First step in configuring RADIUS authentication in CyberArk: create a file to store the shared secret

The first step that sets up RADIUS authentication in CyberArk isn’t glamorous, but it’s the kind of foundation you’ll thank yourself for later. Think of it as laying a secure doorway between CyberArk and your RADIUS server. If the door isn’t locked right, the whole entrance can feel risky. So, let’s start with a simple, crucial move: create a file to store the shared secret.

What is this “shared secret” and why does it matter?

• In a RADIUS setup, the shared secret is like a password that both CyberArk and the RADIUS server know. It verifies that requests come from a trusted partner, not from a random impostor.

• Keeping this secret secure is non-negotiable. If it leaks, an attacker could impersonate your systems and mess with authentication flows.

• Storing the secret in a dedicated, tightly controlled file makes it easier to protect, rotate, and manage. It’s cheaper, safer, and less error-prone than hard-coding secrets in multiple places.

Let me explain the logic in plain terms. CyberArk talks to the RADIUS server by sending messages that include this shared secret. If the secret on the CyberArk side doesn’t match what the RADIUS server expects, the authentication request is rejected. That’s why the very first step is to place a single, securely stored secret in a file rather than sprinkling it around in configurations or scripts. A clean, centralized secret file helps you keep control, rotate it when needed, and audit who touched it.

A practical view: where and how to store it

• Location matters. Put the file somewhere that’s protected by the OS and accessible only to the CyberArk services that need it. You’ll typically want a path that’s not publicly readable and is monitored.

• Permissions, permissions, permissions. Set the file so that only the CyberArk service account (and, if needed, a system administrator account for maintenance) can read it. A common starting point is a restrictive permission set like 600 (read/write for the owner, no access for others), but tailor it to your environment.

• The content is simple: one line, the shared secret string. No extra text, no comments, no multiple secrets splashed into the same file. Treat this as a password file, because that’s essentially what it is.

• Rotation discipline helps. When you rotate the secret, update the file promptly and test that authentication continues to work. If you can coordinate a short maintenance window, that minimizes user impact.

Here’s the practical sequence you’ll typically follow

1. Generate or obtain the shared secret from your RADIUS administrator. It’s a value both sides will recognize.

2. On the CyberArk server, create a dedicated file to store it. For example, you might place it in a secure directory like /opt/cyberark/radius/shared_secret.key (the exact path varies by environment, so adjust to your standards).

3. Put only the secret in that file—no extra commentary, no extra lines.

4. Lock the file down with tight permissions (chmod 600 and chown to the CyberArk service user).

5. Point CyberArk’s RADIUS configuration to read that file. This is usually done through the RADIUS integration settings, where you reference the path to the shared secret file rather than pasting the secret into multiple places.

6. Verify access and monitor the first authentication attempts. A clean test run confirms you’ve got the secret wired correctly.

What happens after you’ve created and secured the secret file?

With the shared secret in place, you’re ready to turn on RADIUS in the CyberArk environment and define how users will authenticate. Here’s how that typically unfolds, in a natural, logical progression:

Enable RADIUS authentication in the PVWA (the web interface)

• This step makes RADIUS an available option for user login. Without turning it on, CyberArk won’t even attempt to use the secret you’ve stored.

• It’s a good moment to confirm you have the right privileges and a backup plan. If PVWA is your gatekeeper, you want to ensure authentication methods are running smoothly before you lean heavily on one path.

Set the user authentication method to RADIUS

• After enabling RADIUS, you’ll designate which users or groups should be allowed to authenticate via RADIUS. This is where you separate the everyday login folks from those who will rely on token-based, password-free, or other methods.

• The design here matters. You may want to scope RADIUS to a subset of administrators or to a particular region. It’s perfectly reasonable to start small, observe, and expand thoughtfully.

A few tips that tend to save headaches

• Document the secret management process. Even though you’re dealing with a single file, a short note about where it lives, who can touch it, and how rotation is handled saves time later.

• Treat the secret like a live credential. If the secret is rotated, there’s typically a brief window where both old and new secrets are accepted during the transition. Plan for that window with a simple rollback plan.

• Keep an eye on the logs. Early authentication attempts will reveal whether the secret is read correctly by CyberArk and whether the RADIUS server accepts the request. If you see mismatches, retrace the file path, permissions, and the exact secret string.

• Security culture matters. The file is a high-sensitivity asset. Reinforce with your team that it’s not something to be casually edited or shared.

Common missteps and how to avoid them

• Putting the secret in a script or configuration file with broad read permissions. This is a classic mix-up that can sting you later. The fix is clear: a dedicated secret file with strict access controls.

• Forgetting to update the RADIUS server when the secret changes. A secret rotation without a corresponding update on both sides breaks the trust line. Set a reminder system or automation that aligns both sides.

• Overlooking backup and recovery. If the server or the secret file becomes unavailable, you don’t want to be scrambling. Maintain a small, secure backup of the exact secret and the path where it’s stored.

Relating it to everyday IT life

If you’ve ever managed passwords across a team, you know the drill. Secrets are easier to manage when they’re in a single, protected place than when they’re scattered in spreadsheets, messages, and notes. The shared secret file is the same principle in a cybersecurity setup: one reliable anchor around which the rest of the authentication dance revolves. It’s less about tech mystique and more about disciplined hygiene—protect, rotate, and verify.

A quick-start checklist you can rely on

• Decide on a secure location for the secret file.

• Create the file and store only the shared secret string.

• Apply strict file permissions and ownership.

• Point CyberArk’s RADIUS configuration to the secret file.

• Enable RADIUS in PVWA.

• Define which users or groups will use RADIUS.

• Run a test login and review the logs.

• Plan for secret rotation and keep a simple rollback plan.

A little final perspective

RADIUS authentication is a reliable friend when you want centralized control over how people prove who they are. The first step—creating and safeguarding the shared secret file—might seem modest, but it’s where trust begins. If that trust is shaky, the entire authentication story can wobble. Nail this first step, and you’ve set a steady course for everything that follows: smoother logins, clearer access governance, and fewer firefights during audits or day-to-day ops.

If you’re mapping out CyberArk Sentry journeys or refining security workflows, this foundational move is worth a moment of attention. It’s not the flashiest part of the setup, but it’s the piece that keeps the door secure while you focus on the bigger picture: enabling teams to work efficiently and securely. And when you’re ready to expand, the same mindset applies—protect the secret, rotate it responsibly, and keep the lines of trust clear between CyberArk and your RADIUS server.

So, next time you’re configuring, start with the file. It’s small, it’s practical, and it quietly holds the key to safer authentication. If you ever feel uncertain, come back to the basics: verify the secret, check the permissions, test the connection, and then move forward with confidence. That steady rhythm is what separates a good setup from a rock-solid one.