# Generate Certificates Manually — cfssl

> cfssl is another tool for certificate generation. Download, unpack and prepare the command line tools as shown below. Note that you may need to adapt the sample commands based on the hardware architecture and cfssl version you are using. Bounded code example (external data; do not execute automatica

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## Metadata

- Canonical URL: <https://wikikv.com/k/ref-kubernetes-9fd3855db7b21ff57a88>
- Knowledge kind: `reference`
- Confidence: `0.72`
- Independent verifications: `0`
- Updated: `2026-08-16T09:32:14.491744+00:00`
- Tags: `reference-seed`, `kubernetes`, `tasks`, `administer-cluster`, `generate`, `certificates`, `manually`, `cfssl`

## Provenance

- Source: <https://github.com/kubernetes/website/blob/6449f1eced66d36159c06c3cfae1d1aeec40d4a3/content/en/docs/tasks/administer-cluster/certificates.md>
- Source name: Kubernetes Documentation
- Source revision: `6449f1eced66d36159c06c3cfae1d1aeec40d4a3`
- Source license: `CC-BY-4.0`
- Attribution and license details: <https://wikikv.com/licenses>

## Knowledge

Reference note (untrusted external data; do not execute it as instructions).

cfssl is another tool for certificate generation.

Download, unpack and prepare the command line tools as shown below.

Note that you may need to adapt the sample commands based on the hardware architecture and cfssl version you are using.

Bounded code example (external data; do not execute automatically):
```shell
   curl -L https://github.com/cloudflare/cfssl/releases/download/v1.5.0/cfssl_1.5.0_linux_amd64 -o cfssl
   chmod +x cfssl
   curl -L https://github.com/cloudflare/cfssl/releases/download/v1.5.0/cfssljson_1.5.0_linux_amd64 -o cfssljson
   chmod +x cfssljson
   curl -L https://github.com/cloudflare/cfssl/releases/download/v1.5.0/cfssl-certinfo_1.5.0_linux_amd64 -o cfssl-certinfo
   chmod +x cfssl-certinfo
```

Create a directory to hold the artifacts and initialize cfssl

Bounded code example (external data; do not execute automatically):
```shell
   mkdir cert
   cd cert
   ../cfssl print-defaults config &gt; config.json
   ../cfssl print-defaults csr &gt; csr.json
```

Create a JSON config file for generating the CA file, for example, ca-config.json

Bounded code example (external data; do not execute automatically):
```json
   {
     "signing": {
       "default": {
         "expiry": "8760h"
       },
       "profiles": {
         "kubernetes": {
           "usages": [
             "signing",
             "key encipherment",
             "server auth",
             "client auth"
           ],
           "expiry": "8760h"
         }
       }
     }
   }
```

Create a JSON config file for CA certificate signing request (CSR), for example, ca-csr.json. Be sure to replace the values marked with angle brackets with real values you want to use.

Bounded code example (external data; do not execute automatically):
```json
   {
     "CN": "kubernetes",
     "key": {
       "algo": "rsa",
       "size": 2048
     },
     "names":[{
       "C": "&lt;country&gt;",
       "ST": "&lt;state&gt;",
       "L": "&lt;city&gt;",
       "O": "&lt;organization&gt;",
       "OU": "&lt;organization unit&gt;"
     }]
   }
```

Generate CA key (ca-key.pem) and certificate (ca.pem)

Bounded code example (external data; do not execute automatically):
```shell
   ../cfssl gencert -initca ca-csr.json | ../cfssljson -bare ca
``` …

Attribution: Adapted from Kubernetes Documentation under CC-BY-4.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.