recording utilizing Ansible

To deploy the session recording answer, it is advisable to have the next packages put in on the RHEL VSI:

• tlog
• SSSD
• cockpit-session-recording

The packages will probably be put in by Ansible automation on all of the VSIs—each bastion hosts and RHEL VSI.

• Transfer to the Ansible folder:

cd ansible

• Create hosts.ini from the template file:

cp hosts_template.ini hosts.ini

• Run the Ansible playbook to put in the packages from an IBM Cloud non-public mirror/repository:

ansible-playbook main_playbook.yml -i hosts.ini --flush-cache

You’ll be able to see in Determine 1 that after you SSH into the RHEL machine, you will note a word saying: ATTENTION! Your session is being recorded!

Verify the session recordings, logs and experiences

If you happen to carefully observe the messages post-SSH, you will note a URL to the net console that may be accessed utilizing the machine title or non-public IP over port 9090. To permit site visitors on port 9090, within the Terraform code, change the worth of allow_port_9090 variable to true and run terraform apply. The newest terraform apply will add ACL and safety group guidelines to permit site visitors on port 9090.

• Now, open a browser and navigate to http://10.10.128.13:9090. To entry utilizing the VSI title, it is advisable to arrange a non-public DNS (out of scope for this text). You want a root password to entry the net console:

• Navigate to Session Recording on the left-hand aspect to see the listing of session recordings. Together with session recordings, you may verify the logs, diagnostic experiences, and many others.:

Advisable studying

Conclusion

This text lined why session recording is required in bastion hosts for auditing and compliance and the way session recording may be arrange with the built-in RHEL packages utilizing Ansible Automation.

Whereas designing a secured digital non-public cloud community, you discovered the most effective practices in architecting a VPC non-public community. We additionally lined the necessity to construct extremely out there VPN servers and bastion hosts. With the provisioning of cloud infrastructure utilizing Terraform and Ansible for session recording, you bought hands-on expertise.

Learn more about IBM Cloud VPC

If in case you have any queries, be happy to succeed in out to me on Twitter or on LinkedIn.