Locking Down the VPN Operating System: SELinux and IMA

In today’s cloud-first and zero trust environments, traditional VPNs fall short of the security guarantees modern infrastructure demands. While encryption protects data in transit, it does little to defend against threats that target the system itself—such as unsigned binaries, configuration tampering, or privilege escalation via zero day exploits.

Just recently, Google reported that 75 zero-day vulnerabilities have been actively exploited in 2024, including several targeting enterprise VPN platforms — highlighting how critical hardened foundational security has become. See the full story on The Hacker News.

At JET Technology Labs, SecureKey VPN is built with a hardened operating system foundation that goes far beyond encryption. We use two powerful Linux security technologies—SELinux and Integrity Measurement Architecture (IMA)—to enforce a runtime environment where only trusted code runs, and no process can act outside its defined boundaries.

SELinux: Mandatory Access Control Done Right

SELinux, or Security-Enhanced Linux, provides mandatory access control at the kernel level. Unlike traditional discretionary access controls that depend on user ownership and permissions, SELinux enforces a strict set of rules that define which processes can interact with which files, sockets, and other system resources.

In SecureKey VPN, we define custom SELinux policies to isolate and restrict the behavior of each component. The VPN service runs in a tightly confined domain with only the minimal permissions needed to operate. Even if an attacker were to gain root access, SELinux policies would prevent unauthorized actions like writing to configuration files, injecting code into system daemons, or spawning privileged shells.

By following the principle of least privilege, SELinux ensures that a single point of compromise cannot lead to full system control.

IMA: Cryptographic Integrity for the Entire Stack

While SELinux governs access control, it doesn’t verify whether a binary is trustworthy. That’s where Integrity Measurement Architecture (IMA) comes in.

IMA provides cryptographic validation of files at runtime. Every executable, script, or configuration file is signed during the build process. When the system boots or loads these files, the kernel verifies the signature before allowing access. If the signature is invalid or missing, the action is denied.

The SecureKey Software Development Kit (SDK) is used to sign every file in the system. At boot time, the operating system enforces an IMA policy that blocks execution of anything that isn't signed and trusted. This eliminates entire classes of attacks, such as tampering with configuration files, dropping backdoor binaries, or modifying shared libraries. This request for proof follows the trust chain from build time to runtime.

Combined Protection: SELinux and IMA Together

SELinux and IMA complement each other to provide layered, defense-in-depth security. IMA ensures that only signed and authorized binaries are loaded and executed. SELinux ensures that even those binaries operate within strict, predefined boundaries.

Together, they create a trusted execution environment where:

• Code execution is cryptographically validated at the file level.

• Runtime behavior is tightly confined by policy.

• Root-level access does not imply full control over the system.

This integrated enforcement model significantly reduces the risk of both known and unknown vulnerabilities being exploited in real-world deployments—exactly the kind of threat highlighted in recent VPN zero-day exploits.

SecureKey Crypto: Protecting Keys Where They Matter

The final layer of defense in SecureKey VPN is our proprietary SecureKey Crypto engine. Unlike traditional cryptographic libraries, which expose keys in memory, SecureKey ensures that cryptographic keys are encrypted in memory and only decrypted temporarily inside CPU registers during computation.

This eliminates the risk of secrets being leaked through memory scraping, kernel exploits, DMA-based attacks, or advanced side-channel techniques. Even if an attacker compromises the operating system, they cannot extract VPN session keys or certificates.

When combined with a locked-down operating system built on SELinux and IMA, SecureKey Crypto offers an unparalleled level of protection against zero-day threats.

Built for Critical Infrastructure

SecureKey VPN is designed for high-assurance environments that cannot afford compromise. Our SDK enables developers and integrators to sign binaries and configuration files during build time, generate custom SELinux policy modules, and deploy hardened systems across cloud, on-prem, or secure enclave environments.

With SecureKey VPN, security is enforced at every layer - from cryptographic identity to execution policy. No shortcuts. No assumptions. Just provable trust.