# Source: https://docs.datadoghq.com/security/code_security/iac_security/iac_rules/k8s/client_certificate_authentication_not_setup_properly.md

---
title: Client certificate authentication not set up properly
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: >-
  Docs > Datadog Security > Code Security > Infrastructure as Code (IaC)
  Security > IaC Security Rules > Client certificate authentication not set up
  properly
---

# Client certificate authentication not set up properly

{% callout %}
# Important note for users on the following Datadog sites: app.ddog-gov.com

{% alert level="danger" %}
This product is not supported for your selected [Datadog site](https://docs.datadoghq.com/getting_started/site). ().
{% /alert %}

{% /callout %}

## Metadata{% #metadata %}

**Id:** `e0e00aba-5f1c-4981-a542-9a9563c0ee20`

**Cloud Provider:** Kubernetes

**Platform:** Kubernetes

**Severity:** High

**Category:** Access Control

#### Learn More{% #learn-more %}

- [Provider Reference](https://kubernetes.io/docs/reference/command-line-tools-reference/kubelet/)

### Description{% #description %}

Client certificate authentication must be configured using a `.pem` or `.crt` file. Containers running `kube-apiserver` or `kubelet` must include the `--client-ca-file` flag that references a `.pem` or `.crt` certificate. For KubeletConfiguration, the `authentication.x509.clientCAFile` field must reference a `.pem` or `.crt` file.

## Compliant Code Examples{% #compliant-code-examples %}

```yaml
apiVersion: v1
kind: Pod
metadata:
  name: command-demo
  labels:
    purpose: demonstrate-command
spec:
  containers:
    - name: command-demo-container
      image: foo/bar
      command: ["kubelet"]
      args: ["--client-ca-file=/var/lib/ca.pem"]
  restartPolicy: OnFailure
```

```yaml
apiVersion: v1
kind: Pod
metadata:
  name: command-demo
  labels:
    purpose: demonstrate-command
spec:
  containers:
    - name: command-demo-container
      image: gcr.io/google_containers/kube-apiserver-amd64:v1.6.0
      command: ["kube-apiserver"]
      args: ["--client-ca-file=/var/lib/ca.crt"]
  restartPolicy: OnFailure
```

```yaml
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
address: "192.168.0.8"
port: 20250
protectKernelDefaults: false
serializeImagePulls: false
authentication:
  anonymous:
    enabled: false
  webhook:
    enabled: true
  x509:
    clientCAFile: "/var/lib/kubernetes/ca.crt"
authorization:
evictionHard:
    memory.available:  "200Mi"
```

## Non-Compliant Code Examples{% #non-compliant-code-examples %}

```yaml
apiVersion: v1
kind: Pod
metadata:
  name: command-demo
  labels:
    purpose: demonstrate-command
spec:
  containers:
    - name: command-demo-container
      image: gcr.io/google_containers/kube-apiserver-amd64:v1.6.0
      command: ["kube-apiserver"]
      args: ["--client-ca-file=/var/lib/ca.txt"]
  restartPolicy: OnFailure
```

```yaml
apiVersion: v1
kind: Pod
metadata:
  name: command-demo
  labels:
    purpose: demonstrate-command
spec:
  containers:
    - name: command-demo-container
      image: gcr.io/google_containers/kube-apiserver-amd64:v1.6.0
      command: ["kube-apiserver"]
      args: []
  restartPolicy: OnFailure
```

```yaml
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
address: "192.168.0.8"
port: 20250
protectKernelDefaults: false
serializeImagePulls: false
authentication:
  anonymous:
    enabled: false
  webhook:
    enabled: true
  x509:
    clientCAFile: "/var/lib/kubernetes/ca.txt"
authorization:
evictionHard:
    memory.available:  "200Mi"
```