Scaling Privileged Access for Modern Infrastructure: Real-World Insights
Apr 25
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Teleport

Per-session MFA

Teleport - Multi-Factor SSH and Kubectl Authentication

Teleport - Multi-Factor SSH and Kubectl Authentication

Length: 01:29

Teleport supports requiring additional multi-factor authentication checks when starting new:

  • SSH connections (a single tsh ssh call, Web UI SSH session or Teleport Connect SSH session)
  • Kubernetes sessions (a single kubectl call)
  • Database sessions (a single tsh db connect call)
  • Desktop sessions

This is an advanced security feature that protects users against compromises of their on-disk Teleport certificates.

In addition to per-session MFA, enable login MFA in your SSO provider and/or for all local Teleport users to improve security.

Prerequisites

  • A running Teleport cluster. If you want to get started with Teleport, sign up for a free trial or set up a demo environment.

  • The tctl admin tool and tsh client tool version >= 15.2.2.

    On Teleport Enterprise, you must use the Enterprise version of tctl, which you can download from your Teleport account workspace. Otherwise, visit Installation for instructions on downloading tctl and tsh for Teleport Community Edition.

  • To check that you can connect to your Teleport cluster, sign in with tsh login, then verify that you can run tctl commands using your current credentials. tctl is supported on macOS and Linux machines. For example:
    tsh login --proxy=teleport.example.com --user=[email protected]
    tctl status

    Cluster teleport.example.com

    Version 15.2.2

    CA pin sha256:abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678

    If you can connect to the cluster and run the tctl status command, you can use your current credentials to run subsequent tctl commands from your workstation. If you host your own Teleport cluster, you can also run tctl commands on the computer that hosts the Teleport Auth Service for full permissions.
  • WebAuthn configured on this cluster
  • Second factor hardware device, such as YubiKey or SoloKey
  • A Web browser with WebAuthn support (if using SSH or desktop sessions from the Teleport Web UI).
Per-session MFA with FIPS

Teleport FIPS builds disable local users. To configure WebAuthn in order to use per-session MFA with FIPS builds, provide the following in your teleport.yaml:

teleport:
  auth_service:
    local_auth: false
    second_factor: optional
    webauthn:
      rp_id: teleport.example.com

Configure per-session MFA

Per-session MFA can be enforced cluster-wide or only for some specific roles.

Cluster-wide

To enforce MFA checks for all roles, edit your cluster authentication configuration:

Update teleport.yaml on the Auth Server to include the following content:

auth_service:
  authentication:
    # require per-session MFA cluster-wide
    require_session_mfa: yes

Obtain your existing cluster_auth_preference resource:

tctl get cap > cap.yaml

Ensure that cap.yaml contains the following content:

kind: cluster_auth_preference
metadata:
  name: cluster-auth-preference
spec:
  require_session_mfa: true
version: v2

Create the resource:

tctl create -f cap.yaml

Obtain your existing cluster_auth_preference resource:

tctl get cap > cap.yaml

Ensure that cap.yaml contains the following content:

kind: cluster_auth_preference
metadata:
  name: cluster-auth-preference
spec:
  require_session_mfa: true
version: v2

Create the resource:

tctl create -f cap.yaml

Per role

To enforce MFA checks for a specific role, update the role to contain:

kind: role
version: v7
metadata:
  name: example-role-with-mfa
spec:
  options:
    # require per-session MFA for this role
    require_session_mfa: true
  allow:
    ...
  deny:
    ...

Role-specific enforcement only applies when accessing resources matching a role's allow section.

Roles example

Let's walk through an example of setting up per-session MFA checks for roles.

Jerry is an engineer with access to the company infrastructure. The infrastructure is split into development and production environments. Security engineer Olga wants to enforce MFA checks for accessing production servers. Development servers don't require this to reduce engineers' friction.

Olga defines two Teleport roles: access-dev and access-prod:

# access-dev.yaml
kind: role
version: v7
metadata:
  name: access-dev
spec:
  allow:
    node_labels:
      env: dev
    logins:
      - jerry
---
# access-prod.yaml
kind: role
version: v7
metadata:
  name: access-prod
spec:
  options:
    # require per-session MFA for production access
    require_session_mfa: true
  allow:
    node_labels:
      env: prod
    logins:
      - jerry
  deny: {}

Olga then assigns both roles to all engineers, including Jerry.

When Jerry logs into node dev1.example.com (with label env: dev as login jerry), nothing special happens:

But when Jerry logs into node rod3.example.com (with label env: prod as login jerry), he gets prompted for an MFA check:

Tap any security key <tap>


[email protected] >

OTP

If you are using tsh in a constrained environment, you can tell it to use OTP by doing tsh --mfa-mode=otp ssh prod3.example.com.

OTP can only be used with per-session MFA when using tsh or Teleport Connect to establish connections. A hardware MFA key is required for using per-session MFA with Teleport's Web UI.

If per-session MFA was enabled cluster-wide, Jerry would be prompted for MFA even when logging into dev1.example.com.

Per-session MFA for Database Access

The Teleport Database Service supports per-connection MFA. When Jerry connects to the database prod-mysql-instance (with label env: prod), he gets prompted for an MFA check for each tsh db connect or tsh proxy db call:

tsh db connect prod-mysql-instance

Tap any security key


Welcome to the MySQL monitor. Commands end with ; or \g.

Your MySQL connection id is 10002

Server version: 8.0.0-Teleport (Ubuntu)

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its

affiliates. Other names may be trademarks of their respective

owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>

Limitations

Current limitations for this feature are:

  • For SSH connections besides the Web UI, the tsh or Teleport Connect client must be used for per-session MFA. (The OpenSSH ssh client does not work with per-session MFA).
  • Only kubectl supports per-session WebAuthn authentication for Kubernetes.
  • Database access with per-session MFA only works with tsh db connect or tsh proxy db --tunnel. Per-session MFA for databases is not supported in Teleport Connect.
  • Application access clients don't support per-session MFA authentication yet, although cluster and role configuration applies to them. If you enable per-session MFA checks cluster-wide, you will not be able to use Application access. We're working on integrating per-session MFA checks for these clients.
  • For desktop access, only WebAuthn devices are supported.