Security Practices

Secure coding practices

Least-privilege permissions, standard cryptographic primitives, controller-safe execution, and careful handling of secrets in memory and logs.

Decision matrix

Secure coding defaults

Secure coding defaults.

Area	Expected default	Avoid
Filesystem permissions	Use the narrowest permissions possible, especially 0600 for keys and secrets.	World-writable or broadly readable secret material.
Randomness	Use crypto/rand for security-sensitive values.	math/rand for tokens, passwords, keys, or nonces.
Controller execution model	Use Go libraries and Kubernetes clients directly.	Shelling out to kubectl, helm, bao, vault, or similar binaries from controllers.
Input validation	Validate paths, ranges, and other CR-driven input before use.	Passing raw user input into filesystem or runtime-sensitive operations.
Secret handling	Do not log secret contents and minimize their lifetime in memory.	Debug output that prints token, key, or secret payload fields.

Minimal secure examples

// private key file permissions
if err := os.WriteFile(keyPath, keyData, 0o600); err != nil {
    return err
}

// cryptographically secure randomness
token := make([]byte, 32)
if _, err := rand.Read(token); err != nil {
    return err
}

Controllers must not shell out

Shelling out introduces injection risk, hidden runtime dependencies, and slower, harder-to-test control paths. Use Kubernetes clients and internal helpers instead.

Input and secret handling

• Clean and validate filesystem paths before use.
• Enforce numeric and enum bounds from CR input explicitly.
• Never log secret payloads, even in debug-only paths.
• Zero sensitive byte slices after use when the code keeps them in memory for any meaningful period.

Related secure-contributor guides

Supply chain securityOpen the artifact-trust controls when the change moves from secure coding into build, provenance, or release security.Dependency license policyUse the dependency policy when the security question is whether a new dependency is even shippable.Security docsReturn to the operator-facing security section when you need the runtime trust model rather than contributor implementation rules.